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-rw-r--r--lib/pure/algorithm.nim115
-rw-r--r--lib/pure/collections/critbits.nim18
-rw-r--r--lib/pure/colors.nim22
-rw-r--r--lib/pure/complex.nim4
-rw-r--r--lib/pure/httpclient.nim38
-rw-r--r--lib/pure/json.nim528
-rw-r--r--lib/pure/math.nim276
-rw-r--r--lib/pure/net.nim1
-rw-r--r--lib/pure/os.nim39
-rw-r--r--lib/pure/parsejson.nim535
-rw-r--r--lib/pure/parseutils.nim3
-rw-r--r--lib/pure/pegs.nim76
-rw-r--r--lib/pure/rationals.nim36
-rw-r--r--lib/pure/streams.nim32
-rw-r--r--lib/pure/strformat.nim31
-rw-r--r--lib/pure/strscans.nim19
-rw-r--r--lib/pure/strutils.nim7
-rw-r--r--lib/pure/times.nim721
-rw-r--r--lib/pure/unicode.nim8
-rw-r--r--lib/pure/unittest.nim10
-rw-r--r--lib/pure/xmltree.nim26
21 files changed, 1591 insertions, 954 deletions
diff --git a/lib/pure/algorithm.nim b/lib/pure/algorithm.nim
index 22793ab1c..81badfae6 100644
--- a/lib/pure/algorithm.nim
+++ b/lib/pure/algorithm.nim
@@ -64,40 +64,72 @@ proc reversed*[T](a: openArray[T]): seq[T] =
   ## returns the reverse of the array `a`.
   reversed(a, 0, a.high)
 
-proc binarySearch*[T](a: openArray[T], key: T): int =
+proc binarySearch*[T, K](a: openArray[T], key: K,
+              cmp: proc (x: T, y: K): int {.closure.}): int =
   ## binary search for `key` in `a`. Returns -1 if not found.
-  if ((a.len - 1) and a.len) == 0 and a.len > 0:
-    # when `a.len` is a power of 2, a faster div can be used.
-    var step = a.len div 2
+  ##
+  ## `cmp` is the comparator function to use, the expected return values are
+  ## the same as that of system.cmp.
+  if a.len == 0:
+    return -1
+
+  let len = a.len
+
+  if len == 1:
+    if cmp(a[0], key) == 0:
+      return 0
+    else:
+      return -1
+
+  if (len and (len - 1)) == 0:
+    # when `len` is a power of 2, a faster shr can be used.
+    var step = len shr 1
+    var cmpRes: int
     while step > 0:
-      if a[result or step] <= key:
-        result = result or step
+      let i = result or step
+      cmpRes = cmp(a[i], key)
+      if cmpRes == 0:
+        return i
+
+      if cmpRes < 1:
+        result = i
       step = step shr 1
-    if a[result] != key: result = -1
+    if cmp(a[result], key) != 0: result = -1
   else:
-    var b = len(a)
+    var b = len
+    var cmpRes: int
     while result < b:
-      var mid = (result + b) div 2
-      if a[mid] < key: result = mid + 1
-      else: b = mid
-    if result >= len(a) or a[result] != key: result = -1
+      var mid = (result + b) shr 1
+      cmpRes = cmp(a[mid], key)
+      if cmpRes == 0:
+        return mid
+
+      if cmpRes < 0:
+        result = mid + 1
+      else:
+        b = mid
+    if result >= len or cmp(a[result], key) != 0: result = -1
+
+proc binarySearch*[T](a: openArray[T], key: T): int =
+  ## binary search for `key` in `a`. Returns -1 if not found.
+  binarySearch(a, key, cmp[T])
 
 proc smartBinarySearch*[T](a: openArray[T], key: T): int {.deprecated.} =
   ## **Deprecated since version 0.18.1**; Use ``binarySearch`` instead.
-  binarySearch(a,key)
+  binarySearch(a, key, cmp[T])
 
 const
   onlySafeCode = true
 
 proc lowerBound*[T, K](a: openArray[T], key: K, cmp: proc(x: T, k: K): int {.closure.}): int =
-  ## same as binarySearch except that if key is not in `a` then this
-  ## returns the location where `key` would be if it were. In other
-  ## words if you have a sorted sequence and you call
+  ## Returns a position to the first element in the `a` that is greater than `key`, or last
+  ## if no such element is found. In other words if you have a sorted sequence and you call
   ## insert(thing, elm, lowerBound(thing, elm))
   ## the sequence will still be sorted.
   ##
-  ## `cmp` is the comparator function to use, the expected return values are
+  ## The first version uses `cmp` to compare the elements. The expected return values are
   ## the same as that of system.cmp.
+  ## The second version uses the default comparison function `cmp`.
   ##
   ## example::
   ##
@@ -108,7 +140,7 @@ proc lowerBound*[T, K](a: openArray[T], key: K, cmp: proc(x: T, k: K): int {.clo
   var count = a.high - a.low + 1
   var step, pos: int
   while count != 0:
-    step = count div 2
+    step = count shr 1
     pos = result + step
     if cmp(a[pos], key) < 0:
       result = pos + 1
@@ -118,6 +150,36 @@ proc lowerBound*[T, K](a: openArray[T], key: K, cmp: proc(x: T, k: K): int {.clo
 
 proc lowerBound*[T](a: openArray[T], key: T): int = lowerBound(a, key, cmp[T])
 
+proc upperBound*[T, K](a: openArray[T], key: K, cmp: proc(x: T, k: K): int {.closure.}): int =
+  ## Returns a position to the first element in the `a` that is not less
+  ## (i.e. greater or equal to) than `key`, or last if no such element is found.
+  ## In other words if you have a sorted sequence and you call
+  ## insert(thing, elm, upperBound(thing, elm))
+  ## the sequence will still be sorted.
+  ##
+  ## The first version uses `cmp` to compare the elements. The expected return values are
+  ## the same as that of system.cmp.
+  ## The second version uses the default comparison function `cmp`.
+  ##
+  ## example::
+  ##
+  ##   var arr = @[1,2,3,4,6,7,8,9]
+  ##   arr.insert(5, arr.upperBound(4))
+  ##   # after running the above arr is `[1,2,3,4,5,6,7,8,9]`
+  result = a.low
+  var count = a.high - a.low + 1
+  var step, pos: int
+  while count != 0:
+    step = count shr 1
+    pos = result + step
+    if cmp(a[pos], key) <= 0:
+      result = pos + 1
+      count -= step + 1
+    else:
+      count = step
+
+proc upperBound*[T](a: openArray[T], key: T): int = upperBound(a, key, cmp[T])
+
 template `<-` (a, b) =
   when false:
     a = b
@@ -514,21 +576,26 @@ when isMainModule:
     doAssert lowerBound([1,2,2,3], 4, system.cmp[int]) == 4
     doAssert lowerBound([1,2,3,10], 11) == 4
 
+  block upperBound:
+    doAssert upperBound([1,2,4], 3, system.cmp[int]) == 2
+    doAssert upperBound([1,2,2,3], 3, system.cmp[int]) == 4
+    doAssert upperBound([1,2,3,5], 3) == 3
+
   block fillEmptySeq:
     var s = newSeq[int]()
     s.fill(0)
 
   block testBinarySearch:
     var noData: seq[int]
-    doAssert binarySearch(noData, 7)    == -1
+    doAssert binarySearch(noData, 7) == -1
     let oneData = @[1]
-    doAssert binarySearch(oneData, 1)   == 0
-    doAssert binarySearch(onedata, 7)   == -1
+    doAssert binarySearch(oneData, 1) == 0
+    doAssert binarySearch(onedata, 7) == -1
     let someData = @[1,3,4,7]
-    doAssert binarySearch(someData, 1)  == 0
-    doAssert binarySearch(somedata, 7)  == 3
+    doAssert binarySearch(someData, 1) == 0
+    doAssert binarySearch(somedata, 7) == 3
     doAssert binarySearch(someData, -1) == -1
-    doAssert binarySearch(someData, 5)  == -1
+    doAssert binarySearch(someData, 5) == -1
     doAssert binarySearch(someData, 13) == -1
     let moreData = @[1,3,5,7,4711]
     doAssert binarySearch(moreData, -1) == -1
diff --git a/lib/pure/collections/critbits.nim b/lib/pure/collections/critbits.nim
index 95fffdf88..5ae5e26b2 100644
--- a/lib/pure/collections/critbits.nim
+++ b/lib/pure/collections/critbits.nim
@@ -163,13 +163,13 @@ proc containsOrIncl*(c: var CritBitTree[void], key: string): bool =
   var n = rawInsert(c, key)
   result = c.count == oldCount
 
-proc inc*(c: var CritBitTree[int]; key: string) =
-  ## counts the 'key'.
+proc inc*(c: var CritBitTree[int]; key: string, val: int = 1) =
+  ## increments `c[key]` by `val`.
   let oldCount = c.count
   var n = rawInsert(c, key)
-  if c.count == oldCount:
+  if c.count == oldCount or oldCount == 0:
     # not a new key:
-    inc n.val
+    inc n.val, val
 
 proc incl*(c: var CritBitTree[void], key: string) =
   ## includes `key` in `c`.
@@ -352,3 +352,13 @@ when isMainModule:
   assert toSeq(r.items) == @["abc", "definition", "prefix", "xyz"]
 
   assert toSeq(r.itemsWithPrefix("de")) == @["definition"]
+  var c = CritBitTree[int]()
+
+  c.inc("a")
+  assert c["a"] == 1
+
+  c.inc("a", 4)
+  assert c["a"] == 5
+
+  c.inc("a", -5)
+  assert c["a"] == 0
diff --git a/lib/pure/colors.nim b/lib/pure/colors.nim
index 25a2fb870..843f29a63 100644
--- a/lib/pure/colors.nim
+++ b/lib/pure/colors.nim
@@ -10,6 +10,7 @@
 ## the ``graphics`` module.
 
 import strutils
+from algorithm import binarySearch
 
 type
   Color* = distinct int ## a color stored as RGB
@@ -371,37 +372,28 @@ proc `$`*(c: Color): string =
   ## converts a color into its textual representation. Example: ``#00FF00``.
   result = '#' & toHex(int(c), 6)
 
-proc binaryStrSearch(x: openArray[tuple[name: string, col: Color]],
-                     y: string): int =
-  var a = 0
-  var b = len(x) - 1
-  while a <= b:
-    var mid = (a + b) div 2
-    var c = cmp(x[mid].name, y)
-    if c < 0: a = mid + 1
-    elif c > 0: b = mid - 1
-    else: return mid
-  result = - 1
+proc colorNameCmp(x: tuple[name: string, col: Color], y: string): int =
+  result = cmpIgnoreCase(x.name, y)
 
 proc parseColor*(name: string): Color =
   ## parses `name` to a color value. If no valid color could be
-  ## parsed ``EInvalidValue`` is raised.
+  ## parsed ``EInvalidValue`` is raised. Case insensitive.
   if name[0] == '#':
     result = Color(parseHexInt(name))
   else:
-    var idx = binaryStrSearch(colorNames, name)
+    var idx = binarySearch(colorNames, name, colorNameCmp)
     if idx < 0: raise newException(ValueError, "unknown color: " & name)
     result = colorNames[idx][1]
 
 proc isColor*(name: string): bool =
   ## returns true if `name` is a known color name or a hexadecimal color
-  ## prefixed with ``#``.
+  ## prefixed with ``#``. Case insensitive.
   if name[0] == '#':
     for i in 1 .. name.len-1:
       if name[i] notin {'0'..'9', 'a'..'f', 'A'..'F'}: return false
     result = true
   else:
-    result = binaryStrSearch(colorNames, name) >= 0
+    result = binarySearch(colorNames, name, colorNameCmp) >= 0
 
 proc rgb*(r, g, b: range[0..255]): Color =
   ## constructs a color from RGB values.
diff --git a/lib/pure/complex.nim b/lib/pure/complex.nim
index 98cab1a5a..ba5c571ce 100644
--- a/lib/pure/complex.nim
+++ b/lib/pure/complex.nim
@@ -25,6 +25,10 @@ type
   Complex* = tuple[re, im: float]
     ## a complex number, consisting of a real and an imaginary part
 
+const
+  im*: Complex = (re: 0.0, im: 1.0)
+    ## The imaginary unit. √-1.
+
 proc toComplex*(x: SomeInteger): Complex =
   ## Convert some integer ``x`` to a complex number.
   result.re = x
diff --git a/lib/pure/httpclient.nim b/lib/pure/httpclient.nim
index 3f1a3d067..8530e4c42 100644
--- a/lib/pure/httpclient.nim
+++ b/lib/pure/httpclient.nim
@@ -362,15 +362,13 @@ when not defined(ssl):
   type SSLContext = ref object
 var defaultSSLContext {.threadvar.}: SSLContext
 
-when defined(ssl):
-  defaultSSLContext = newContext(verifyMode = CVerifyNone)
-  template contextOrDefault(ctx: SSLContext): SSLContext =
-    var result = ctx
-    if ctx == nil:
-      if defaultSSLContext == nil:
-        defaultSSLContext = newContext(verifyMode = CVerifyNone)
+proc getDefaultSSL(): SSLContext =
+  result = defaultSslContext
+  when defined(ssl):
+    if result == nil:
+      defaultSSLContext = newContext(verifyMode = CVerifyNone)
       result = defaultSSLContext
-    result
+      doAssert result != nil, "failure to initialize the SSL context"
 
 proc newProxy*(url: string, auth = ""): Proxy =
   ## Constructs a new ``TProxy`` object.
@@ -480,9 +478,9 @@ proc format(p: MultipartData): tuple[contentType, body: string] =
   result.body.add("--" & bound & "--\c\L")
 
 proc request*(url: string, httpMethod: string, extraHeaders = "",
-              body = "", sslContext = defaultSSLContext, timeout = -1,
+              body = "", sslContext = getDefaultSSL(), timeout = -1,
               userAgent = defUserAgent, proxy: Proxy = nil): Response
-              {.deprecated.} =
+              {.deprecated: "use HttpClient.request instead".} =
   ## | Requests ``url`` with the custom method string specified by the
   ## | ``httpMethod`` parameter.
   ## | Extra headers can be specified and must be separated by ``\c\L``
@@ -580,7 +578,7 @@ proc request*(url: string, httpMethod: string, extraHeaders = "",
   result = parseResponse(s, httpMethod != "HEAD", timeout)
 
 proc request*(url: string, httpMethod = HttpGET, extraHeaders = "",
-              body = "", sslContext = defaultSSLContext, timeout = -1,
+              body = "", sslContext = getDefaultSSL(), timeout = -1,
               userAgent = defUserAgent, proxy: Proxy = nil): Response
               {.deprecated.} =
   ## | Requests ``url`` with the specified ``httpMethod``.
@@ -611,7 +609,7 @@ proc getNewLocation(lastURL: string, headers: HttpHeaders): string =
     result = $parsed
 
 proc get*(url: string, extraHeaders = "", maxRedirects = 5,
-          sslContext: SSLContext = defaultSSLContext,
+          sslContext: SSLContext = getDefaultSSL(),
           timeout = -1, userAgent = defUserAgent,
           proxy: Proxy = nil): Response {.deprecated.} =
   ## | GETs the ``url`` and returns a ``Response`` object
@@ -632,7 +630,7 @@ proc get*(url: string, extraHeaders = "", maxRedirects = 5,
       lastURL = redirectTo
 
 proc getContent*(url: string, extraHeaders = "", maxRedirects = 5,
-                 sslContext: SSLContext = defaultSSLContext,
+                 sslContext: SSLContext = getDefaultSSL(),
                  timeout = -1, userAgent = defUserAgent,
                  proxy: Proxy = nil): string {.deprecated.} =
   ## | GETs the body and returns it as a string.
@@ -651,7 +649,7 @@ proc getContent*(url: string, extraHeaders = "", maxRedirects = 5,
 
 proc post*(url: string, extraHeaders = "", body = "",
            maxRedirects = 5,
-           sslContext: SSLContext = defaultSSLContext,
+           sslContext: SSLContext = getDefaultSSL(),
            timeout = -1, userAgent = defUserAgent,
            proxy: Proxy = nil,
            multipart: MultipartData = nil): Response {.deprecated.} =
@@ -694,7 +692,7 @@ proc post*(url: string, extraHeaders = "", body = "",
 
 proc postContent*(url: string, extraHeaders = "", body = "",
                   maxRedirects = 5,
-                  sslContext: SSLContext = defaultSSLContext,
+                  sslContext: SSLContext = getDefaultSSL(),
                   timeout = -1, userAgent = defUserAgent,
                   proxy: Proxy = nil,
                   multipart: MultipartData = nil): string
@@ -717,7 +715,7 @@ proc postContent*(url: string, extraHeaders = "", body = "",
     return r.body
 
 proc downloadFile*(url: string, outputFilename: string,
-                   sslContext: SSLContext = defaultSSLContext,
+                   sslContext: SSLContext = getDefaultSSL(),
                    timeout = -1, userAgent = defUserAgent,
                    proxy: Proxy = nil) {.deprecated.} =
   ## | Downloads ``url`` and saves it to ``outputFilename``
@@ -817,7 +815,7 @@ type
   HttpClient* = HttpClientBase[Socket]
 
 proc newHttpClient*(userAgent = defUserAgent,
-    maxRedirects = 5, sslContext = defaultSslContext, proxy: Proxy = nil,
+    maxRedirects = 5, sslContext = getDefaultSSL(), proxy: Proxy = nil,
     timeout = -1): HttpClient =
   ## Creates a new HttpClient instance.
   ##
@@ -844,7 +842,7 @@ proc newHttpClient*(userAgent = defUserAgent,
   result.bodyStream = newStringStream()
   result.getBody = true
   when defined(ssl):
-    result.sslContext = contextOrDefault(sslContext)
+    result.sslContext = sslContext
 
 type
   AsyncHttpClient* = HttpClientBase[AsyncSocket]
@@ -852,7 +850,7 @@ type
 {.deprecated: [PAsyncHttpClient: AsyncHttpClient].}
 
 proc newAsyncHttpClient*(userAgent = defUserAgent,
-    maxRedirects = 5, sslContext = defaultSslContext,
+    maxRedirects = 5, sslContext = getDefaultSSL(),
     proxy: Proxy = nil): AsyncHttpClient =
   ## Creates a new AsyncHttpClient instance.
   ##
@@ -876,7 +874,7 @@ proc newAsyncHttpClient*(userAgent = defUserAgent,
   result.bodyStream = newFutureStream[string]("newAsyncHttpClient")
   result.getBody = true
   when defined(ssl):
-    result.sslContext = contextOrDefault(sslContext)
+    result.sslContext = sslContext
 
 proc close*(client: HttpClient | AsyncHttpClient) =
   ## Closes any connections held by the HTTP client.
diff --git a/lib/pure/json.nim b/lib/pure/json.nim
index 9f9339961..e7ad5bd5a 100644
--- a/lib/pure/json.nim
+++ b/lib/pure/json.nim
@@ -89,507 +89,22 @@
 ##    echo j2
 
 import
-  hashes, tables, strutils, lexbase, streams, unicode, macros
+  hashes, tables, strutils, lexbase, streams, unicode, macros, parsejson
 
 export
   tables.`$`
 
+export
+  parsejson.JsonEventKind, parsejson.JsonError, JsonParser, JsonKindError,
+  open, close, str, getInt, getFloat, kind, getColumn, getLine, getFilename,
+  errorMsg, errorMsgExpected, next, JsonParsingError, raiseParseErr
+
 when defined(nimJsonGet):
   {.pragma: deprecatedGet, deprecated.}
 else:
   {.pragma: deprecatedGet.}
 
 type
-  JsonEventKind* = enum  ## enumeration of all events that may occur when parsing
-    jsonError,           ## an error occurred during parsing
-    jsonEof,             ## end of file reached
-    jsonString,          ## a string literal
-    jsonInt,             ## an integer literal
-    jsonFloat,           ## a float literal
-    jsonTrue,            ## the value ``true``
-    jsonFalse,           ## the value ``false``
-    jsonNull,            ## the value ``null``
-    jsonObjectStart,     ## start of an object: the ``{`` token
-    jsonObjectEnd,       ## end of an object: the ``}`` token
-    jsonArrayStart,      ## start of an array: the ``[`` token
-    jsonArrayEnd         ## start of an array: the ``]`` token
-
-  TokKind = enum         # must be synchronized with TJsonEventKind!
-    tkError,
-    tkEof,
-    tkString,
-    tkInt,
-    tkFloat,
-    tkTrue,
-    tkFalse,
-    tkNull,
-    tkCurlyLe,
-    tkCurlyRi,
-    tkBracketLe,
-    tkBracketRi,
-    tkColon,
-    tkComma
-
-  JsonError* = enum        ## enumeration that lists all errors that can occur
-    errNone,               ## no error
-    errInvalidToken,       ## invalid token
-    errStringExpected,     ## string expected
-    errColonExpected,      ## ``:`` expected
-    errCommaExpected,      ## ``,`` expected
-    errBracketRiExpected,  ## ``]`` expected
-    errCurlyRiExpected,    ## ``}`` expected
-    errQuoteExpected,      ## ``"`` or ``'`` expected
-    errEOC_Expected,       ## ``*/`` expected
-    errEofExpected,        ## EOF expected
-    errExprExpected        ## expr expected
-
-  ParserState = enum
-    stateEof, stateStart, stateObject, stateArray, stateExpectArrayComma,
-    stateExpectObjectComma, stateExpectColon, stateExpectValue
-
-  JsonParser* = object of BaseLexer ## the parser object.
-    a: string
-    tok: TokKind
-    kind: JsonEventKind
-    err: JsonError
-    state: seq[ParserState]
-    filename: string
-
-  JsonKindError* = object of ValueError ## raised by the ``to`` macro if the
-                                        ## JSON kind is incorrect.
-
-const
-  errorMessages: array[JsonError, string] = [
-    "no error",
-    "invalid token",
-    "string expected",
-    "':' expected",
-    "',' expected",
-    "']' expected",
-    "'}' expected",
-    "'\"' or \"'\" expected",
-    "'*/' expected",
-    "EOF expected",
-    "expression expected"
-  ]
-  tokToStr: array[TokKind, string] = [
-    "invalid token",
-    "EOF",
-    "string literal",
-    "int literal",
-    "float literal",
-    "true",
-    "false",
-    "null",
-    "{", "}", "[", "]", ":", ","
-  ]
-
-proc open*(my: var JsonParser, input: Stream, filename: string) =
-  ## initializes the parser with an input stream. `Filename` is only used
-  ## for nice error messages.
-  lexbase.open(my, input)
-  my.filename = filename
-  my.state = @[stateStart]
-  my.kind = jsonError
-  my.a = ""
-
-proc close*(my: var JsonParser) {.inline.} =
-  ## closes the parser `my` and its associated input stream.
-  lexbase.close(my)
-
-proc str*(my: JsonParser): string {.inline.} =
-  ## returns the character data for the events: ``jsonInt``, ``jsonFloat``,
-  ## ``jsonString``
-  assert(my.kind in {jsonInt, jsonFloat, jsonString})
-  return my.a
-
-proc getInt*(my: JsonParser): BiggestInt {.inline.} =
-  ## returns the number for the event: ``jsonInt``
-  assert(my.kind == jsonInt)
-  return parseBiggestInt(my.a)
-
-proc getFloat*(my: JsonParser): float {.inline.} =
-  ## returns the number for the event: ``jsonFloat``
-  assert(my.kind == jsonFloat)
-  return parseFloat(my.a)
-
-proc kind*(my: JsonParser): JsonEventKind {.inline.} =
-  ## returns the current event type for the JSON parser
-  return my.kind
-
-proc getColumn*(my: JsonParser): int {.inline.} =
-  ## get the current column the parser has arrived at.
-  result = getColNumber(my, my.bufpos)
-
-proc getLine*(my: JsonParser): int {.inline.} =
-  ## get the current line the parser has arrived at.
-  result = my.lineNumber
-
-proc getFilename*(my: JsonParser): string {.inline.} =
-  ## get the filename of the file that the parser processes.
-  result = my.filename
-
-proc errorMsg*(my: JsonParser): string =
-  ## returns a helpful error message for the event ``jsonError``
-  assert(my.kind == jsonError)
-  result = "$1($2, $3) Error: $4" % [
-    my.filename, $getLine(my), $getColumn(my), errorMessages[my.err]]
-
-proc errorMsgExpected*(my: JsonParser, e: string): string =
-  ## returns an error message "`e` expected" in the same format as the
-  ## other error messages
-  result = "$1($2, $3) Error: $4" % [
-    my.filename, $getLine(my), $getColumn(my), e & " expected"]
-
-proc handleHexChar(c: char, x: var int): bool =
-  result = true # Success
-  case c
-  of '0'..'9': x = (x shl 4) or (ord(c) - ord('0'))
-  of 'a'..'f': x = (x shl 4) or (ord(c) - ord('a') + 10)
-  of 'A'..'F': x = (x shl 4) or (ord(c) - ord('A') + 10)
-  else: result = false # error
-
-proc parseEscapedUTF16(buf: cstring, pos: var int): int =
-  result = 0
-  #UTF-16 escape is always 4 bytes.
-  for _ in 0..3:
-    if handleHexChar(buf[pos], result):
-      inc(pos)
-    else:
-      return -1
-
-proc parseString(my: var JsonParser): TokKind =
-  result = tkString
-  var pos = my.bufpos + 1
-  var buf = my.buf
-  while true:
-    case buf[pos]
-    of '\0':
-      my.err = errQuoteExpected
-      result = tkError
-      break
-    of '"':
-      inc(pos)
-      break
-    of '\\':
-      case buf[pos+1]
-      of '\\', '"', '\'', '/':
-        add(my.a, buf[pos+1])
-        inc(pos, 2)
-      of 'b':
-        add(my.a, '\b')
-        inc(pos, 2)
-      of 'f':
-        add(my.a, '\f')
-        inc(pos, 2)
-      of 'n':
-        add(my.a, '\L')
-        inc(pos, 2)
-      of 'r':
-        add(my.a, '\C')
-        inc(pos, 2)
-      of 't':
-        add(my.a, '\t')
-        inc(pos, 2)
-      of 'u':
-        inc(pos, 2)
-        var r = parseEscapedUTF16(buf, pos)
-        if r < 0:
-          my.err = errInvalidToken
-          break
-        # Deal with surrogates
-        if (r and 0xfc00) == 0xd800:
-          if buf[pos] & buf[pos+1] != "\\u":
-            my.err = errInvalidToken
-            break
-          inc(pos, 2)
-          var s = parseEscapedUTF16(buf, pos)
-          if (s and 0xfc00) == 0xdc00 and s > 0:
-            r = 0x10000 + (((r - 0xd800) shl 10) or (s - 0xdc00))
-          else:
-            my.err = errInvalidToken
-            break
-        add(my.a, toUTF8(Rune(r)))
-      else:
-        # don't bother with the error
-        add(my.a, buf[pos])
-        inc(pos)
-    of '\c':
-      pos = lexbase.handleCR(my, pos)
-      buf = my.buf
-      add(my.a, '\c')
-    of '\L':
-      pos = lexbase.handleLF(my, pos)
-      buf = my.buf
-      add(my.a, '\L')
-    else:
-      add(my.a, buf[pos])
-      inc(pos)
-  my.bufpos = pos # store back
-
-proc skip(my: var JsonParser) =
-  var pos = my.bufpos
-  var buf = my.buf
-  while true:
-    case buf[pos]
-    of '/':
-      if buf[pos+1] == '/':
-        # skip line comment:
-        inc(pos, 2)
-        while true:
-          case buf[pos]
-          of '\0':
-            break
-          of '\c':
-            pos = lexbase.handleCR(my, pos)
-            buf = my.buf
-            break
-          of '\L':
-            pos = lexbase.handleLF(my, pos)
-            buf = my.buf
-            break
-          else:
-            inc(pos)
-      elif buf[pos+1] == '*':
-        # skip long comment:
-        inc(pos, 2)
-        while true:
-          case buf[pos]
-          of '\0':
-            my.err = errEOC_Expected
-            break
-          of '\c':
-            pos = lexbase.handleCR(my, pos)
-            buf = my.buf
-          of '\L':
-            pos = lexbase.handleLF(my, pos)
-            buf = my.buf
-          of '*':
-            inc(pos)
-            if buf[pos] == '/':
-              inc(pos)
-              break
-          else:
-            inc(pos)
-      else:
-        break
-    of ' ', '\t':
-      inc(pos)
-    of '\c':
-      pos = lexbase.handleCR(my, pos)
-      buf = my.buf
-    of '\L':
-      pos = lexbase.handleLF(my, pos)
-      buf = my.buf
-    else:
-      break
-  my.bufpos = pos
-
-proc parseNumber(my: var JsonParser) =
-  var pos = my.bufpos
-  var buf = my.buf
-  if buf[pos] == '-':
-    add(my.a, '-')
-    inc(pos)
-  if buf[pos] == '.':
-    add(my.a, "0.")
-    inc(pos)
-  else:
-    while buf[pos] in Digits:
-      add(my.a, buf[pos])
-      inc(pos)
-    if buf[pos] == '.':
-      add(my.a, '.')
-      inc(pos)
-  # digits after the dot:
-  while buf[pos] in Digits:
-    add(my.a, buf[pos])
-    inc(pos)
-  if buf[pos] in {'E', 'e'}:
-    add(my.a, buf[pos])
-    inc(pos)
-    if buf[pos] in {'+', '-'}:
-      add(my.a, buf[pos])
-      inc(pos)
-    while buf[pos] in Digits:
-      add(my.a, buf[pos])
-      inc(pos)
-  my.bufpos = pos
-
-proc parseName(my: var JsonParser) =
-  var pos = my.bufpos
-  var buf = my.buf
-  if buf[pos] in IdentStartChars:
-    while buf[pos] in IdentChars:
-      add(my.a, buf[pos])
-      inc(pos)
-  my.bufpos = pos
-
-proc getTok(my: var JsonParser): TokKind =
-  setLen(my.a, 0)
-  skip(my) # skip whitespace, comments
-  case my.buf[my.bufpos]
-  of '-', '.', '0'..'9':
-    parseNumber(my)
-    if {'.', 'e', 'E'} in my.a:
-      result = tkFloat
-    else:
-      result = tkInt
-  of '"':
-    result = parseString(my)
-  of '[':
-    inc(my.bufpos)
-    result = tkBracketLe
-  of '{':
-    inc(my.bufpos)
-    result = tkCurlyLe
-  of ']':
-    inc(my.bufpos)
-    result = tkBracketRi
-  of '}':
-    inc(my.bufpos)
-    result = tkCurlyRi
-  of ',':
-    inc(my.bufpos)
-    result = tkComma
-  of ':':
-    inc(my.bufpos)
-    result = tkColon
-  of '\0':
-    result = tkEof
-  of 'a'..'z', 'A'..'Z', '_':
-    parseName(my)
-    case my.a
-    of "null": result = tkNull
-    of "true": result = tkTrue
-    of "false": result = tkFalse
-    else: result = tkError
-  else:
-    inc(my.bufpos)
-    result = tkError
-  my.tok = result
-
-proc next*(my: var JsonParser) =
-  ## retrieves the first/next event. This controls the parser.
-  var tk = getTok(my)
-  var i = my.state.len-1
-  # the following code is a state machine. If we had proper coroutines,
-  # the code could be much simpler.
-  case my.state[i]
-  of stateEof:
-    if tk == tkEof:
-      my.kind = jsonEof
-    else:
-      my.kind = jsonError
-      my.err = errEofExpected
-  of stateStart:
-    # tokens allowed?
-    case tk
-    of tkString, tkInt, tkFloat, tkTrue, tkFalse, tkNull:
-      my.state[i] = stateEof # expect EOF next!
-      my.kind = JsonEventKind(ord(tk))
-    of tkBracketLe:
-      my.state.add(stateArray) # we expect any
-      my.kind = jsonArrayStart
-    of tkCurlyLe:
-      my.state.add(stateObject)
-      my.kind = jsonObjectStart
-    of tkEof:
-      my.kind = jsonEof
-    else:
-      my.kind = jsonError
-      my.err = errEofExpected
-  of stateObject:
-    case tk
-    of tkString, tkInt, tkFloat, tkTrue, tkFalse, tkNull:
-      my.state.add(stateExpectColon)
-      my.kind = JsonEventKind(ord(tk))
-    of tkBracketLe:
-      my.state.add(stateExpectColon)
-      my.state.add(stateArray)
-      my.kind = jsonArrayStart
-    of tkCurlyLe:
-      my.state.add(stateExpectColon)
-      my.state.add(stateObject)
-      my.kind = jsonObjectStart
-    of tkCurlyRi:
-      my.kind = jsonObjectEnd
-      discard my.state.pop()
-    else:
-      my.kind = jsonError
-      my.err = errCurlyRiExpected
-  of stateArray:
-    case tk
-    of tkString, tkInt, tkFloat, tkTrue, tkFalse, tkNull:
-      my.state.add(stateExpectArrayComma) # expect value next!
-      my.kind = JsonEventKind(ord(tk))
-    of tkBracketLe:
-      my.state.add(stateExpectArrayComma)
-      my.state.add(stateArray)
-      my.kind = jsonArrayStart
-    of tkCurlyLe:
-      my.state.add(stateExpectArrayComma)
-      my.state.add(stateObject)
-      my.kind = jsonObjectStart
-    of tkBracketRi:
-      my.kind = jsonArrayEnd
-      discard my.state.pop()
-    else:
-      my.kind = jsonError
-      my.err = errBracketRiExpected
-  of stateExpectArrayComma:
-    case tk
-    of tkComma:
-      discard my.state.pop()
-      next(my)
-    of tkBracketRi:
-      my.kind = jsonArrayEnd
-      discard my.state.pop() # pop stateExpectArrayComma
-      discard my.state.pop() # pop stateArray
-    else:
-      my.kind = jsonError
-      my.err = errBracketRiExpected
-  of stateExpectObjectComma:
-    case tk
-    of tkComma:
-      discard my.state.pop()
-      next(my)
-    of tkCurlyRi:
-      my.kind = jsonObjectEnd
-      discard my.state.pop() # pop stateExpectObjectComma
-      discard my.state.pop() # pop stateObject
-    else:
-      my.kind = jsonError
-      my.err = errCurlyRiExpected
-  of stateExpectColon:
-    case tk
-    of tkColon:
-      my.state[i] = stateExpectValue
-      next(my)
-    else:
-      my.kind = jsonError
-      my.err = errColonExpected
-  of stateExpectValue:
-    case tk
-    of tkString, tkInt, tkFloat, tkTrue, tkFalse, tkNull:
-      my.state[i] = stateExpectObjectComma
-      my.kind = JsonEventKind(ord(tk))
-    of tkBracketLe:
-      my.state[i] = stateExpectObjectComma
-      my.state.add(stateArray)
-      my.kind = jsonArrayStart
-    of tkCurlyLe:
-      my.state[i] = stateExpectObjectComma
-      my.state.add(stateObject)
-      my.kind = jsonObjectStart
-    else:
-      my.kind = jsonError
-      my.err = errExprExpected
-
-
-# ------------- higher level interface ---------------------------------------
-
-type
   JsonNodeKind* = enum ## possible JSON node types
     JNull,
     JBool,
@@ -617,12 +132,6 @@ type
     of JArray:
       elems*: seq[JsonNode]
 
-  JsonParsingError* = object of ValueError ## is raised for a JSON error
-
-proc raiseParseErr*(p: JsonParser, msg: string) {.noinline, noreturn.} =
-  ## raises an `EJsonParsingError` exception.
-  raise newException(JsonParsingError, errorMsgExpected(p, msg))
-
 proc newJString*(s: string): JsonNode =
   ## Creates a new `JString JsonNode`.
   new(result)
@@ -1000,7 +509,7 @@ proc delete*(obj: JsonNode, key: string) =
   ## Deletes ``obj[key]``.
   assert(obj.kind == JObject)
   if not obj.fields.hasKey(key):
-    raise newException(IndexError, "key not in object")
+    raise newException(KeyError, "key not in object")
   obj.fields.del(key)
 
 proc copy*(p: JsonNode): JsonNode =
@@ -1049,6 +558,8 @@ proc escapeJson*(s: string; result: var string) =
     of '\t': result.add("\\t")
     of '\r': result.add("\\r")
     of '"': result.add("\\\"")
+    of '\0'..'\7': result.add("\\u000" & $ord(c))
+    of '\14'..'\31': result.add("\\u00" & $ord(c))
     of '\\': result.add("\\\\")
     else: result.add(c)
   result.add("\"")
@@ -1194,10 +705,6 @@ iterator mpairs*(node: var JsonNode): tuple[key: string, val: var JsonNode] =
   for key, val in mpairs(node.fields):
     yield (key, val)
 
-proc eat(p: var JsonParser, tok: TokKind) =
-  if p.tok == tok: discard getTok(p)
-  else: raiseParseErr(p, tokToStr[tok])
-
 proc parseJson(p: var JsonParser): JsonNode =
   ## Parses JSON from a JSON Parser `p`.
   case p.tok
@@ -1253,10 +760,12 @@ when not defined(js):
     ## If `s` contains extra data, it will raise `JsonParsingError`.
     var p: JsonParser
     p.open(s, filename)
-    defer: p.close()
-    discard getTok(p) # read first token
-    result = p.parseJson()
-    eat(p, tkEof) # check if there is no extra data
+    try:
+      discard getTok(p) # read first token
+      result = p.parseJson()
+      eat(p, tkEof) # check if there is no extra data
+    finally:
+      p.close()
 
   proc parseJson*(buffer: string): JsonNode =
     ## Parses JSON from `buffer`.
@@ -1989,18 +1498,18 @@ when isMainModule:
   # Bounds checking
   try:
     let a = testJson["a"][9]
-    doAssert(false, "EInvalidIndex not thrown")
+    doAssert(false, "IndexError not thrown")
   except IndexError:
     discard
   try:
     let a = testJson["a"][-1]
-    doAssert(false, "EInvalidIndex not thrown")
+    doAssert(false, "IndexError not thrown")
   except IndexError:
     discard
   try:
     doAssert(testJson["a"][0].num == 1, "Index doesn't correspond to its value")
   except:
-    doAssert(false, "EInvalidIndex thrown for valid index")
+    doAssert(false, "IndexError thrown for valid index")
 
   doAssert(testJson{"b"}.str=="asd", "Couldn't fetch a singly nested key with {}")
   doAssert(isNil(testJson{"nonexistent"}), "Non-existent keys should return nil")
@@ -2074,6 +1583,7 @@ when isMainModule:
     doAssert(parsed2{"repository", "description"}.str=="IRC Library for Haskell", "Couldn't fetch via multiply nested key using {}")
 
   doAssert escapeJson("\10Foo🎃barÄ") == "\"\\nFoo🎃barÄ\""
+  doAssert escapeJson("\0\7\20") == "\"\\u0000\\u0007\\u0020\"" # for #7887
 
   # Test with extra data
   when not defined(js):
diff --git a/lib/pure/math.nim b/lib/pure/math.nim
index 5f3240e00..8ea8ee203 100644
--- a/lib/pure/math.nim
+++ b/lib/pure/math.nim
@@ -21,6 +21,8 @@ include "system/inclrtl"
 {.push debugger:off .} # the user does not want to trace a part
                        # of the standard library!
 
+import bitops
+
 proc binom*(n, k: int): int {.noSideEffect.} =
   ## Computes the binomial coefficient
   if k <= 0: return 1
@@ -41,7 +43,7 @@ proc fac*(n: int): int =
       createFactTable[13]()
     else:
       createFactTable[21]()
-  assert(n > 0, $n & " must not be negative.")
+  assert(n >= 0, $n & " must not be negative.")
   assert(n < factTable.len, $n & " is too large to look up in the table")
   factTable[n]
 
@@ -127,8 +129,14 @@ proc sum*[T](x: openArray[T]): T {.noSideEffect.} =
   ## If `x` is empty, 0 is returned.
   for i in items(x): result = result + i
 
+proc prod*[T](x: openArray[T]): T {.noSideEffect.} =
+  ## Computes the product of the elements in ``x``.
+  ## If ``x`` is empty, 1 is returned.
+  result = 1.T
+  for i in items(x): result = result * i
+
 {.push noSideEffect.}
-when not defined(JS):
+when not defined(JS): # C
   proc sqrt*(x: float32): float32 {.importc: "sqrtf", header: "<math.h>".}
   proc sqrt*(x: float64): float64 {.importc: "sqrt", header: "<math.h>".}
     ## Computes the square root of `x`.
@@ -142,12 +150,33 @@ when not defined(JS):
   proc log10*(x: float32): float32 {.importc: "log10f", header: "<math.h>".}
   proc log10*(x: float64): float64 {.importc: "log10", header: "<math.h>".}
     ## Computes the common logarithm (base 10) of `x`
-  proc log2*[T: float32|float64](x: T): T = return ln(x) / ln(2.0)
+  proc log2*(x: float32): float32 {.importc: "log2f", header: "<math.h>".}
+  proc log2*(x: float64): float64 {.importc: "log2", header: "<math.h>".}
     ## Computes the binary logarithm (base 2) of `x`
   proc exp*(x: float32): float32 {.importc: "expf", header: "<math.h>".}
   proc exp*(x: float64): float64 {.importc: "exp", header: "<math.h>".}
     ## Computes the exponential function of `x` (pow(E, x))
 
+  proc sin*(x: float32): float32 {.importc: "sinf", header: "<math.h>".}
+  proc sin*(x: float64): float64 {.importc: "sin", header: "<math.h>".}
+    ## Computes the sine of `x`
+  proc cos*(x: float32): float32 {.importc: "cosf", header: "<math.h>".}
+  proc cos*(x: float64): float64 {.importc: "cos", header: "<math.h>".}
+    ## Computes the cosine of `x`
+  proc tan*(x: float32): float32 {.importc: "tanf", header: "<math.h>".}
+  proc tan*(x: float64): float64 {.importc: "tan", header: "<math.h>".}
+    ## Computes the tangent of `x`
+
+  proc sinh*(x: float32): float32 {.importc: "sinhf", header: "<math.h>".}
+  proc sinh*(x: float64): float64 {.importc: "sinh", header: "<math.h>".}
+    ## Computes the hyperbolic sine of `x`
+  proc cosh*(x: float32): float32 {.importc: "coshf", header: "<math.h>".}
+  proc cosh*(x: float64): float64 {.importc: "cosh", header: "<math.h>".}
+    ## Computes the hyperbolic cosine of `x`
+  proc tanh*(x: float32): float32 {.importc: "tanhf", header: "<math.h>".}
+  proc tanh*(x: float64): float64 {.importc: "tanh", header: "<math.h>".}
+    ## Computes the hyperbolic tangent of `x`
+
   proc arccos*(x: float32): float32 {.importc: "acosf", header: "<math.h>".}
   proc arccos*(x: float64): float64 {.importc: "acos", header: "<math.h>".}
     ## Computes the arc cosine of `x`
@@ -164,33 +193,80 @@ when not defined(JS):
     ## results even when the resulting angle is near pi/2 or -pi/2
     ## (`x` near 0).
 
-  proc cos*(x: float32): float32 {.importc: "cosf", header: "<math.h>".}
-  proc cos*(x: float64): float64 {.importc: "cos", header: "<math.h>".}
-    ## Computes the cosine of `x`
+  proc arcsinh*(x: float32): float32 {.importc: "asinhf", header: "<math.h>".}
+  proc arcsinh*(x: float64): float64 {.importc: "asinh", header: "<math.h>".}
+    ## Computes the inverse hyperbolic sine of `x`
+  proc arccosh*(x: float32): float32 {.importc: "acoshf", header: "<math.h>".}
+  proc arccosh*(x: float64): float64 {.importc: "acosh", header: "<math.h>".}
+    ## Computes the inverse hyperbolic cosine of `x`
+  proc arctanh*(x: float32): float32 {.importc: "atanhf", header: "<math.h>".}
+  proc arctanh*(x: float64): float64 {.importc: "atanh", header: "<math.h>".}
+    ## Computes the inverse hyperbolic tangent of `x`
+
+else: # JS
+  proc sqrt*(x: float32): float32 {.importc: "Math.sqrt", nodecl.}
+  proc sqrt*(x: float64): float64 {.importc: "Math.sqrt", nodecl.}
 
-  proc cosh*(x: float32): float32 {.importc: "coshf", header: "<math.h>".}
-  proc cosh*(x: float64): float64 {.importc: "cosh", header: "<math.h>".}
-    ## Computes the hyperbolic cosine of `x`
+  proc ln*(x: float32): float32 {.importc: "Math.log", nodecl.}
+  proc ln*(x: float64): float64 {.importc: "Math.log", nodecl.}
+  proc log10*(x: float32): float32 {.importc: "Math.log10", nodecl.}
+  proc log10*(x: float64): float64 {.importc: "Math.log10", nodecl.}
+  proc log2*(x: float32): float32 {.importc: "Math.log2", nodecl.}
+  proc log2*(x: float64): float64 {.importc: "Math.log2", nodecl.}
+  proc exp*(x: float32): float32 {.importc: "Math.exp", nodecl.}
+  proc exp*(x: float64): float64 {.importc: "Math.exp", nodecl.}
 
+  proc sin*[T: float32|float64](x: T): T {.importc: "Math.sin", nodecl.}
+  proc cos*[T: float32|float64](x: T): T {.importc: "Math.cos", nodecl.}
+  proc tan*[T: float32|float64](x: T): T {.importc: "Math.tan", nodecl.}
+
+  proc sinh*[T: float32|float64](x: T): T {.importc: "Math.sinh", nodecl.}
+  proc cosh*[T: float32|float64](x: T): T {.importc: "Math.cosh", nodecl.}
+  proc tanh*[T: float32|float64](x: T): T {.importc: "Math.tanh", nodecl.}
+
+  proc arcsin*[T: float32|float64](x: T): T {.importc: "Math.asin", nodecl.}
+  proc arccos*[T: float32|float64](x: T): T {.importc: "Math.acos", nodecl.}
+  proc arctan*[T: float32|float64](x: T): T {.importc: "Math.atan", nodecl.}
+  proc arctan2*[T: float32|float64](y, x: T): T {.importC: "Math.atan2", nodecl.}
+
+  proc arcsinh*[T: float32|float64](x: T): T {.importc: "Math.asinh", nodecl.}
+  proc arccosh*[T: float32|float64](x: T): T {.importc: "Math.acosh", nodecl.}
+  proc arctanh*[T: float32|float64](x: T): T {.importc: "Math.atanh", nodecl.}
+
+proc cot*[T: float32|float64](x: T): T = 1.0 / tan(x)
+  ## Computes the cotangent of `x`
+proc sec*[T: float32|float64](x: T): T = 1.0 / cos(x)
+  ## Computes the secant of `x`.
+proc csc*[T: float32|float64](x: T): T = 1.0 / sin(x)
+  ## Computes the cosecant of `x`
+
+proc coth*[T: float32|float64](x: T): T = 1.0 / tanh(x)
+  ## Computes the hyperbolic cotangent of `x`
+proc sech*[T: float32|float64](x: T): T = 1.0 / cosh(x)
+  ## Computes the hyperbolic secant of `x`
+proc csch*[T: float32|float64](x: T): T = 1.0 / sinh(x)
+  ## Computes the hyperbolic cosecant of `x`
+
+proc arccot*[T: float32|float64](x: T): T = arctan(1.0 / x)
+  ## Computes the inverse cotangent of `x`
+proc arcsec*[T: float32|float64](x: T): T = arccos(1.0 / x)
+  ## Computes the inverse secant of `x`
+proc arccsc*[T: float32|float64](x: T): T = arcsin(1.0 / x)
+  ## Computes the inverse cosecant of `x`
+
+proc arccoth*[T: float32|float64](x: T): T = arctanh(1.0 / x)
+  ## Computes the inverse hyperbolic cotangent of `x`
+proc arcsech*[T: float32|float64](x: T): T = arccosh(1.0 / x)
+  ## Computes the inverse hyperbolic secant of `x`
+proc arccsch*[T: float32|float64](x: T): T = arcsinh(1.0 / x)
+  ## Computes the inverse hyperbolic cosecant of `x`
+
+when not defined(JS): # C
   proc hypot*(x, y: float32): float32 {.importc: "hypotf", header: "<math.h>".}
   proc hypot*(x, y: float64): float64 {.importc: "hypot", header: "<math.h>".}
     ## Computes the hypotenuse of a right-angle triangle with `x` and
     ## `y` as its base and height. Equivalent to ``sqrt(x*x + y*y)``.
 
-  proc sinh*(x: float32): float32 {.importc: "sinhf", header: "<math.h>".}
-  proc sinh*(x: float64): float64 {.importc: "sinh", header: "<math.h>".}
-    ## Computes the hyperbolic sine of `x`
-  proc sin*(x: float32): float32 {.importc: "sinf", header: "<math.h>".}
-  proc sin*(x: float64): float64 {.importc: "sin", header: "<math.h>".}
-    ## Computes the sine of `x`
-
-  proc tan*(x: float32): float32 {.importc: "tanf", header: "<math.h>".}
-  proc tan*(x: float64): float64 {.importc: "tan", header: "<math.h>".}
-    ## Computes the tangent of `x`
-  proc tanh*(x: float32): float32 {.importc: "tanhf", header: "<math.h>".}
-  proc tanh*(x: float64): float64 {.importc: "tanh", header: "<math.h>".}
-    ## Computes the hyperbolic tangent of `x`
-
   proc pow*(x, y: float32): float32 {.importc: "powf", header: "<math.h>".}
   proc pow*(x, y: float64): float64 {.importc: "pow", header: "<math.h>".}
     ## computes x to power raised of y.
@@ -204,12 +280,18 @@ when not defined(JS):
   proc erfc*(x: float64): float64 {.importc: "erfc", header: "<math.h>".}
     ## The complementary error function
 
+  proc gamma*(x: float32): float32 {.importc: "tgammaf", header: "<math.h>".}
+  proc gamma*(x: float64): float64 {.importc: "tgamma", header: "<math.h>".}
+    ## The gamma function
+  proc tgamma*(x: float32): float32
+    {.deprecated: "use gamma instead", importc: "tgammaf", header: "<math.h>".}
+  proc tgamma*(x: float64): float64
+    {.deprecated: "use gamma instead", importc: "tgamma", header: "<math.h>".}
+    ## The gamma function
+    ## **Deprecated since version 0.19.0**: Use ``gamma`` instead.
   proc lgamma*(x: float32): float32 {.importc: "lgammaf", header: "<math.h>".}
   proc lgamma*(x: float64): float64 {.importc: "lgamma", header: "<math.h>".}
     ## Natural log of the gamma function
-  proc tgamma*(x: float32): float32 {.importc: "tgammaf", header: "<math.h>".}
-  proc tgamma*(x: float64): float64 {.importc: "tgamma", header: "<math.h>".}
-    ## The gamma function
 
   proc floor*(x: float32): float32 {.importc: "floorf", header: "<math.h>".}
   proc floor*(x: float64): float64 {.importc: "floor", header: "<math.h>".}
@@ -293,57 +375,31 @@ when not defined(JS):
       ## .. code-block:: nim
       ##  echo trunc(PI) # 3.0
 
-  proc fmod*(x, y: float32): float32 {.importc: "fmodf", header: "<math.h>".}
-  proc fmod*(x, y: float64): float64 {.importc: "fmod", header: "<math.h>".}
+  proc fmod*(x, y: float32): float32 {.deprecated, importc: "fmodf", header: "<math.h>".}
+  proc fmod*(x, y: float64): float64 {.deprecated, importc: "fmod", header: "<math.h>".}
     ## Computes the remainder of `x` divided by `y`
     ##
     ## .. code-block:: nim
     ##  echo fmod(-2.5, 0.3) ## -0.1
 
-else:
-  proc trunc*(x: float32): float32 {.importc: "Math.trunc", nodecl.}
-  proc trunc*(x: float64): float64 {.importc: "Math.trunc", nodecl.}
+  proc `mod`*(x, y: float32): float32 {.importc: "fmodf", header: "<math.h>".}
+  proc `mod`*(x, y: float64): float64 {.importc: "fmod", header: "<math.h>".}
+    ## Computes the modulo operation for float operators.
+else: # JS
+  proc hypot*[T: float32|float64](x, y: T): T = return sqrt(x*x + y*y)
+  proc pow*(x, y: float32): float32 {.importC: "Math.pow", nodecl.}
+  proc pow*(x, y: float64): float64 {.importc: "Math.pow", nodecl.}
   proc floor*(x: float32): float32 {.importc: "Math.floor", nodecl.}
   proc floor*(x: float64): float64 {.importc: "Math.floor", nodecl.}
   proc ceil*(x: float32): float32 {.importc: "Math.ceil", nodecl.}
   proc ceil*(x: float64): float64 {.importc: "Math.ceil", nodecl.}
-
-  proc sqrt*(x: float32): float32 {.importc: "Math.sqrt", nodecl.}
-  proc sqrt*(x: float64): float64 {.importc: "Math.sqrt", nodecl.}
-  proc ln*(x: float32): float32 {.importc: "Math.log", nodecl.}
-  proc ln*(x: float64): float64 {.importc: "Math.log", nodecl.}
-  proc log10*[T: float32|float64](x: T): T = return ln(x) / ln(10.0)
-  proc log2*[T: float32|float64](x: T): T = return ln(x) / ln(2.0)
-
-  proc exp*(x: float32): float32 {.importc: "Math.exp", nodecl.}
-  proc exp*(x: float64): float64 {.importc: "Math.exp", nodecl.}
   proc round0(x: float): float {.importc: "Math.round", nodecl.}
+  proc trunc*(x: float32): float32 {.importc: "Math.trunc", nodecl.}
+  proc trunc*(x: float64): float64 {.importc: "Math.trunc", nodecl.}
 
-  proc pow*(x, y: float32): float32 {.importC: "Math.pow", nodecl.}
-  proc pow*(x, y: float64): float64 {.importc: "Math.pow", nodecl.}
-
-  proc arccos*(x: float32): float32 {.importc: "Math.acos", nodecl.}
-  proc arccos*(x: float64): float64 {.importc: "Math.acos", nodecl.}
-  proc arcsin*(x: float32): float32 {.importc: "Math.asin", nodecl.}
-  proc arcsin*(x: float64): float64 {.importc: "Math.asin", nodecl.}
-  proc arctan*(x: float32): float32 {.importc: "Math.atan", nodecl.}
-  proc arctan*(x: float64): float64 {.importc: "Math.atan", nodecl.}
-  proc arctan2*(y, x: float32): float32 {.importC: "Math.atan2", nodecl.}
-  proc arctan2*(y, x: float64): float64 {.importc: "Math.atan2", nodecl.}
-
-  proc cos*(x: float32): float32 {.importc: "Math.cos", nodecl.}
-  proc cos*(x: float64): float64 {.importc: "Math.cos", nodecl.}
-  proc cosh*(x: float32): float32 = return (exp(x)+exp(-x))*0.5
-  proc cosh*(x: float64): float64 = return (exp(x)+exp(-x))*0.5
-  proc hypot*[T: float32|float64](x, y: T): T = return sqrt(x*x + y*y)
-  proc sinh*[T: float32|float64](x: T): T = return (exp(x)-exp(-x))*0.5
-  proc sin*(x: float32): float32 {.importc: "Math.sin", nodecl.}
-  proc sin*(x: float64): float64 {.importc: "Math.sin", nodecl.}
-  proc tan*(x: float32): float32 {.importc: "Math.tan", nodecl.}
-  proc tan*(x: float64): float64 {.importc: "Math.tan", nodecl.}
-  proc tanh*[T: float32|float64](x: T): T =
-    var y = exp(2.0*x)
-    return (y-1.0)/(y+1.0)
+  proc `mod`*(x, y: float32): float32 {.importcpp: "# % #".}
+  proc `mod`*(x, y: float64): float64 {.importcpp: "# % #".}
+  ## Computes the modulo operation for float operators.
 
 proc round*[T: float32|float64](x: T, places: int = 0): T =
   ## Round a floating point number.
@@ -360,6 +416,21 @@ proc round*[T: float32|float64](x: T, places: int = 0): T =
     var mult = pow(10.0, places.T)
     result = round0(x*mult)/mult
 
+proc floorDiv*[T: SomeInteger](x, y: T): T =
+  ## Floor division is conceptually defined as ``floor(x / y)``.
+  ## This is different from the ``div`` operator, which is defined
+  ## as ``trunc(x / y)``. That is, ``div`` rounds towards ``0`` and ``floorDiv``
+  ## rounds down.
+  result = x div y
+  let r = x mod y
+  if (r > 0 and y < 0) or (r < 0 and y > 0): result.dec 1
+
+proc floorMod*[T: SomeNumber](x, y: T): T =
+  ## Floor modulus is conceptually defined as ``x - (floorDiv(x, y) * y).
+  ## This proc behaves the same as the ``%`` operator in python.
+  result = x mod y
+  if (result > 0 and y < 0) or (result < 0 and y > 0): result += y
+
 when not defined(JS):
   proc c_frexp*(x: float32, exponent: var int32): float32 {.
     importc: "frexp", header: "<math.h>".}
@@ -424,15 +495,6 @@ proc sgn*[T: SomeNumber](x: T): int {.inline.} =
   ## `NaN`.
   ord(T(0) < x) - ord(x < T(0))
 
-proc `mod`*[T: float32|float64](x, y: T): T =
-  ## Computes the modulo operation for float operators. Equivalent
-  ## to ``x - y * floor(x/y)``. Note that the remainder will always
-  ## have the same sign as the divisor.
-  ##
-  ## .. code-block:: nim
-  ##  echo (4.0 mod -3.1) # -2.2
-  result = if y == 0.0: x else: x - y * (x/y).floor
-
 {.pop.}
 {.pop.}
 
@@ -455,16 +517,42 @@ proc `^`*[T](x: T, y: Natural): T =
     x *= x
 
 proc gcd*[T](x, y: T): T =
-  ## Computes the greatest common divisor of ``x`` and ``y``.
+  ## Computes the greatest common (positive) divisor of ``x`` and ``y``.
   ## Note that for floats, the result cannot always be interpreted as
   ## "greatest decimal `z` such that ``z*N == x and z*M == y``
   ## where N and M are positive integers."
-  var (x,y) = (x,y)
+  var (x, y) = (x, y)
   while y != 0:
     x = x mod y
     swap x, y
   abs x
 
+proc gcd*(x, y: SomeInteger): SomeInteger =
+  ## Computes the greatest common (positive) divisor of ``x`` and ``y``.
+  ## Using binary GCD (aka Stein's) algorithm.
+  when x is SomeSignedInt:
+    var x = abs(x)
+  else:
+    var x = x
+  when y is SomeSignedInt:
+    var y = abs(y)
+  else:
+    var y = y
+
+  if x == 0:
+    return y
+  if y == 0:
+    return x
+
+  let shift = countTrailingZeroBits(x or y)
+  y = y shr countTrailingZeroBits(y)
+  while x != 0:
+    x = x shr countTrailingZeroBits(x)
+    if y > x:
+      swap y, x
+    x -= y
+  y shl shift
+
 proc lcm*[T](x, y: T): T =
   ## Computes the least common multiple of ``x`` and ``y``.
   x div gcd(x, y) * y
@@ -475,6 +563,7 @@ when isMainModule and not defined(JS):
     return sqrt(num)
 
   # check gamma function
+  assert(gamma(5.0) == 24.0) # 4!
   assert($tgamma(5.0) == $24.0) # 4!
   assert(lgamma(1.0) == 0.0) # ln(1.0) == 0.0
   assert(erf(6.0) > erf(5.0))
@@ -484,6 +573,12 @@ when isMainModule:
   # Function for approximate comparison of floats
   proc `==~`(x, y: float): bool = (abs(x-y) < 1e-9)
 
+  block: # prod
+    doAssert prod([1, 2, 3, 4]) == 24
+    doAssert prod([1.5, 3.4]) == 5.1
+    let x: seq[float] = @[]
+    doAssert prod(x) == 1.0
+
   block: # round() tests
     # Round to 0 decimal places
     doAssert round(54.652) ==~ 55.0
@@ -560,3 +655,30 @@ when isMainModule:
     assert sgn(Inf) == 1
     assert sgn(NaN) == 0
 
+  block: # fac() tests
+    try:
+      discard fac(-1)
+    except AssertionError:
+      discard
+
+    doAssert fac(0) == 1
+    doAssert fac(1) == 1
+    doAssert fac(2) == 2
+    doAssert fac(3) == 6
+    doAssert fac(4) == 24
+
+  block: # floorMod/floorDiv
+    doAssert floorDiv(8, 3) == 2
+    doAssert floorMod(8, 3) == 2
+
+    doAssert floorDiv(8, -3) == -3
+    doAssert floorMod(8, -3) == -1
+
+    doAssert floorDiv(-8, 3) == -3
+    doAssert floorMod(-8, 3) == 1
+
+    doAssert floorDiv(-8, -3) == 2
+    doAssert floorMod(-8, -3) == -2
+
+    doAssert floorMod(8.0, -3.0) ==~ -1.0
+    doAssert floorMod(-8.5, 3.0) ==~ 0.5
diff --git a/lib/pure/net.nim b/lib/pure/net.nim
index fc04ef1af..bf5f3f57e 100644
--- a/lib/pure/net.nim
+++ b/lib/pure/net.nim
@@ -803,6 +803,7 @@ proc acceptAddr*(server: Socket, client: var Socket, address: var string,
   else:
     address = ret[1]
     client.fd = sock
+    client.domain = getSockDomain(sock)
     client.isBuffered = server.isBuffered
 
     # Handle SSL.
diff --git a/lib/pure/os.nim b/lib/pure/os.nim
index 03445a035..04afb1eff 100644
--- a/lib/pure/os.nim
+++ b/lib/pure/os.nim
@@ -23,6 +23,10 @@ when defined(windows):
   import winlean
 elif defined(posix):
   import posix
+
+  proc toTime(ts: Timespec): times.Time {.inline.} =
+    result = initTime(ts.tv_sec.int64, ts.tv_nsec.int)
+
 else:
   {.error: "OS module not ported to your operating system!".}
 
@@ -70,7 +74,8 @@ when defined(windows):
 
 proc existsFile*(filename: string): bool {.rtl, extern: "nos$1",
                                           tags: [ReadDirEffect].} =
-  ## Returns true if the file exists, false otherwise.
+  ## Returns true if `filename` exists and is a regular file or symlink.
+  ## (directories, device files, named pipes and sockets return false)
   when defined(windows):
     when useWinUnicode:
       wrapUnary(a, getFileAttributesW, filename)
@@ -139,6 +144,7 @@ proc findExe*(exe: string, followSymlinks: bool = true;
   ## is added the `ExeExts <#ExeExts>`_ file extensions if it has none.
   ## If the system supports symlinks it also resolves them until it
   ## meets the actual file. This behavior can be disabled if desired.
+  if exe.len == 0: return
   template checkCurrentDir() =
     for ext in extensions:
       result = addFileExt(exe, ext)
@@ -149,6 +155,7 @@ proc findExe*(exe: string, followSymlinks: bool = true;
     checkCurrentDir()
   let path = string(getEnv("PATH"))
   for candidate in split(path, PathSep):
+    if candidate.len == 0: continue
     when defined(windows):
       var x = (if candidate[0] == '"' and candidate[^1] == '"':
                 substr(candidate, 1, candidate.len-2) else: candidate) /
@@ -183,7 +190,7 @@ proc getLastModificationTime*(file: string): times.Time {.rtl, extern: "nos$1".}
   when defined(posix):
     var res: Stat
     if stat(file, res) < 0'i32: raiseOSError(osLastError())
-    return fromUnix(res.st_mtime.int64)
+    result = res.st_mtim.toTime
   else:
     var f: WIN32_FIND_DATA
     var h = findFirstFile(file, f)
@@ -196,7 +203,7 @@ proc getLastAccessTime*(file: string): times.Time {.rtl, extern: "nos$1".} =
   when defined(posix):
     var res: Stat
     if stat(file, res) < 0'i32: raiseOSError(osLastError())
-    return fromUnix(res.st_atime.int64)
+    result = res.st_atim.toTime
   else:
     var f: WIN32_FIND_DATA
     var h = findFirstFile(file, f)
@@ -213,7 +220,7 @@ proc getCreationTime*(file: string): times.Time {.rtl, extern: "nos$1".} =
   when defined(posix):
     var res: Stat
     if stat(file, res) < 0'i32: raiseOSError(osLastError())
-    return fromUnix(res.st_ctime.int64)
+    result = res.st_ctim.toTime
   else:
     var f: WIN32_FIND_DATA
     var h = findFirstFile(file, f)
@@ -225,10 +232,13 @@ proc fileNewer*(a, b: string): bool {.rtl, extern: "nos$1".} =
   ## Returns true if the file `a` is newer than file `b`, i.e. if `a`'s
   ## modification time is later than `b`'s.
   when defined(posix):
-    result = getLastModificationTime(a) - getLastModificationTime(b) >= DurationZero
-    # Posix's resolution sucks so, we use '>=' for posix.
+    # If we don't have access to nanosecond resolution, use '>='
+    when not StatHasNanoseconds:  
+      result = getLastModificationTime(a) >= getLastModificationTime(b)
+    else:
+      result = getLastModificationTime(a) > getLastModificationTime(b)
   else:
-    result = getLastModificationTime(a) - getLastModificationTime(b) > DurationZero
+    result = getLastModificationTime(a) > getLastModificationTime(b)
 
 proc getCurrentDir*(): string {.rtl, extern: "nos$1", tags: [].} =
   ## Returns the `current working directory`:idx:.
@@ -1491,7 +1501,7 @@ type
 
 template rawToFormalFileInfo(rawInfo, path, formalInfo): untyped =
   ## Transforms the native file info structure into the one nim uses.
-  ## 'rawInfo' is either a 'TBY_HANDLE_FILE_INFORMATION' structure on Windows,
+  ## 'rawInfo' is either a 'BY_HANDLE_FILE_INFORMATION' structure on Windows,
   ## or a 'Stat' structure on posix
   when defined(Windows):
     template merge(a, b): untyped = a or (b shl 32)
@@ -1517,7 +1527,6 @@ template rawToFormalFileInfo(rawInfo, path, formalInfo): untyped =
     if (rawInfo.dwFileAttributes and FILE_ATTRIBUTE_REPARSE_POINT) != 0'i32:
       formalInfo.kind = succ(result.kind)
 
-
   else:
     template checkAndIncludeMode(rawMode, formalMode: untyped) =
       if (rawInfo.st_mode and rawMode) != 0'i32:
@@ -1525,9 +1534,9 @@ template rawToFormalFileInfo(rawInfo, path, formalInfo): untyped =
     formalInfo.id = (rawInfo.st_dev, rawInfo.st_ino)
     formalInfo.size = rawInfo.st_size
     formalInfo.linkCount = rawInfo.st_Nlink.BiggestInt
-    formalInfo.lastAccessTime = fromUnix(rawInfo.st_atime.int64)
-    formalInfo.lastWriteTime = fromUnix(rawInfo.st_mtime.int64)
-    formalInfo.creationTime = fromUnix(rawInfo.st_ctime.int64)
+    formalInfo.lastAccessTime = rawInfo.st_atim.toTime
+    formalInfo.lastWriteTime = rawInfo.st_mtim.toTime
+    formalInfo.creationTime = rawInfo.st_ctim.toTime
 
     result.permissions = {}
     checkAndIncludeMode(S_IRUSR, fpUserRead)
@@ -1641,7 +1650,9 @@ proc setLastModificationTime*(file: string, t: times.Time) =
   ## an error.
   when defined(posix):
     let unixt = posix.Time(t.toUnix)
-    var timevals = [Timeval(tv_sec: unixt), Timeval(tv_sec: unixt)] # [last access, last modification]
+    let micro = convert(Nanoseconds, Microseconds, t.nanosecond)
+    var timevals = [Timeval(tv_sec: unixt, tv_usec: micro),
+      Timeval(tv_sec: unixt, tv_usec: micro)] # [last access, last modification]
     if utimes(file, timevals.addr) != 0: raiseOSError(osLastError())
   else:
     let h = openHandle(path = file, writeAccess = true)
@@ -1649,4 +1660,4 @@ proc setLastModificationTime*(file: string, t: times.Time) =
     var ft = t.toWinTime.toFILETIME
     let res = setFileTime(h, nil, nil, ft.addr)
     discard h.closeHandle
-    if res == 0'i32: raiseOSError(osLastError())
\ No newline at end of file
+    if res == 0'i32: raiseOSError(osLastError())
diff --git a/lib/pure/parsejson.nim b/lib/pure/parsejson.nim
new file mode 100644
index 000000000..9c53af6a6
--- /dev/null
+++ b/lib/pure/parsejson.nim
@@ -0,0 +1,535 @@
+#
+#
+#            Nim's Runtime Library
+#        (c) Copyright 2018 Nim contributors
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## This module implements a json parser. It is used
+## and exported by the ``json`` standard library
+## module, but can also be used in its own right.
+
+import
+  strutils, lexbase, streams, unicode
+
+type
+  JsonEventKind* = enum  ## enumeration of all events that may occur when parsing
+    jsonError,           ## an error occurred during parsing
+    jsonEof,             ## end of file reached
+    jsonString,          ## a string literal
+    jsonInt,             ## an integer literal
+    jsonFloat,           ## a float literal
+    jsonTrue,            ## the value ``true``
+    jsonFalse,           ## the value ``false``
+    jsonNull,            ## the value ``null``
+    jsonObjectStart,     ## start of an object: the ``{`` token
+    jsonObjectEnd,       ## end of an object: the ``}`` token
+    jsonArrayStart,      ## start of an array: the ``[`` token
+    jsonArrayEnd         ## start of an array: the ``]`` token
+
+  TokKind* = enum         # must be synchronized with TJsonEventKind!
+    tkError,
+    tkEof,
+    tkString,
+    tkInt,
+    tkFloat,
+    tkTrue,
+    tkFalse,
+    tkNull,
+    tkCurlyLe,
+    tkCurlyRi,
+    tkBracketLe,
+    tkBracketRi,
+    tkColon,
+    tkComma
+
+  JsonError* = enum        ## enumeration that lists all errors that can occur
+    errNone,               ## no error
+    errInvalidToken,       ## invalid token
+    errStringExpected,     ## string expected
+    errColonExpected,      ## ``:`` expected
+    errCommaExpected,      ## ``,`` expected
+    errBracketRiExpected,  ## ``]`` expected
+    errCurlyRiExpected,    ## ``}`` expected
+    errQuoteExpected,      ## ``"`` or ``'`` expected
+    errEOC_Expected,       ## ``*/`` expected
+    errEofExpected,        ## EOF expected
+    errExprExpected        ## expr expected
+
+  ParserState = enum
+    stateEof, stateStart, stateObject, stateArray, stateExpectArrayComma,
+    stateExpectObjectComma, stateExpectColon, stateExpectValue
+
+  JsonParser* = object of BaseLexer ## the parser object.
+    a*: string
+    tok*: TokKind
+    kind: JsonEventKind
+    err: JsonError
+    state: seq[ParserState]
+    filename: string
+    rawStringLiterals: bool
+
+  JsonKindError* = object of ValueError ## raised by the ``to`` macro if the
+                                        ## JSON kind is incorrect.
+  JsonParsingError* = object of ValueError ## is raised for a JSON error
+
+const
+  errorMessages*: array[JsonError, string] = [
+    "no error",
+    "invalid token",
+    "string expected",
+    "':' expected",
+    "',' expected",
+    "']' expected",
+    "'}' expected",
+    "'\"' or \"'\" expected",
+    "'*/' expected",
+    "EOF expected",
+    "expression expected"
+  ]
+  tokToStr: array[TokKind, string] = [
+    "invalid token",
+    "EOF",
+    "string literal",
+    "int literal",
+    "float literal",
+    "true",
+    "false",
+    "null",
+    "{", "}", "[", "]", ":", ","
+  ]
+
+proc open*(my: var JsonParser, input: Stream, filename: string;
+           rawStringLiterals = false) =
+  ## initializes the parser with an input stream. `Filename` is only used
+  ## for nice error messages. If `rawStringLiterals` is true, string literals
+  ## are kepts with their surrounding quotes and escape sequences in them are
+  ## left untouched too.
+  lexbase.open(my, input)
+  my.filename = filename
+  my.state = @[stateStart]
+  my.kind = jsonError
+  my.a = ""
+  my.rawStringLiterals = rawStringLiterals
+
+proc close*(my: var JsonParser) {.inline.} =
+  ## closes the parser `my` and its associated input stream.
+  lexbase.close(my)
+
+proc str*(my: JsonParser): string {.inline.} =
+  ## returns the character data for the events: ``jsonInt``, ``jsonFloat``,
+  ## ``jsonString``
+  assert(my.kind in {jsonInt, jsonFloat, jsonString})
+  return my.a
+
+proc getInt*(my: JsonParser): BiggestInt {.inline.} =
+  ## returns the number for the event: ``jsonInt``
+  assert(my.kind == jsonInt)
+  return parseBiggestInt(my.a)
+
+proc getFloat*(my: JsonParser): float {.inline.} =
+  ## returns the number for the event: ``jsonFloat``
+  assert(my.kind == jsonFloat)
+  return parseFloat(my.a)
+
+proc kind*(my: JsonParser): JsonEventKind {.inline.} =
+  ## returns the current event type for the JSON parser
+  return my.kind
+
+proc getColumn*(my: JsonParser): int {.inline.} =
+  ## get the current column the parser has arrived at.
+  result = getColNumber(my, my.bufpos)
+
+proc getLine*(my: JsonParser): int {.inline.} =
+  ## get the current line the parser has arrived at.
+  result = my.lineNumber
+
+proc getFilename*(my: JsonParser): string {.inline.} =
+  ## get the filename of the file that the parser processes.
+  result = my.filename
+
+proc errorMsg*(my: JsonParser): string =
+  ## returns a helpful error message for the event ``jsonError``
+  assert(my.kind == jsonError)
+  result = "$1($2, $3) Error: $4" % [
+    my.filename, $getLine(my), $getColumn(my), errorMessages[my.err]]
+
+proc errorMsgExpected*(my: JsonParser, e: string): string =
+  ## returns an error message "`e` expected" in the same format as the
+  ## other error messages
+  result = "$1($2, $3) Error: $4" % [
+    my.filename, $getLine(my), $getColumn(my), e & " expected"]
+
+proc handleHexChar(c: char, x: var int): bool =
+  result = true # Success
+  case c
+  of '0'..'9': x = (x shl 4) or (ord(c) - ord('0'))
+  of 'a'..'f': x = (x shl 4) or (ord(c) - ord('a') + 10)
+  of 'A'..'F': x = (x shl 4) or (ord(c) - ord('A') + 10)
+  else: result = false # error
+
+proc parseEscapedUTF16*(buf: cstring, pos: var int): int =
+  result = 0
+  #UTF-16 escape is always 4 bytes.
+  for _ in 0..3:
+    if handleHexChar(buf[pos], result):
+      inc(pos)
+    else:
+      return -1
+
+proc parseString(my: var JsonParser): TokKind =
+  result = tkString
+  var pos = my.bufpos + 1
+  var buf = my.buf
+  if my.rawStringLiterals:
+    add(my.a, '"')
+  while true:
+    case buf[pos]
+    of '\0':
+      my.err = errQuoteExpected
+      result = tkError
+      break
+    of '"':
+      if my.rawStringLiterals:
+        add(my.a, '"')
+      inc(pos)
+      break
+    of '\\':
+      if my.rawStringLiterals:
+        add(my.a, '\\')
+      case buf[pos+1]
+      of '\\', '"', '\'', '/':
+        add(my.a, buf[pos+1])
+        inc(pos, 2)
+      of 'b':
+        add(my.a, '\b')
+        inc(pos, 2)
+      of 'f':
+        add(my.a, '\f')
+        inc(pos, 2)
+      of 'n':
+        add(my.a, '\L')
+        inc(pos, 2)
+      of 'r':
+        add(my.a, '\C')
+        inc(pos, 2)
+      of 't':
+        add(my.a, '\t')
+        inc(pos, 2)
+      of 'u':
+        if my.rawStringLiterals:
+          add(my.a, 'u')
+        inc(pos, 2)
+        var pos2 = pos
+        var r = parseEscapedUTF16(buf, pos)
+        if r < 0:
+          my.err = errInvalidToken
+          break
+        # Deal with surrogates
+        if (r and 0xfc00) == 0xd800:
+          if buf[pos] != '\\' or buf[pos+1] != 'u':
+            my.err = errInvalidToken
+            break
+          inc(pos, 2)
+          var s = parseEscapedUTF16(buf, pos)
+          if (s and 0xfc00) == 0xdc00 and s > 0:
+            r = 0x10000 + (((r - 0xd800) shl 10) or (s - 0xdc00))
+          else:
+            my.err = errInvalidToken
+            break
+        if my.rawStringLiterals:
+          let length = pos - pos2
+          for i in 1 .. length:
+            if buf[pos2] in {'0'..'9', 'A'..'F', 'a'..'f'}:
+              add(my.a, buf[pos2])
+              inc pos2
+            else:
+              break
+        else:
+          add(my.a, toUTF8(Rune(r)))
+      else:
+        # don't bother with the error
+        add(my.a, buf[pos])
+        inc(pos)
+    of '\c':
+      pos = lexbase.handleCR(my, pos)
+      buf = my.buf
+      add(my.a, '\c')
+    of '\L':
+      pos = lexbase.handleLF(my, pos)
+      buf = my.buf
+      add(my.a, '\L')
+    else:
+      add(my.a, buf[pos])
+      inc(pos)
+  my.bufpos = pos # store back
+
+proc skip(my: var JsonParser) =
+  var pos = my.bufpos
+  var buf = my.buf
+  while true:
+    case buf[pos]
+    of '/':
+      if buf[pos+1] == '/':
+        # skip line comment:
+        inc(pos, 2)
+        while true:
+          case buf[pos]
+          of '\0':
+            break
+          of '\c':
+            pos = lexbase.handleCR(my, pos)
+            buf = my.buf
+            break
+          of '\L':
+            pos = lexbase.handleLF(my, pos)
+            buf = my.buf
+            break
+          else:
+            inc(pos)
+      elif buf[pos+1] == '*':
+        # skip long comment:
+        inc(pos, 2)
+        while true:
+          case buf[pos]
+          of '\0':
+            my.err = errEOC_Expected
+            break
+          of '\c':
+            pos = lexbase.handleCR(my, pos)
+            buf = my.buf
+          of '\L':
+            pos = lexbase.handleLF(my, pos)
+            buf = my.buf
+          of '*':
+            inc(pos)
+            if buf[pos] == '/':
+              inc(pos)
+              break
+          else:
+            inc(pos)
+      else:
+        break
+    of ' ', '\t':
+      inc(pos)
+    of '\c':
+      pos = lexbase.handleCR(my, pos)
+      buf = my.buf
+    of '\L':
+      pos = lexbase.handleLF(my, pos)
+      buf = my.buf
+    else:
+      break
+  my.bufpos = pos
+
+proc parseNumber(my: var JsonParser) =
+  var pos = my.bufpos
+  var buf = my.buf
+  if buf[pos] == '-':
+    add(my.a, '-')
+    inc(pos)
+  if buf[pos] == '.':
+    add(my.a, "0.")
+    inc(pos)
+  else:
+    while buf[pos] in Digits:
+      add(my.a, buf[pos])
+      inc(pos)
+    if buf[pos] == '.':
+      add(my.a, '.')
+      inc(pos)
+  # digits after the dot:
+  while buf[pos] in Digits:
+    add(my.a, buf[pos])
+    inc(pos)
+  if buf[pos] in {'E', 'e'}:
+    add(my.a, buf[pos])
+    inc(pos)
+    if buf[pos] in {'+', '-'}:
+      add(my.a, buf[pos])
+      inc(pos)
+    while buf[pos] in Digits:
+      add(my.a, buf[pos])
+      inc(pos)
+  my.bufpos = pos
+
+proc parseName(my: var JsonParser) =
+  var pos = my.bufpos
+  var buf = my.buf
+  if buf[pos] in IdentStartChars:
+    while buf[pos] in IdentChars:
+      add(my.a, buf[pos])
+      inc(pos)
+  my.bufpos = pos
+
+proc getTok*(my: var JsonParser): TokKind =
+  setLen(my.a, 0)
+  skip(my) # skip whitespace, comments
+  case my.buf[my.bufpos]
+  of '-', '.', '0'..'9':
+    parseNumber(my)
+    if {'.', 'e', 'E'} in my.a:
+      result = tkFloat
+    else:
+      result = tkInt
+  of '"':
+    result = parseString(my)
+  of '[':
+    inc(my.bufpos)
+    result = tkBracketLe
+  of '{':
+    inc(my.bufpos)
+    result = tkCurlyLe
+  of ']':
+    inc(my.bufpos)
+    result = tkBracketRi
+  of '}':
+    inc(my.bufpos)
+    result = tkCurlyRi
+  of ',':
+    inc(my.bufpos)
+    result = tkComma
+  of ':':
+    inc(my.bufpos)
+    result = tkColon
+  of '\0':
+    result = tkEof
+  of 'a'..'z', 'A'..'Z', '_':
+    parseName(my)
+    case my.a
+    of "null": result = tkNull
+    of "true": result = tkTrue
+    of "false": result = tkFalse
+    else: result = tkError
+  else:
+    inc(my.bufpos)
+    result = tkError
+  my.tok = result
+
+
+proc next*(my: var JsonParser) =
+  ## retrieves the first/next event. This controls the parser.
+  var tk = getTok(my)
+  var i = my.state.len-1
+  # the following code is a state machine. If we had proper coroutines,
+  # the code could be much simpler.
+  case my.state[i]
+  of stateEof:
+    if tk == tkEof:
+      my.kind = jsonEof
+    else:
+      my.kind = jsonError
+      my.err = errEofExpected
+  of stateStart:
+    # tokens allowed?
+    case tk
+    of tkString, tkInt, tkFloat, tkTrue, tkFalse, tkNull:
+      my.state[i] = stateEof # expect EOF next!
+      my.kind = JsonEventKind(ord(tk))
+    of tkBracketLe:
+      my.state.add(stateArray) # we expect any
+      my.kind = jsonArrayStart
+    of tkCurlyLe:
+      my.state.add(stateObject)
+      my.kind = jsonObjectStart
+    of tkEof:
+      my.kind = jsonEof
+    else:
+      my.kind = jsonError
+      my.err = errEofExpected
+  of stateObject:
+    case tk
+    of tkString, tkInt, tkFloat, tkTrue, tkFalse, tkNull:
+      my.state.add(stateExpectColon)
+      my.kind = JsonEventKind(ord(tk))
+    of tkBracketLe:
+      my.state.add(stateExpectColon)
+      my.state.add(stateArray)
+      my.kind = jsonArrayStart
+    of tkCurlyLe:
+      my.state.add(stateExpectColon)
+      my.state.add(stateObject)
+      my.kind = jsonObjectStart
+    of tkCurlyRi:
+      my.kind = jsonObjectEnd
+      discard my.state.pop()
+    else:
+      my.kind = jsonError
+      my.err = errCurlyRiExpected
+  of stateArray:
+    case tk
+    of tkString, tkInt, tkFloat, tkTrue, tkFalse, tkNull:
+      my.state.add(stateExpectArrayComma) # expect value next!
+      my.kind = JsonEventKind(ord(tk))
+    of tkBracketLe:
+      my.state.add(stateExpectArrayComma)
+      my.state.add(stateArray)
+      my.kind = jsonArrayStart
+    of tkCurlyLe:
+      my.state.add(stateExpectArrayComma)
+      my.state.add(stateObject)
+      my.kind = jsonObjectStart
+    of tkBracketRi:
+      my.kind = jsonArrayEnd
+      discard my.state.pop()
+    else:
+      my.kind = jsonError
+      my.err = errBracketRiExpected
+  of stateExpectArrayComma:
+    case tk
+    of tkComma:
+      discard my.state.pop()
+      next(my)
+    of tkBracketRi:
+      my.kind = jsonArrayEnd
+      discard my.state.pop() # pop stateExpectArrayComma
+      discard my.state.pop() # pop stateArray
+    else:
+      my.kind = jsonError
+      my.err = errBracketRiExpected
+  of stateExpectObjectComma:
+    case tk
+    of tkComma:
+      discard my.state.pop()
+      next(my)
+    of tkCurlyRi:
+      my.kind = jsonObjectEnd
+      discard my.state.pop() # pop stateExpectObjectComma
+      discard my.state.pop() # pop stateObject
+    else:
+      my.kind = jsonError
+      my.err = errCurlyRiExpected
+  of stateExpectColon:
+    case tk
+    of tkColon:
+      my.state[i] = stateExpectValue
+      next(my)
+    else:
+      my.kind = jsonError
+      my.err = errColonExpected
+  of stateExpectValue:
+    case tk
+    of tkString, tkInt, tkFloat, tkTrue, tkFalse, tkNull:
+      my.state[i] = stateExpectObjectComma
+      my.kind = JsonEventKind(ord(tk))
+    of tkBracketLe:
+      my.state[i] = stateExpectObjectComma
+      my.state.add(stateArray)
+      my.kind = jsonArrayStart
+    of tkCurlyLe:
+      my.state[i] = stateExpectObjectComma
+      my.state.add(stateObject)
+      my.kind = jsonObjectStart
+    else:
+      my.kind = jsonError
+      my.err = errExprExpected
+
+proc raiseParseErr*(p: JsonParser, msg: string) {.noinline, noreturn.} =
+  ## raises an `EJsonParsingError` exception.
+  raise newException(JsonParsingError, errorMsgExpected(p, msg))
+
+proc eat*(p: var JsonParser, tok: TokKind) =
+  if p.tok == tok: discard getTok(p)
+  else: raiseParseErr(p, tokToStr[tok])
diff --git a/lib/pure/parseutils.nim b/lib/pure/parseutils.nim
index d77790fe0..d54f1454b 100644
--- a/lib/pure/parseutils.nim
+++ b/lib/pure/parseutils.nim
@@ -197,6 +197,9 @@ proc parseUntil*(s: string, token: var string, until: string,
   ## parses a token and stores it in ``token``. Returns
   ## the number of the parsed characters or 0 in case of an error. A token
   ## consists of any character that comes before the `until`  token.
+  if until.len == 0:
+    token.setLen(0)
+    return 0
   var i = start
   while i < s.len:
     if s[i] == until[0]:
diff --git a/lib/pure/pegs.nim b/lib/pure/pegs.nim
index 830429842..39c5790ed 100644
--- a/lib/pure/pegs.nim
+++ b/lib/pure/pegs.nim
@@ -1010,14 +1010,18 @@ proc replace*(s: string, sub: Peg, cb: proc(
       inc(m)
   add(result, substr(s, i))
 
-proc transformFile*(infile, outfile: string,
-                    subs: varargs[tuple[pattern: Peg, repl: string]]) {.
-                    rtl, extern: "npegs$1".} =
-  ## reads in the file `infile`, performs a parallel replacement (calls
-  ## `parallelReplace`) and writes back to `outfile`. Raises ``EIO`` if an
-  ## error occurs. This is supposed to be used for quick scripting.
-  var x = readFile(infile).string
-  writeFile(outfile, x.parallelReplace(subs))
+when not defined(js):
+  proc transformFile*(infile, outfile: string,
+                      subs: varargs[tuple[pattern: Peg, repl: string]]) {.
+                      rtl, extern: "npegs$1".} =
+    ## reads in the file `infile`, performs a parallel replacement (calls
+    ## `parallelReplace`) and writes back to `outfile`. Raises ``EIO`` if an
+    ## error occurs. This is supposed to be used for quick scripting.
+    ##
+    ## **Note**: this proc does not exist while using the JS backend.
+    var x = readFile(infile).string
+    writeFile(outfile, x.parallelReplace(subs))
+
 
 iterator split*(s: string, sep: Peg): string =
   ## Splits the string `s` into substrings.
@@ -1121,7 +1125,7 @@ proc handleCR(L: var PegLexer, pos: int): int =
   assert(L.buf[pos] == '\c')
   inc(L.lineNumber)
   result = pos+1
-  if L.buf[result] == '\L': inc(result)
+  if result < L.buf.len and L.buf[result] == '\L': inc(result)
   L.lineStart = result
 
 proc handleLF(L: var PegLexer, pos: int): int =
@@ -1217,12 +1221,13 @@ proc getEscapedChar(c: var PegLexer, tok: var Token) =
 proc skip(c: var PegLexer) =
   var pos = c.bufpos
   var buf = c.buf
-  while true:
+  while pos < c.buf.len:
     case buf[pos]
     of ' ', '\t':
       inc(pos)
     of '#':
-      while not (buf[pos] in {'\c', '\L', '\0'}): inc(pos)
+      while (pos < c.buf.len) and
+             not (buf[pos] in {'\c', '\L', '\0'}): inc(pos)
     of '\c':
       pos = handleCR(c, pos)
       buf = c.buf
@@ -1238,7 +1243,7 @@ proc getString(c: var PegLexer, tok: var Token) =
   var pos = c.bufpos + 1
   var buf = c.buf
   var quote = buf[pos-1]
-  while true:
+  while pos < c.buf.len:
     case buf[pos]
     of '\\':
       c.bufpos = pos
@@ -1261,7 +1266,7 @@ proc getDollar(c: var PegLexer, tok: var Token) =
   if buf[pos] in {'0'..'9'}:
     tok.kind = tkBackref
     tok.index = 0
-    while buf[pos] in {'0'..'9'}:
+    while pos < c.buf.len and buf[pos] in {'0'..'9'}:
       tok.index = tok.index * 10 + ord(buf[pos]) - ord('0')
       inc(pos)
   else:
@@ -1277,11 +1282,11 @@ proc getCharSet(c: var PegLexer, tok: var Token) =
   if buf[pos] == '^':
     inc(pos)
     caret = true
-  while true:
+  while pos < c.buf.len:
     var ch: char
     case buf[pos]
     of ']':
-      inc(pos)
+      if pos < c.buf.len: inc(pos)
       break
     of '\\':
       c.bufpos = pos
@@ -1296,11 +1301,14 @@ proc getCharSet(c: var PegLexer, tok: var Token) =
       inc(pos)
     incl(tok.charset, ch)
     if buf[pos] == '-':
-      if buf[pos+1] == ']':
+      if pos+1 < c.buf.len and buf[pos+1] == ']':
         incl(tok.charset, '-')
         inc(pos)
       else:
-        inc(pos)
+        if pos+1 < c.buf.len:
+          inc(pos)
+        else:
+          break
         var ch2: char
         case buf[pos]
         of '\\':
@@ -1312,8 +1320,11 @@ proc getCharSet(c: var PegLexer, tok: var Token) =
           tok.kind = tkInvalid
           break
         else:
-          ch2 = buf[pos]
-          inc(pos)
+          if pos+1 < c.buf.len:
+            ch2 = buf[pos]
+            inc(pos)
+          else:
+            break
         for i in ord(ch)+1 .. ord(ch2):
           incl(tok.charset, chr(i))
   c.bufpos = pos
@@ -1322,15 +1333,15 @@ proc getCharSet(c: var PegLexer, tok: var Token) =
 proc getSymbol(c: var PegLexer, tok: var Token) =
   var pos = c.bufpos
   var buf = c.buf
-  while true:
+  while pos < c.buf.len:
     add(tok.literal, buf[pos])
     inc(pos)
-    if buf[pos] notin strutils.IdentChars: break
+    if pos < buf.len and buf[pos] notin strutils.IdentChars: break
   c.bufpos = pos
   tok.kind = tkIdentifier
 
 proc getBuiltin(c: var PegLexer, tok: var Token) =
-  if c.buf[c.bufpos+1] in strutils.Letters:
+  if c.bufpos+1 < c.buf.len and c.buf[c.bufpos+1] in strutils.Letters:
     inc(c.bufpos)
     getSymbol(c, tok)
     tok.kind = tkBuiltin
@@ -1343,10 +1354,12 @@ proc getTok(c: var PegLexer, tok: var Token) =
   tok.modifier = modNone
   setLen(tok.literal, 0)
   skip(c)
+
   case c.buf[c.bufpos]
   of '{':
     inc(c.bufpos)
-    if c.buf[c.bufpos] == '@' and c.buf[c.bufpos+1] == '}':
+    if c.buf[c.bufpos] == '@' and c.bufpos+2 < c.buf.len and
+      c.buf[c.bufpos+1] == '}':
       tok.kind = tkCurlyAt
       inc(c.bufpos, 2)
       add(tok.literal, "{@}")
@@ -1379,13 +1392,11 @@ proc getTok(c: var PegLexer, tok: var Token) =
     getBuiltin(c, tok)
   of '\'', '"': getString(c, tok)
   of '$': getDollar(c, tok)
-  of '\0':
-    tok.kind = tkEof
-    tok.literal = "[EOF]"
   of 'a'..'z', 'A'..'Z', '\128'..'\255':
     getSymbol(c, tok)
     if c.buf[c.bufpos] in {'\'', '"'} or
-        c.buf[c.bufpos] == '$' and c.buf[c.bufpos+1] in {'0'..'9'}:
+        c.buf[c.bufpos] == '$' and c.bufpos+1 < c.buf.len and
+        c.buf[c.bufpos+1] in {'0'..'9'}:
       case tok.literal
       of "i": tok.modifier = modIgnoreCase
       of "y": tok.modifier = modIgnoreStyle
@@ -1406,7 +1417,7 @@ proc getTok(c: var PegLexer, tok: var Token) =
     inc(c.bufpos)
     add(tok.literal, '+')
   of '<':
-    if c.buf[c.bufpos+1] == '-':
+    if c.bufpos+2 < c.buf.len and c.buf[c.bufpos+1] == '-':
       inc(c.bufpos, 2)
       tok.kind = tkArrow
       add(tok.literal, "<-")
@@ -1441,14 +1452,17 @@ proc getTok(c: var PegLexer, tok: var Token) =
     inc(c.bufpos)
     add(tok.literal, '^')
   else:
+    if c.bufpos >= c.buf.len:
+      tok.kind = tkEof
+      tok.literal = "[EOF]"
     add(tok.literal, c.buf[c.bufpos])
     inc(c.bufpos)
 
 proc arrowIsNextTok(c: PegLexer): bool =
   # the only look ahead we need
   var pos = c.bufpos
-  while c.buf[pos] in {'\t', ' '}: inc(pos)
-  result = c.buf[pos] == '<' and c.buf[pos+1] == '-'
+  while pos < c.buf.len and c.buf[pos] in {'\t', ' '}: inc(pos)
+  result = c.buf[pos] == '<' and (pos+1 < c.buf.len) and c.buf[pos+1] == '-'
 
 # ----------------------------- parser ----------------------------------------
 
@@ -1471,7 +1485,7 @@ proc pegError(p: PegParser, msg: string, line = -1, col = -1) =
 
 proc getTok(p: var PegParser) =
   getTok(p, p.tok)
-  if p.tok.kind == tkInvalid: pegError(p, "invalid token")
+  if p.tok.kind == tkInvalid: pegError(p, "'" & p.tok.literal & "' is invalid token")
 
 proc eat(p: var PegParser, kind: TokKind) =
   if p.tok.kind == kind: getTok(p)
diff --git a/lib/pure/rationals.nim b/lib/pure/rationals.nim
index 7907b4e6c..3946cf85b 100644
--- a/lib/pure/rationals.nim
+++ b/lib/pure/rationals.nim
@@ -241,6 +241,33 @@ proc abs*[T](x: Rational[T]): Rational[T] =
   result.num = abs x.num
   result.den = abs x.den
 
+proc `div`*[T: SomeInteger](x, y: Rational[T]): T =
+  ## Computes the rational truncated division.
+  (x.num * y.den) div (y.num * x.den)
+
+proc `mod`*[T: SomeInteger](x, y: Rational[T]): Rational[T] =
+  ## Computes the rational modulo by truncated division (remainder).
+  ## This is same as ``x - (x div y) * y``.
+  result = ((x.num * y.den) mod (y.num * x.den)) // (x.den * y.den)
+  reduce(result)
+
+proc floorDiv*[T: SomeInteger](x, y: Rational[T]): T =
+  ## Computes the rational floor division.
+  ##
+  ## Floor division is conceptually defined as ``floor(x / y)``.
+  ## This is different from the ``div`` operator, which is defined
+  ## as ``trunc(x / y)``. That is, ``div`` rounds towards ``0`` and ``floorDiv``
+  ## rounds down.
+  floorDiv(x.num * y.den, y.num * x.den)
+
+proc floorMod*[T: SomeInteger](x, y: Rational[T]): Rational[T] =
+  ## Computes the rational modulo by floor division (modulo).
+  ##
+  ## This is same as ``x - floorDiv(x, y) * y``.
+  ## This proc behaves the same as the ``%`` operator in python.
+  result = floorMod(x.num * y.den, y.num * x.den) // (x.den * y.den)
+  reduce(result)
+
 proc hash*[T](x: Rational[T]): Hash =
   ## Computes hash for rational `x`
   # reduce first so that hash(x) == hash(y) for x == y
@@ -339,3 +366,12 @@ when isMainModule:
   assert toRational(0.33) == 33 // 100
   assert toRational(0.22) == 11 // 50
   assert toRational(10.0) == 10 // 1
+
+  assert (1//1) div (3//10) == 3
+  assert (-1//1) div (3//10) == -3
+  assert (3//10) mod (1//1) == 3//10
+  assert (-3//10) mod (1//1) == -3//10
+  assert floorDiv(1//1, 3//10) == 3
+  assert floorDiv(-1//1, 3//10) == -4
+  assert floorMod(3//10, 1//1) == 3//10
+  assert floorMod(-3//10, 1//1) == 7//10
diff --git a/lib/pure/streams.nim b/lib/pure/streams.nim
index 68922f730..a0bba05a4 100644
--- a/lib/pure/streams.nim
+++ b/lib/pure/streams.nim
@@ -86,18 +86,20 @@ proc readData*(s: Stream, buffer: pointer, bufLen: int): int =
   ## low level proc that reads data into an untyped `buffer` of `bufLen` size.
   result = s.readDataImpl(s, buffer, bufLen)
 
-proc readAll*(s: Stream): string =
-  ## Reads all available data.
-  const bufferSize = 1000
-  result = newString(bufferSize)
-  var r = 0
-  while true:
-    let readBytes = readData(s, addr(result[r]), bufferSize)
-    if readBytes < bufferSize:
-      setLen(result, r+readBytes)
-      break
-    inc r, bufferSize
-    setLen(result, r+bufferSize)
+when not defined(js):
+  proc readAll*(s: Stream): string =
+    ## Reads all available data.
+    const bufferSize = 1024
+    var buffer {.noinit.}: array[bufferSize, char]
+    while true:
+      let readBytes = readData(s, addr(buffer[0]), bufferSize)
+      if readBytes == 0:
+        break
+      let prevLen = result.len
+      result.setLen(prevLen + readBytes)
+      copyMem(addr(result[prevLen]), addr(buffer[0]), readBytes)
+      if readBytes < bufferSize:
+        break
 
 proc peekData*(s: Stream, buffer: pointer, bufLen: int): int =
   ## low level proc that reads data into an untyped `buffer` of `bufLen` size
@@ -131,7 +133,7 @@ proc write*(s: Stream, x: string) =
   when nimvm:
     writeData(s, cstring(x), x.len)
   else:
-    if x.len > 0: writeData(s, unsafeAddr x[0], x.len)
+    if x.len > 0: writeData(s, cstring(x), x.len)
 
 proc writeLine*(s: Stream, args: varargs[string, `$`]) =
   ## writes one or more strings to the the stream `s` followed
@@ -251,14 +253,14 @@ proc readStr*(s: Stream, length: int): TaintedString =
   ## reads a string of length `length` from the stream `s`. Raises `EIO` if
   ## an error occurred.
   result = newString(length).TaintedString
-  var L = readData(s, addr(string(result)[0]), length)
+  var L = readData(s, cstring(result), length)
   if L != length: setLen(result.string, L)
 
 proc peekStr*(s: Stream, length: int): TaintedString =
   ## peeks a string of length `length` from the stream `s`. Raises `EIO` if
   ## an error occurred.
   result = newString(length).TaintedString
-  var L = peekData(s, addr(string(result)[0]), length)
+  var L = peekData(s, cstring(result), length)
   if L != length: setLen(result.string, L)
 
 proc readLine*(s: Stream, line: var TaintedString): bool =
diff --git a/lib/pure/strformat.nim b/lib/pure/strformat.nim
index a8b128460..36404cdf7 100644
--- a/lib/pure/strformat.nim
+++ b/lib/pure/strformat.nim
@@ -524,8 +524,31 @@ proc format*(value: SomeFloat; specifier: string; res: var string) =
       " of 'e', 'E', 'f', 'F', 'g', 'G' but got: " & spec.typ)
 
   var f = formatBiggestFloat(value, fmode, spec.precision)
-  if value >= 0.0 and spec.sign != '-':
-    f = spec.sign & f
+  var sign = false
+  if value >= 0.0:
+    if spec.sign != '-':
+      sign = true
+      if  value == 0.0:
+        if 1.0 / value == Inf:
+          # only insert the sign if value != negZero
+          f.insert($spec.sign, 0)
+      else:
+        f.insert($spec.sign, 0)
+  else:
+    sign = true
+
+  if spec.padWithZero:
+    var sign_str = ""
+    if sign:
+      sign_str = $f[0]
+      f = f[1..^1]
+
+    let toFill = spec.minimumWidth - f.len - ord(sign)
+    if toFill > 0:
+      f = repeat('0', toFill) & f
+    if sign:
+      f = sign_str & f
+
   # the default for numbers is right-alignment:
   let align = if spec.align == '\0': '>' else: spec.align
   let result = alignString(f, spec.minimumWidth,
@@ -540,12 +563,16 @@ proc format*(value: string; specifier: string; res: var string) =
   ## sense to call this directly, but it is required to exist
   ## by the ``&`` macro.
   let spec = parseStandardFormatSpecifier(specifier)
+  var value = value
   case spec.typ
   of 's', '\0': discard
   else:
     raise newException(ValueError,
       "invalid type in format string for string, expected 's', but got " &
       spec.typ)
+  if spec.precision != -1:
+    if spec.precision < runelen(value):
+      setLen(value, runeOffset(value, spec.precision))
   res.add alignString(value, spec.minimumWidth, spec.align, spec.fill)
 
 when isMainModule:
diff --git a/lib/pure/strscans.nim b/lib/pure/strscans.nim
index b0af149b5..11f182495 100644
--- a/lib/pure/strscans.nim
+++ b/lib/pure/strscans.nim
@@ -316,6 +316,9 @@ macro scanf*(input: string; pattern: static[string]; results: varargs[typed]): b
     conds.add resLen
 
   template at(s: string; i: int): char = (if i < s.len: s[i] else: '\0')
+  template matchError() =
+    error("type mismatch between pattern '$" & pattern[p] & "' (position: " & $p & ") and " & $getType(results[i]) &
+          " var '" & repr(results[i]) & "'")
 
   var i = 0
   var p = 0
@@ -338,37 +341,37 @@ macro scanf*(input: string; pattern: static[string]; results: varargs[typed]): b
         if i < results.len and getType(results[i]).typeKind == ntyString:
           matchBind "parseIdent"
         else:
-          error("no string var given for $w")
+          matchError
         inc i
       of 'b':
         if i < results.len and getType(results[i]).typeKind == ntyInt:
           matchBind "parseBin"
         else:
-          error("no int var given for $b")
+          matchError
         inc i
       of 'o':
         if i < results.len and getType(results[i]).typeKind == ntyInt:
           matchBind "parseOct"
         else:
-          error("no int var given for $o")
+          matchError
         inc i
       of 'i':
         if i < results.len and getType(results[i]).typeKind == ntyInt:
           matchBind "parseInt"
         else:
-          error("no int var given for $i")
+          matchError
         inc i
       of 'h':
         if i < results.len and getType(results[i]).typeKind == ntyInt:
           matchBind "parseHex"
         else:
-          error("no int var given for $h")
+          matchError
         inc i
       of 'f':
         if i < results.len and getType(results[i]).typeKind == ntyFloat:
           matchBind "parseFloat"
         else:
-          error("no float var given for $f")
+          matchError
         inc i
       of 's':
         conds.add newCall(bindSym"inc", idx, newCall(bindSym"skipWhitespace", inp, idx))
@@ -392,7 +395,7 @@ macro scanf*(input: string; pattern: static[string]; results: varargs[typed]): b
           conds.add newCall(bindSym"!=", resLen, newLit min)
           conds.add resLen
         else:
-          error("no string var given for $" & pattern[p])
+          matchError
         inc i
       of '{':
         inc p
@@ -414,7 +417,7 @@ macro scanf*(input: string; pattern: static[string]; results: varargs[typed]): b
           conds.add newCall(bindSym"!=", resLen, newLit 0)
           conds.add resLen
         else:
-          error("no var given for $" & expr)
+          error("no var given for $" & expr & " (position: " & $p & ")")
         inc i
       of '[':
         inc p
diff --git a/lib/pure/strutils.nim b/lib/pure/strutils.nim
index ee3072c85..a4fd20fdb 100644
--- a/lib/pure/strutils.nim
+++ b/lib/pure/strutils.nim
@@ -1854,6 +1854,10 @@ proc formatBiggestFloat*(f: BiggestFloat, format: FloatFormatMode = ffDefault,
   ##
   ## If ``precision == -1``, it tries to format it nicely.
   when defined(js):
+    var precision = precision
+    if precision == -1:
+      # use the same default precision as c_sprintf
+      precision = 6
     var res: cstring
     case format
     of ffDefault:
@@ -1863,6 +1867,9 @@ proc formatBiggestFloat*(f: BiggestFloat, format: FloatFormatMode = ffDefault,
     of ffScientific:
       {.emit: "`res` = `f`.toExponential(`precision`);".}
     result = $res
+    if 1.0 / f == -Inf:
+      # JavaScript removes the "-" from negative Zero, add it back here
+      result = "-" & $res
     for i in 0 ..< result.len:
       # Depending on the locale either dot or comma is produced,
       # but nothing else is possible:
diff --git a/lib/pure/times.nim b/lib/pure/times.nim
index f6567cf58..60b362665 100644
--- a/lib/pure/times.nim
+++ b/lib/pure/times.nim
@@ -35,7 +35,7 @@
                       # of the standard library!
 
 import
-  strutils, parseutils
+  strutils, parseutils, algorithm, math
 
 include "system/inclrtl"
 
@@ -183,6 +183,11 @@ type
                     ## The point in time represented by ``ZonedTime`` is ``adjTime + utcOffset.seconds``.
     isDst*: bool    ## Determines whether DST is in effect.
 
+  DurationParts* = array[FixedTimeUnit, int64] # Array of Duration parts starts
+  TimeIntervalParts* = array[TimeUnit, int] # Array of Duration parts starts
+
+
+
 {.deprecated: [TMonth: Month, TWeekDay: WeekDay, TTime: Time,
     TTimeInterval: TimeInterval, TTimeInfo: DateTime, TimeInfo: DateTime].}
 
@@ -229,31 +234,23 @@ proc normalize[T: Duration|Time](seconds, nanoseconds: int64): T =
     result.seconds -= 1
   result.nanosecond = nanosecond.int
 
-proc initTime*(unix: int64, nanosecond: NanosecondRange): Time =
-  ## Create a ``Time`` from a unix timestamp and a nanosecond part.
-  result.seconds = unix
-  result.nanosecond = nanosecond
+# Forward declarations
+proc utcZoneInfoFromUtc(time: Time): ZonedTime {.tags: [], raises: [], benign .}
+proc utcZoneInfoFromTz(adjTime: Time): ZonedTime {.tags: [], raises: [], benign .}
+proc localZoneInfoFromUtc(time: Time): ZonedTime {.tags: [], raises: [], benign .}
+proc localZoneInfoFromTz(adjTime: Time): ZonedTime {.tags: [], raises: [], benign .}
+proc initTime*(unix: int64, nanosecond: NanosecondRange): Time 
+  {.tags: [], raises: [], benign noSideEffect.}
+
+proc initDuration*(nanoseconds, microseconds, milliseconds,
+                   seconds, minutes, hours, days, weeks: int64 = 0): Duration 
+  {.tags: [], raises: [], benign noSideEffect.}
 
 proc nanosecond*(time: Time): NanosecondRange =
   ## Get the fractional part of a ``Time`` as the number
   ## of nanoseconds of the second.
   time.nanosecond
 
-proc initDuration*(nanoseconds, microseconds, milliseconds,
-                   seconds, minutes, hours, days, weeks: int64 = 0): Duration =
-  let seconds = convert(Weeks, Seconds, weeks) +
-    convert(Days, Seconds, days) +
-    convert(Minutes, Seconds, minutes) +
-    convert(Hours, Seconds, hours) +
-    convert(Seconds, Seconds, seconds) +
-    convert(Milliseconds, Seconds, milliseconds) +
-    convert(Microseconds, Seconds, microseconds) +
-    convert(Nanoseconds, Seconds, nanoseconds)
-  let nanoseconds = (convert(Milliseconds, Nanoseconds, milliseconds mod 1000) +
-    convert(Microseconds, Nanoseconds, microseconds mod 1_000_000) +
-    nanoseconds mod 1_000_000_000).int
-  # Nanoseconds might be negative so we must normalize.
-  result = normalize[Duration](seconds, nanoseconds)
 
 proc weeks*(dur: Duration): int64 {.inline.} =
   ## Number of whole weeks represented by the duration.
@@ -306,63 +303,6 @@ proc fractional*(dur: Duration): Duration {.inline.} =
     doAssert dur.fractional == initDuration(nanoseconds = 5)
   initDuration(nanoseconds = dur.nanosecond)
 
-const DurationZero* = initDuration() ## Zero value for durations. Useful for comparisons.
-                                     ##
-                                     ## .. code-block:: nim
-                                     ##
-                                     ##   doAssert initDuration(seconds = 1) > DurationZero
-                                     ##   doAssert initDuration(seconds = 0) == DurationZero
-
-proc `$`*(dur: Duration): string =
-  ## Human friendly string representation of ``dur``.
-  runnableExamples:
-    doAssert $initDuration(seconds = 2) == "2 seconds"
-    doAssert $initDuration(weeks = 1, days = 2) == "1 week and 2 days"
-    doAssert $initDuration(hours = 1, minutes = 2, seconds = 3) == "1 hour, 2 minutes, and 3 seconds"
-    doAssert $initDuration(milliseconds = -1500) == "-1 second and -500 milliseconds"
-  var parts = newSeq[string]()
-  var remS = dur.seconds
-  var remNs = dur.nanosecond.int
-
-  # Normally ``nanoseconds`` should always be positive, but
-  # that makes no sense when printing.
-  if remS < 0:
-    remNs -= convert(Seconds, Nanoseconds, 1)
-    remS.inc 1
-
-  const unitStrings: array[FixedTimeUnit, string] = [
-    "nanosecond", "microsecond", "millisecond", "second", "minute", "hour", "day", "week"
-  ]
-
-  for unit in countdown(Weeks, Seconds):
-    let quantity = convert(Seconds, unit, remS)
-    remS = remS mod convert(unit, Seconds, 1)
-
-    if quantity.abs == 1:
-      parts.add $quantity & " " & unitStrings[unit]
-    elif quantity != 0:
-      parts.add $quantity & " " & unitStrings[unit] & "s"
-
-  for unit in countdown(Milliseconds, Nanoseconds):
-    let quantity = convert(Nanoseconds, unit, remNs)
-    remNs = remNs mod convert(unit, Nanoseconds, 1)
-
-    if quantity.abs == 1:
-      parts.add $quantity & " " & unitStrings[unit]
-    elif quantity != 0:
-      parts.add $quantity & " " & unitStrings[unit] & "s"
-
-  result = ""
-  if parts.len == 0:
-    result.add "0 nanoseconds"
-  elif parts.len == 1:
-    result = parts[0]
-  elif parts.len == 2:
-    result = parts[0] & " and " & parts[1]
-  else:
-    for part in parts[0..high(parts)-1]:
-      result.add part & ", "
-    result.add "and " & parts[high(parts)]
 
 proc fromUnix*(unix: int64): Time {.benign, tags: [], raises: [], noSideEffect.} =
   ## Convert a unix timestamp (seconds since ``1970-01-01T00:00:00Z``) to a ``Time``.
@@ -372,6 +312,9 @@ proc fromUnix*(unix: int64): Time {.benign, tags: [], raises: [], noSideEffect.}
 
 proc toUnix*(t: Time): int64 {.benign, tags: [], raises: [], noSideEffect.} =
   ## Convert ``t`` to a unix timestamp (seconds since ``1970-01-01T00:00:00Z``).
+  runnableExamples:
+    doAssert fromUnix(0).toUnix() == 0
+
   t.seconds
 
 proc fromWinTime*(win: int64): Time =
@@ -464,11 +407,6 @@ proc getDayOfWeek*(monthday: MonthdayRange, month: Month, year: int): WeekDay {.
   # so we must correct for the WeekDay type.
   result = if wd == 0: dSun else: WeekDay(wd - 1)
 
-# Forward declarations
-proc utcZoneInfoFromUtc(time: Time): ZonedTime {.tags: [], raises: [], benign .}
-proc utcZoneInfoFromTz(adjTime: Time): ZonedTime {.tags: [], raises: [], benign .}
-proc localZoneInfoFromUtc(time: Time): ZonedTime {.tags: [], raises: [], benign .}
-proc localZoneInfoFromTz(adjTime: Time): ZonedTime {.tags: [], raises: [], benign .}
 
 {. pragma: operator, rtl, noSideEffect, benign .}
 
@@ -489,6 +427,114 @@ template lqImpl(a: Duration|Time, b: Duration|Time): bool =
 template eqImpl(a: Duration|Time, b: Duration|Time): bool =
   a.seconds == b.seconds and a.nanosecond == b.nanosecond
 
+proc initDuration*(nanoseconds, microseconds, milliseconds,
+                   seconds, minutes, hours, days, weeks: int64 = 0): Duration =
+  runnableExamples:
+    let dur = initDuration(seconds = 1, milliseconds = 1)
+    doAssert dur.milliseconds == 1
+    doAssert dur.seconds == 1
+
+  let seconds = convert(Weeks, Seconds, weeks) +
+    convert(Days, Seconds, days) +
+    convert(Minutes, Seconds, minutes) +
+    convert(Hours, Seconds, hours) +
+    convert(Seconds, Seconds, seconds) +
+    convert(Milliseconds, Seconds, milliseconds) +
+    convert(Microseconds, Seconds, microseconds) +
+    convert(Nanoseconds, Seconds, nanoseconds)
+  let nanoseconds = (convert(Milliseconds, Nanoseconds, milliseconds mod 1000) +
+    convert(Microseconds, Nanoseconds, microseconds mod 1_000_000) +
+    nanoseconds mod 1_000_000_000).int
+  # Nanoseconds might be negative so we must normalize.
+  result = normalize[Duration](seconds, nanoseconds)
+
+const DurationZero* = initDuration() ## \
+  ## Zero value for durations. Useful for comparisons.
+  ##
+  ## .. code-block:: nim
+  ##
+  ##   doAssert initDuration(seconds = 1) > DurationZero
+  ##   doAssert initDuration(seconds = 0) == DurationZero
+
+proc toParts*(dur: Duration): DurationParts =
+  ## Converts a duration into an array consisting of fixed time units.
+  ##
+  ## Each value in the array gives information about a specific unit of
+  ## time, for example ``result[Days]`` gives a count of days.
+  ##
+  ## This procedure is useful for converting ``Duration`` values to strings.
+  runnableExamples:
+    var dp = toParts(initDuration(weeks=2, days=1))
+    doAssert dp[Days] == 1
+    doAssert dp[Weeks] == 2
+    dp = toParts(initDuration(days = -1))
+    doAssert dp[Days] == -1
+
+  var remS = dur.seconds
+  var remNs = dur.nanosecond.int
+
+  # Ensure the same sign for seconds and nanoseconds
+  if remS < 0 and remNs != 0:
+    remNs -= convert(Seconds, Nanoseconds, 1)
+    remS.inc 1
+
+  for unit in countdown(Weeks, Seconds):
+    let quantity = convert(Seconds, unit, remS)
+    remS = remS mod convert(unit, Seconds, 1)
+
+    result[unit] = quantity
+
+  for unit in countdown(Milliseconds, Nanoseconds):
+    let quantity = convert(Nanoseconds, unit, remNs)
+    remNs = remNs mod convert(unit, Nanoseconds, 1)
+
+    result[unit] = quantity
+
+proc stringifyUnit*(value: int | int64, unit: string): string =
+  ## Stringify time unit with it's name, lowercased
+  runnableExamples:
+    doAssert stringifyUnit(2, "Seconds") == "2 seconds"
+    doAssert stringifyUnit(1, "Years") == "1 year"
+  result = ""
+  result.add($value)
+  result.add(" ")
+  if abs(value) != 1:
+    result.add(unit.toLowerAscii())
+  else:
+    result.add(unit[0..^2].toLowerAscii())
+
+proc humanizeParts(parts: seq[string]): string =
+  ## Make date string parts human-readable
+
+  result = ""
+  if parts.len == 0:
+    result.add "0 nanoseconds"
+  elif parts.len == 1:
+    result = parts[0]
+  elif parts.len == 2:
+    result = parts[0] & " and " & parts[1]
+  else:
+    for part in parts[0..high(parts)-1]:
+      result.add part & ", "
+    result.add "and " & parts[high(parts)]
+
+proc `$`*(dur: Duration): string =
+  ## Human friendly string representation of ``Duration``.
+  runnableExamples:
+    doAssert $initDuration(seconds = 2) == "2 seconds"
+    doAssert $initDuration(weeks = 1, days = 2) == "1 week and 2 days"
+    doAssert $initDuration(hours = 1, minutes = 2, seconds = 3) == "1 hour, 2 minutes, and 3 seconds"
+    doAssert $initDuration(milliseconds = -1500) == "-1 second and -500 milliseconds"
+  var parts = newSeq[string]()
+  var numParts = toParts(dur)
+
+  for unit in countdown(Weeks, Nanoseconds):
+    let quantity = numParts[unit]
+    if quantity != 0.int64:
+      parts.add(stringifyUnit(quantity, $unit))
+  
+  result = humanizeParts(parts)
+
 proc `+`*(a, b: Duration): Duration {.operator.} =
   ## Add two durations together.
   runnableExamples:
@@ -535,7 +581,7 @@ proc `*`*(a: int64, b: Duration): Duration {.operator} =
 proc `*`*(a: Duration, b: int64): Duration {.operator} =
   ## Multiply a duration by some scalar.
   runnableExamples:
-    doAssert 5 * initDuration(seconds = 1) == initDuration(seconds = 5)
+    doAssert initDuration(seconds = 1) * 5 == initDuration(seconds = 5)
   b * a
 
 proc `div`*(a: Duration, b: int64): Duration {.operator} =
@@ -546,6 +592,11 @@ proc `div`*(a: Duration, b: int64): Duration {.operator} =
   let carryOver = convert(Seconds, Nanoseconds, a.seconds mod b)
   normalize[Duration](a.seconds div b, (a.nanosecond + carryOver) div b)
 
+proc initTime*(unix: int64, nanosecond: NanosecondRange): Time =
+  ## Create a ``Time`` from a unix timestamp and a nanosecond part.
+  result.seconds = unix
+  result.nanosecond = nanosecond
+
 proc `-`*(a, b: Time): Duration {.operator, extern: "ntDiffTime".} =
   ## Computes the duration between two points in time.
   subImpl[Duration](a, b)
@@ -556,18 +607,28 @@ proc `+`*(a: Time, b: Duration): Time {.operator, extern: "ntAddTime".} =
     doAssert (fromUnix(0) + initDuration(seconds = 1)) == fromUnix(1)
   addImpl[Time](a, b)
 
+proc `+=`*(a: var Time, b: Duration) {.operator.} =
+  ## Modify ``a`` in place by subtracting ``b``.
+  runnableExamples:
+    var tm = fromUnix(0)
+    tm += initDuration(seconds = 1)
+    doAssert tm == fromUnix(1)
+
+  a = addImpl[Time](a, b)
+
 proc `-`*(a: Time, b: Duration): Time {.operator, extern: "ntSubTime".} =
   ## Subtracts a duration of time from a ``Time``.
   runnableExamples:
     doAssert (fromUnix(0) - initDuration(seconds = 1)) == fromUnix(-1)
   subImpl[Time](a, b)
 
-proc `+=`*(a: var Time, b: Duration) {.operator.} =
-  ## Modify ``a`` in place by subtracting ``b``.
-  a = addImpl[Time](a, b)
-
 proc `-=`*(a: var Time, b: Duration) {.operator.} =
   ## Modify ``a`` in place by adding ``b``.
+  runnableExamples:
+    var tm = fromUnix(0)
+    tm -= initDuration(seconds = 1)
+    doAssert tm == fromUnix(-1)
+
   a = subImpl[Time](a, b)
 
 proc `<`*(a, b: Time): bool {.operator, extern: "ntLtTime".} =
@@ -615,23 +676,8 @@ proc toTime*(dt: DateTime): Time {.tags: [], raises: [], benign.} =
   seconds.inc dt.utcOffset
   result = initTime(seconds, dt.nanosecond)
 
-proc `-`*(dt1, dt2: DateTime): Duration =
-  ## Compute the duration between ``dt1`` and ``dt2``.
-  dt1.toTime - dt2.toTime
-
-proc `<`*(a, b: DateTime): bool =
-  ## Returns true iff ``a < b``, that is iff a happened before b.
-  return a.toTime < b.toTime
-
-proc `<=` * (a, b: DateTime): bool =
-  ## Returns true iff ``a <= b``.
-  return a.toTime <= b.toTime
-
-proc `==`*(a, b: DateTime): bool =
-  ## Returns true if ``a == b``, that is if both dates represent the same point in datetime.
-  return a.toTime == b.toTime
-
 proc initDateTime(zt: ZonedTime, zone: Timezone): DateTime =
+  ## Create a new ``DateTime`` using ``ZonedTime`` in the specified timezone.
   let s = zt.adjTime.seconds
   let epochday = (if s >= 0: s else: s - (secondsInDay - 1)) div secondsInDay
   var rem = s - epochday * secondsInDay
@@ -917,11 +963,10 @@ proc `+`*(ti1, ti2: TimeInterval): TimeInterval =
 
 proc `-`*(ti: TimeInterval): TimeInterval =
   ## Reverses a time interval
-  ##
-  ## .. code-block:: nim
-  ##
-  ##     let day = -initInterval(hours=24)
-  ##     echo day  # -> (milliseconds: 0, seconds: 0, minutes: 0, hours: -24, days: 0, months: 0, years: 0)
+  runnableExamples:
+    let day = -initTimeInterval(hours=24)
+    doAssert day.hours == -24
+
   result = TimeInterval(
     nanoseconds: -ti.nanoseconds,
     microseconds: -ti.microseconds,
@@ -939,13 +984,10 @@ proc `-`*(ti1, ti2: TimeInterval): TimeInterval =
   ## Subtracts TimeInterval ``ti1`` from ``ti2``.
   ##
   ## Time components are subtracted one-by-one, see output:
-  ##
-  ## .. code-block:: nim
-  ##     let a = fromUnix(1_000_000_000)
-  ##     let b = fromUnix(1_500_000_000)
-  ##     echo b.toTimeInterval - a.toTimeInterval
-  ##     # (nanoseconds: 0, microseconds: 0, milliseconds: 0, seconds: -40,
-  ##        minutes: -6, hours: 1, days: 5, weeks: 0, months: -2, years: 16)
+  runnableExamples:
+    let ti1 = initTimeInterval(hours=24)
+    let ti2 = initTimeInterval(hours=4)
+    doAssert (ti1 - ti2) == initTimeInterval(hours=20)
 
   result = ti1 + (-ti2)
 
@@ -974,6 +1016,37 @@ proc `$`*(m: Month): string =
       "November", "December"]
   return lookup[m]
 
+
+proc toParts* (ti: TimeInterval): TimeIntervalParts =
+  ## Converts a `TimeInterval` into an array consisting of its time units,
+  ## starting with nanoseconds and ending with years
+  ##
+  ## This procedure is useful for converting ``TimeInterval`` values to strings.
+  ## E.g. then you need to implement custom interval printing
+  runnableExamples:
+    var tp = toParts(initTimeInterval(years=1, nanoseconds=123))
+    doAssert tp[Years] == 1
+    doAssert tp[Nanoseconds] == 123
+
+  var index = 0
+  for name, value in fieldPairs(ti):
+    result[index.TimeUnit()] = value
+    index += 1
+
+proc `$`*(ti: TimeInterval): string =
+  ## Get string representation of `TimeInterval`
+  runnableExamples:
+    doAssert $initTimeInterval(years=1, nanoseconds=123) == "1 year and 123 nanoseconds"
+    doAssert $initTimeInterval() == "0 nanoseconds"
+
+  var parts: seq[string] = @[]
+  var tiParts = toParts(ti)
+  for unit in countdown(Years, Nanoseconds):
+    if tiParts[unit] != 0:
+      parts.add(stringifyUnit(tiParts[unit], $unit))
+
+  result = humanizeParts(parts)
+
 proc nanoseconds*(nanos: int): TimeInterval {.inline.} =
   ## TimeInterval of ``nanos`` nanoseconds.
   initTimeInterval(nanoseconds = nanos)
@@ -1067,6 +1140,37 @@ proc evaluateInterval(dt: DateTime, interval: TimeInterval): tuple[adjDur, absDu
     minutes = interval.minutes,
     hours = interval.hours)
 
+
+proc initDateTime*(monthday: MonthdayRange, month: Month, year: int,
+                   hour: HourRange, minute: MinuteRange, second: SecondRange,
+                   nanosecond: NanosecondRange, zone: Timezone = local()): DateTime =
+  ## Create a new ``DateTime`` in the specified timezone.
+  runnableExamples:
+    let dt1 = initDateTime(30, mMar, 2017, 00, 00, 00, 00, utc())
+    doAssert $dt1 == "2017-03-30T00:00:00+00:00"
+
+  assertValidDate monthday, month, year
+  let dt = DateTime(
+    monthday:  monthday,
+    year:  year,
+    month:  month,
+    hour:  hour,
+    minute:  minute,
+    second:  second,
+    nanosecond: nanosecond
+  )
+  result = initDateTime(zone.zoneInfoFromTz(dt.toAdjTime), zone)
+
+proc initDateTime*(monthday: MonthdayRange, month: Month, year: int,
+                   hour: HourRange, minute: MinuteRange, second: SecondRange,
+                   zone: Timezone = local()): DateTime =
+  ## Create a new ``DateTime`` in the specified timezone.
+  runnableExamples:
+    let dt1 = initDateTime(30, mMar, 2017, 00, 00, 00, utc())
+    doAssert $dt1 == "2017-03-30T00:00:00+00:00"
+  initDateTime(monthday, month, year, hour, minute, second, 0, zone)
+
+
 proc `+`*(dt: DateTime, interval: TimeInterval): DateTime =
   ## Adds ``interval`` to ``dt``. Components from ``interval`` are added
   ## in the order of their size, i.e first the ``years`` component, then the ``months``
@@ -1100,14 +1204,51 @@ proc `-`*(dt: DateTime, interval: TimeInterval): DateTime =
   ## Subtract ``interval`` from ``dt``. Components from ``interval`` are subtracted
   ## in the order of their size, i.e first the ``years`` component, then the ``months``
   ## component and so on. The returned ``DateTime`` will have the same timezone as the input.
+  runnableExamples:
+    let dt = initDateTime(30, mMar, 2017, 00, 00, 00, utc())
+    doAssert $(dt - 5.days) == "2017-03-25T00:00:00+00:00"
+
   dt + (-interval)
 
 proc `+`*(dt: DateTime, dur: Duration): DateTime =
+  runnableExamples:
+    let dt = initDateTime(30, mMar, 2017, 00, 00, 00, utc())
+    let dur = initDuration(hours = 5)
+    doAssert $(dt + dur) == "2017-03-30T05:00:00+00:00"
+
   (dt.toTime + dur).inZone(dt.timezone)
 
 proc `-`*(dt: DateTime, dur: Duration): DateTime =
+  runnableExamples:
+    let dt = initDateTime(30, mMar, 2017, 00, 00, 00, utc())
+    let dur = initDuration(days = 5)
+    doAssert $(dt - dur) == "2017-03-25T00:00:00+00:00"
+
   (dt.toTime - dur).inZone(dt.timezone)
 
+proc `-`*(dt1, dt2: DateTime): Duration =
+  ## Compute the duration between ``dt1`` and ``dt2``.
+  runnableExamples:
+    let dt1 = initDateTime(30, mMar, 2017, 00, 00, 00, utc())
+    let dt2 = initDateTime(25, mMar, 2017, 00, 00, 00, utc())
+
+    doAssert dt1 - dt2 == initDuration(days = 5)
+
+  dt1.toTime - dt2.toTime
+
+proc `<`*(a, b: DateTime): bool =
+  ## Returns true iff ``a < b``, that is iff a happened before b.
+  return a.toTime < b.toTime
+
+proc `<=` * (a, b: DateTime): bool =
+  ## Returns true iff ``a <= b``.
+  return a.toTime <= b.toTime
+
+proc `==`*(a, b: DateTime): bool =
+  ## Returns true if ``a == b``, that is if both dates represent the same point in datetime.
+  return a.toTime == b.toTime
+
+
 proc isStaticInterval(interval: TimeInterval): bool =
   interval.years == 0 and interval.months == 0 and
     interval.days == 0 and interval.weeks == 0
@@ -1121,12 +1262,116 @@ proc evaluateStaticInterval(interval: TimeInterval): Duration =
     minutes = interval.minutes,
     hours = interval.hours)
 
+proc between*(startDt, endDt:DateTime): TimeInterval =
+  ## Evaluate difference between two dates in ``TimeInterval`` format, so, it
+  ## will be relative.
+  ##
+  ## **Warning:** It's not recommended to use ``between`` for ``DateTime's`` in 
+  ## different ``TimeZone's``.  
+  ## ``a + between(a, b) == b`` is only guaranteed when ``a`` and ``b`` are in UTC.
+  runnableExamples:
+    var a = initDateTime(year = 2018, month = Month(3), monthday = 25, 
+                     hour = 0, minute = 59, second = 59, nanosecond = 1,
+                     zone = utc()).local
+    var b = initDateTime(year = 2018, month = Month(3), monthday = 25, 
+                     hour = 1, minute =  1, second =  1, nanosecond = 0,
+                     zone = utc()).local
+    doAssert between(a, b) == initTimeInterval(
+      nanoseconds=999, milliseconds=999, microseconds=999, seconds=1, minutes=1)
+    
+    a = parse("2018-01-09T00:00:00+00:00", "yyyy-MM-dd'T'HH:mm:sszzz", utc())
+    b = parse("2018-01-10T23:00:00-02:00", "yyyy-MM-dd'T'HH:mm:sszzz")
+    doAssert between(a, b) == initTimeInterval(hours=1, days=2)
+    ## Though, here correct answer should be 1 day 25 hours (cause this day in
+    ## this tz is actually 26 hours). That's why operating different TZ is
+    ## discouraged
+
+  var startDt = startDt.utc()
+  var endDt = endDt.utc()
+
+  if endDt == startDt:
+    return initTimeInterval()
+  elif endDt < startDt:
+    return -between(endDt, startDt)
+
+  var coeffs: array[FixedTimeUnit, int64] = unitWeights
+  var timeParts: array[FixedTimeUnit, int]
+  for unit in Nanoseconds..Weeks:
+    timeParts[unit] = 0
+
+  for unit in Seconds..Days:
+    coeffs[unit] = coeffs[unit] div unitWeights[Seconds]
+
+  var startTimepart = initTime(
+    nanosecond = startDt.nanosecond,
+    unix = startDt.hour * coeffs[Hours] + startDt.minute * coeffs[Minutes] +
+    startDt.second
+  )
+  var endTimepart = initTime(
+    nanosecond = endDt.nanosecond,
+    unix = endDt.hour * coeffs[Hours] + endDt.minute * coeffs[Minutes] +
+    endDt.second
+  )
+  # We wand timeParts for Seconds..Hours be positive, so we'll borrow one day
+  if endTimepart < startTimepart:
+    timeParts[Days] = -1
+
+  let diffTime = endTimepart - startTimepart
+  timeParts[Seconds] = diffTime.seconds.int()
+  #Nanoseconds - preliminary count
+  timeParts[Nanoseconds] = diffTime.nanoseconds
+  for unit in countdown(Milliseconds, Microseconds):
+    timeParts[unit] += timeParts[Nanoseconds] div coeffs[unit].int()
+    timeParts[Nanoseconds] -= timeParts[unit] * coeffs[unit].int()
+
+  #Counting Seconds .. Hours - final, Days - preliminary
+  for unit in countdown(Days, Minutes):
+    timeParts[unit] += timeParts[Seconds] div coeffs[unit].int()
+    # Here is accounted the borrowed day
+    timeParts[Seconds] -= timeParts[unit] * coeffs[unit].int()
+
+  # Set Nanoseconds .. Hours in result
+  result.nanoseconds = timeParts[Nanoseconds]
+  result.microseconds = timeParts[Microseconds]
+  result.milliseconds = timeParts[Milliseconds]
+  result.seconds = timeParts[Seconds]
+  result.minutes = timeParts[Minutes]
+  result.hours = timeParts[Hours]
+
+  #Days
+  if endDt.monthday.int + timeParts[Days] < startDt.monthday.int():
+    if endDt.month > 1.Month:
+      endDt.month -= 1.Month
+    else:
+      endDt.month = 12.Month
+      endDt.year -= 1
+    timeParts[Days] += endDt.monthday.int() + getDaysInMonth(
+      endDt.month, endDt.year) - startDt.monthday.int()
+  else:
+    timeParts[Days] += endDt.monthday.int() -
+      startDt.monthday.int()
+
+  result.days = timeParts[Days]
+
+  #Months
+  if endDt.month < startDt.month:
+      result.months = endDt.month.int() + 12 - startDt.month.int()
+      endDt.year -= 1
+  else:
+    result.months = endDt.month.int() -
+      startDt.month.int()
+
+  # Years
+  result.years = endDt.year - startDt.year
+
 proc `+`*(time: Time, interval: TimeInterval): Time =
   ## Adds `interval` to `time`.
   ## If `interval` contains any years, months, weeks or days the operation
   ## is performed in the local timezone.
-  ##
-  ## ``echo getTime() + 1.day``
+  runnableExamples:
+    let tm = fromUnix(0)
+    doAssert tm + 5.seconds == fromUnix(5)
+
   if interval.isStaticInterval:
     time + evaluateStaticInterval(interval)
   else:
@@ -1136,14 +1381,21 @@ proc `+=`*(time: var Time, interval: TimeInterval) =
   ## Modifies `time` by adding `interval`.
   ## If `interval` contains any years, months, weeks or days the operation
   ## is performed in the local timezone.
+  runnableExamples:
+    var tm = fromUnix(0)
+    tm += 5.seconds
+    doAssert tm == fromUnix(5)
+
   time = time + interval
 
 proc `-`*(time: Time, interval: TimeInterval): Time =
   ## Subtracts `interval` from Time `time`.
   ## If `interval` contains any years, months, weeks or days the operation
   ## is performed in the local timezone.
-  ##
-  ## ``echo getTime() - 1.day``
+  runnableExamples:
+    let tm = fromUnix(5)
+    doAssert tm - 5.seconds == fromUnix(0)
+
   if interval.isStaticInterval:
     time - evaluateStaticInterval(interval)
   else:
@@ -1153,6 +1405,10 @@ proc `-=`*(time: var Time, interval: TimeInterval) =
   ## Modifies `time` by subtracting `interval`.
   ## If `interval` contains any years, months, weeks or days the operation
   ## is performed in the local timezone.
+  runnableExamples:
+    var tm = fromUnix(5)
+    tm -= 5.seconds
+    doAssert tm == fromUnix(0)
   time = time - interval
 
 proc formatToken(dt: DateTime, token: string, buf: var string) =
@@ -1274,6 +1530,12 @@ proc formatToken(dt: DateTime, token: string, buf: var string) =
     buf.add(':')
     if minutes < 10: buf.add('0')
     buf.add($minutes)
+  of "fff":
+    buf.add(intToStr(convert(Nanoseconds, Milliseconds, dt.nanosecond), 3))
+  of "ffffff":
+    buf.add(intToStr(convert(Nanoseconds, Microseconds, dt.nanosecond), 6))
+  of "fffffffff":
+    buf.add(intToStr(dt.nanosecond, 9))
   of "":
     discard
   else:
@@ -1284,40 +1546,46 @@ proc format*(dt: DateTime, f: string): string {.tags: [].}=
   ## This procedure formats `dt` as specified by `f`. The following format
   ## specifiers are available:
   ##
-  ## ==========  =================================================================================  ================================================
-  ## Specifier   Description                                                                        Example
-  ## ==========  =================================================================================  ================================================
-  ##    d        Numeric value of the day of the month, it will be one or two digits long.          ``1/04/2012 -> 1``, ``21/04/2012 -> 21``
-  ##    dd       Same as above, but always two digits.                                              ``1/04/2012 -> 01``, ``21/04/2012 -> 21``
-  ##    ddd      Three letter string which indicates the day of the week.                           ``Saturday -> Sat``, ``Monday -> Mon``
-  ##    dddd     Full string for the day of the week.                                               ``Saturday -> Saturday``, ``Monday -> Monday``
-  ##    h        The hours in one digit if possible. Ranging from 0-12.                             ``5pm -> 5``, ``2am -> 2``
-  ##    hh       The hours in two digits always. If the hour is one digit 0 is prepended.           ``5pm -> 05``, ``11am -> 11``
-  ##    H        The hours in one digit if possible, randing from 0-24.                             ``5pm -> 17``, ``2am -> 2``
-  ##    HH       The hours in two digits always. 0 is prepended if the hour is one digit.           ``5pm -> 17``, ``2am -> 02``
-  ##    m        The minutes in 1 digit if possible.                                                ``5:30 -> 30``, ``2:01 -> 1``
-  ##    mm       Same as above but always 2 digits, 0 is prepended if the minute is one digit.      ``5:30 -> 30``, ``2:01 -> 01``
-  ##    M        The month in one digit if possible.                                                ``September -> 9``, ``December -> 12``
-  ##    MM       The month in two digits always. 0 is prepended.                                    ``September -> 09``, ``December -> 12``
-  ##    MMM      Abbreviated three-letter form of the month.                                        ``September -> Sep``, ``December -> Dec``
-  ##    MMMM     Full month string, properly capitalized.                                           ``September -> September``
-  ##    s        Seconds as one digit if possible.                                                  ``00:00:06 -> 6``
-  ##    ss       Same as above but always two digits. 0 is prepended.                               ``00:00:06 -> 06``
-  ##    t        ``A`` when time is in the AM. ``P`` when time is in the PM.
-  ##    tt       Same as above, but ``AM`` and ``PM`` instead of ``A`` and ``P`` respectively.
-  ##    y(yyyy)  This displays the year to different digits. You most likely only want 2 or 4 'y's
-  ##    yy       Displays the year to two digits.                                                   ``2012 -> 12``
-  ##    yyyy     Displays the year to four digits.                                                  ``2012 -> 2012``
-  ##    z        Displays the timezone offset from UTC.                                             ``GMT+7 -> +7``, ``GMT-5 -> -5``
-  ##    zz       Same as above but with leading 0.                                                  ``GMT+7 -> +07``, ``GMT-5 -> -05``
-  ##    zzz      Same as above but with ``:mm`` where *mm* represents minutes.                      ``GMT+7 -> +07:00``, ``GMT-5 -> -05:00``
-  ## ==========  =================================================================================  ================================================
+  ## ============  =================================================================================  ================================================
+  ## Specifier     Description                                                                        Example
+  ## ============  =================================================================================  ================================================
+  ##    d          Numeric value of the day of the month, it will be one or two digits long.          ``1/04/2012 -> 1``, ``21/04/2012 -> 21``
+  ##    dd         Same as above, but always two digits.                                              ``1/04/2012 -> 01``, ``21/04/2012 -> 21``
+  ##    ddd        Three letter string which indicates the day of the week.                           ``Saturday -> Sat``, ``Monday -> Mon``
+  ##    dddd       Full string for the day of the week.                                               ``Saturday -> Saturday``, ``Monday -> Monday``
+  ##    h          The hours in one digit if possible. Ranging from 0-12.                             ``5pm -> 5``, ``2am -> 2``
+  ##    hh         The hours in two digits always. If the hour is one digit 0 is prepended.           ``5pm -> 05``, ``11am -> 11``
+  ##    H          The hours in one digit if possible, randing from 0-24.                             ``5pm -> 17``, ``2am -> 2``
+  ##    HH         The hours in two digits always. 0 is prepended if the hour is one digit.           ``5pm -> 17``, ``2am -> 02``
+  ##    m          The minutes in 1 digit if possible.                                                ``5:30 -> 30``, ``2:01 -> 1``
+  ##    mm         Same as above but always 2 digits, 0 is prepended if the minute is one digit.      ``5:30 -> 30``, ``2:01 -> 01``
+  ##    M          The month in one digit if possible.                                                ``September -> 9``, ``December -> 12``
+  ##    MM         The month in two digits always. 0 is prepended.                                    ``September -> 09``, ``December -> 12``
+  ##    MMM        Abbreviated three-letter form of the month.                                        ``September -> Sep``, ``December -> Dec``
+  ##    MMMM       Full month string, properly capitalized.                                           ``September -> September``
+  ##    s          Seconds as one digit if possible.                                                  ``00:00:06 -> 6``
+  ##    ss         Same as above but always two digits. 0 is prepended.                               ``00:00:06 -> 06``
+  ##    t          ``A`` when time is in the AM. ``P`` when time is in the PM.
+  ##    tt         Same as above, but ``AM`` and ``PM`` instead of ``A`` and ``P`` respectively.
+  ##    y(yyyy)    This displays the year to different digits. You most likely only want 2 or 4 'y's
+  ##    yy         Displays the year to two digits.                                                   ``2012 -> 12``
+  ##    yyyy       Displays the year to four digits.                                                  ``2012 -> 2012``
+  ##    z          Displays the timezone offset from UTC.                                             ``GMT+7 -> +7``, ``GMT-5 -> -5``
+  ##    zz         Same as above but with leading 0.                                                  ``GMT+7 -> +07``, ``GMT-5 -> -05``
+  ##    zzz        Same as above but with ``:mm`` where *mm* represents minutes.                      ``GMT+7 -> +07:00``, ``GMT-5 -> -05:00``
+  ##    fff        Milliseconds display                                                               ``1000000 nanoseconds -> 1``
+  ##    ffffff     Microseconds display                                                               ``1000000 nanoseconds -> 1000``
+  ##    fffffffff  Nanoseconds display                                                                ``1000000 nanoseconds -> 1000000``
+  ## ============  =================================================================================  ================================================
   ##
   ## Other strings can be inserted by putting them in ``''``. For example
   ## ``hh'->'mm`` will give ``01->56``.  The following characters can be
   ## inserted without quoting them: ``:`` ``-`` ``(`` ``)`` ``/`` ``[`` ``]``
   ## ``,``. However you don't need to necessarily separate format specifiers, a
   ## unambiguous format string like ``yyyyMMddhhmmss`` is valid too.
+  runnableExamples:
+    let dt = initDateTime(01, mJan, 2000, 12, 00, 00, 01, utc())
+    doAssert format(dt, "yyyy-MM-dd'T'HH:mm:ss'.'fffffffffzzz") == "2000-01-01T12:00:00.000000001+00:00"
 
   result = ""
   var i = 0
@@ -1348,9 +1616,25 @@ proc format*(dt: DateTime, f: string): string {.tags: [].}=
     inc(i)
   formatToken(dt, currentF, result)
 
+proc format*(time: Time, f: string, zone_info: proc(t: Time): DateTime): string {.tags: [].} =
+  ## converts a `Time` value to a string representation. It will use format from
+  ## ``format(dt: DateTime, f: string)``.
+  runnableExamples:
+    var dt = initDateTime(01, mJan, 1970, 00, 00, 00, local())
+    var tm = dt.toTime()
+    doAssert format(tm, "yyyy-MM-dd'T'HH:mm:ss", local) == "1970-01-01T00:00:00"
+    dt = initDateTime(01, mJan, 1970, 00, 00, 00, utc())
+    tm = dt.toTime()
+    doAssert format(tm, "yyyy-MM-dd'T'HH:mm:ss", utc) == "1970-01-01T00:00:00"
+
+  zone_info(time).format(f)
+
 proc `$`*(dt: DateTime): string {.tags: [], raises: [], benign.} =
   ## Converts a `DateTime` object to a string representation.
   ## It uses the format ``yyyy-MM-dd'T'HH-mm-sszzz``.
+  runnableExamples:
+    let dt = initDateTime(01, mJan, 2000, 12, 00, 00, utc())
+    doAssert $dt == "2000-01-01T12:00:00+00:00"
   try:
     result = format(dt, "yyyy-MM-dd'T'HH:mm:sszzz") # todo: optimize this
   except ValueError: assert false # cannot happen because format string is valid
@@ -1358,6 +1642,10 @@ proc `$`*(dt: DateTime): string {.tags: [], raises: [], benign.} =
 proc `$`*(time: Time): string {.tags: [], raises: [], benign.} =
   ## converts a `Time` value to a string representation. It will use the local
   ## time zone and use the format ``yyyy-MM-dd'T'HH-mm-sszzz``.
+  runnableExamples:
+    let dt = initDateTime(01, mJan, 1970, 00, 00, 00, local())
+    let tm = dt.toTime()
+    doAssert $tm == "1970-01-01T00:00:00" & format(dt, "zzz")
   $time.local
 
 {.pop.}
@@ -1574,6 +1862,11 @@ proc parseToken(dt: var DateTime; token, value: string; j: var int) =
     j += 4
     dt.utcOffset += factor * value[j..j+1].parseInt() * 60
     j += 2
+  of "fff", "ffffff", "fffffffff":
+    var numStr = ""
+    let n = parseWhile(value[j..len(value) - 1], numStr, {'0'..'9'})
+    dt.nanosecond = parseInt(numStr) * (10 ^ (9 - n))
+    j += n
   else:
     # Ignore the token and move forward in the value string by the same length
     j += token.len
@@ -1587,39 +1880,44 @@ proc parse*(value, layout: string, zone: Timezone = local()): DateTime =
   ## parsed, then the input will be assumed to be specified in the `zone` timezone
   ## already, so no timezone conversion will be done in that case.
   ##
-  ## ==========  =================================================================================  ================================================
-  ## Specifier   Description                                                                        Example
-  ## ==========  =================================================================================  ================================================
-  ##    d        Numeric value of the day of the month, it will be one or two digits long.          ``1/04/2012 -> 1``, ``21/04/2012 -> 21``
-  ##    dd       Same as above, but always two digits.                                              ``1/04/2012 -> 01``, ``21/04/2012 -> 21``
-  ##    ddd      Three letter string which indicates the day of the week.                           ``Saturday -> Sat``, ``Monday -> Mon``
-  ##    dddd     Full string for the day of the week.                                               ``Saturday -> Saturday``, ``Monday -> Monday``
-  ##    h        The hours in one digit if possible. Ranging from 0-12.                             ``5pm -> 5``, ``2am -> 2``
-  ##    hh       The hours in two digits always. If the hour is one digit 0 is prepended.           ``5pm -> 05``, ``11am -> 11``
-  ##    H        The hours in one digit if possible, randing from 0-24.                             ``5pm -> 17``, ``2am -> 2``
-  ##    HH       The hours in two digits always. 0 is prepended if the hour is one digit.           ``5pm -> 17``, ``2am -> 02``
-  ##    m        The minutes in 1 digit if possible.                                                ``5:30 -> 30``, ``2:01 -> 1``
-  ##    mm       Same as above but always 2 digits, 0 is prepended if the minute is one digit.      ``5:30 -> 30``, ``2:01 -> 01``
-  ##    M        The month in one digit if possible.                                                ``September -> 9``, ``December -> 12``
-  ##    MM       The month in two digits always. 0 is prepended.                                    ``September -> 09``, ``December -> 12``
-  ##    MMM      Abbreviated three-letter form of the month.                                        ``September -> Sep``, ``December -> Dec``
-  ##    MMMM     Full month string, properly capitalized.                                           ``September -> September``
-  ##    s        Seconds as one digit if possible.                                                  ``00:00:06 -> 6``
-  ##    ss       Same as above but always two digits. 0 is prepended.                               ``00:00:06 -> 06``
-  ##    t        ``A`` when time is in the AM. ``P`` when time is in the PM.
-  ##    tt       Same as above, but ``AM`` and ``PM`` instead of ``A`` and ``P`` respectively.
-  ##    yy       Displays the year to two digits.                                                   ``2012 -> 12``
-  ##    yyyy     Displays the year to four digits.                                                  ``2012 -> 2012``
-  ##    z        Displays the timezone offset from UTC. ``Z`` is parsed as ``+0``                   ``GMT+7 -> +7``, ``GMT-5 -> -5``
-  ##    zz       Same as above but with leading 0.                                                  ``GMT+7 -> +07``, ``GMT-5 -> -05``
-  ##    zzz      Same as above but with ``:mm`` where *mm* represents minutes.                      ``GMT+7 -> +07:00``, ``GMT-5 -> -05:00``
-  ## ==========  =================================================================================  ================================================
+  ## =======================  =================================================================================  ================================================
+  ## Specifier                Description                                                                        Example
+  ## =======================  =================================================================================  ================================================
+  ##    d                     Numeric value of the day of the month, it will be one or two digits long.          ``1/04/2012 -> 1``, ``21/04/2012 -> 21``
+  ##    dd                    Same as above, but always two digits.                                              ``1/04/2012 -> 01``, ``21/04/2012 -> 21``
+  ##    ddd                   Three letter string which indicates the day of the week.                           ``Saturday -> Sat``, ``Monday -> Mon``
+  ##    dddd                  Full string for the day of the week.                                               ``Saturday -> Saturday``, ``Monday -> Monday``
+  ##    h                     The hours in one digit if possible. Ranging from 0-12.                             ``5pm -> 5``, ``2am -> 2``
+  ##    hh                    The hours in two digits always. If the hour is one digit 0 is prepended.           ``5pm -> 05``, ``11am -> 11``
+  ##    H                     The hours in one digit if possible, randing from 0-24.                             ``5pm -> 17``, ``2am -> 2``
+  ##    HH                    The hours in two digits always. 0 is prepended if the hour is one digit.           ``5pm -> 17``, ``2am -> 02``
+  ##    m                     The minutes in 1 digit if possible.                                                ``5:30 -> 30``, ``2:01 -> 1``
+  ##    mm                    Same as above but always 2 digits, 0 is prepended if the minute is one digit.      ``5:30 -> 30``, ``2:01 -> 01``
+  ##    M                     The month in one digit if possible.                                                ``September -> 9``, ``December -> 12``
+  ##    MM                    The month in two digits always. 0 is prepended.                                    ``September -> 09``, ``December -> 12``
+  ##    MMM                   Abbreviated three-letter form of the month.                                        ``September -> Sep``, ``December -> Dec``
+  ##    MMMM                  Full month string, properly capitalized.                                           ``September -> September``
+  ##    s                     Seconds as one digit if possible.                                                  ``00:00:06 -> 6``
+  ##    ss                    Same as above but always two digits. 0 is prepended.                               ``00:00:06 -> 06``
+  ##    t                     ``A`` when time is in the AM. ``P`` when time is in the PM.
+  ##    tt                    Same as above, but ``AM`` and ``PM`` instead of ``A`` and ``P`` respectively.
+  ##    yy                    Displays the year to two digits.                                                   ``2012 -> 12``
+  ##    yyyy                  Displays the year to four digits.                                                  ``2012 -> 2012``
+  ##    z                     Displays the timezone offset from UTC. ``Z`` is parsed as ``+0``                   ``GMT+7 -> +7``, ``GMT-5 -> -5``
+  ##    zz                    Same as above but with leading 0.                                                  ``GMT+7 -> +07``, ``GMT-5 -> -05``
+  ##    zzz                   Same as above but with ``:mm`` where *mm* represents minutes.                      ``GMT+7 -> +07:00``, ``GMT-5 -> -05:00``
+  ##    fff/ffffff/fffffffff  for consistency with format - nanoseconds                                          ``1 -> 1 nanosecond``
+  ## =======================  =================================================================================  ================================================
   ##
   ## Other strings can be inserted by putting them in ``''``. For example
   ## ``hh'->'mm`` will give ``01->56``.  The following characters can be
   ## inserted without quoting them: ``:`` ``-`` ``(`` ``)`` ``/`` ``[`` ``]``
   ## ``,``. However you don't need to necessarily separate format specifiers, a
   ## unambiguous format string like ``yyyyMMddhhmmss`` is valid too.
+  runnableExamples:
+    let tStr = "1970-01-01T00:00:00.0+00:00"
+    doAssert parse(tStr, "yyyy-MM-dd'T'HH:mm:ss.fffzzz") == fromUnix(0).utc
+
   var i = 0 # pointer for format string
   var j = 0 # pointer for value string
   var token = ""
@@ -1667,6 +1965,13 @@ proc parse*(value, layout: string, zone: Timezone = local()): DateTime =
     # Otherwise convert to `zone`
     result = dt.toTime.inZone(zone)
 
+proc parseTime*(value, layout: string, zone: Timezone): Time =
+  ## Simple wrapper for parsing string to time
+  runnableExamples:
+    let tStr = "1970-01-01T00:00:00+00:00"
+    doAssert parseTime(tStr, "yyyy-MM-dd'T'HH:mm:sszzz", local()) == fromUnix(0)
+  parse(value, layout, zone).toTime()
+
 proc countLeapYears*(yearSpan: int): int =
   ## Returns the number of leap years spanned by a given number of years.
   ##
@@ -1695,41 +2000,19 @@ proc toTimeInterval*(time: Time): TimeInterval =
   ## Converts a Time to a TimeInterval.
   ##
   ## To be used when diffing times.
-  ##
-  ## .. code-block:: nim
-  ##     let a = fromSeconds(1_000_000_000)
-  ##     let b = fromSeconds(1_500_000_000)
-  ##     echo a, " ", b  # real dates
-  ##     echo a.toTimeInterval  # meaningless value, don't use it by itself
-  ##     echo b.toTimeInterval - a.toTimeInterval
-  ##     # (nanoseconds: 0, microseconds: 0, milliseconds: 0, seconds: -40,
-  ##        minutes: -6, hours: 1, days: 5, weeks: 0, months: -2, years: 16)
+  runnableExamples:
+    let a = fromUnix(10)
+    let dt = initDateTime(01, mJan, 1970, 00, 00, 00, local())
+    doAssert a.toTimeInterval() == initTimeInterval(
+      years=1970, days=1, seconds=10, hours=convert(
+        Seconds, Hours, -dt.utcOffset
+      )
+    )
+
   var dt = time.local
   initTimeInterval(dt.nanosecond, 0, 0, dt.second, dt.minute, dt.hour,
     dt.monthday, 0, dt.month.ord - 1, dt.year)
 
-proc initDateTime*(monthday: MonthdayRange, month: Month, year: int,
-                   hour: HourRange, minute: MinuteRange, second: SecondRange,
-                   nanosecond: NanosecondRange, zone: Timezone = local()): DateTime =
-  ## Create a new ``DateTime`` in the specified timezone.
-  assertValidDate monthday, month, year
-  let dt = DateTime(
-    monthday:  monthday,
-    year:  year,
-    month:  month,
-    hour:  hour,
-    minute:  minute,
-    second:  second,
-    nanosecond: nanosecond
-  )
-  result = initDateTime(zone.zoneInfoFromTz(dt.toAdjTime), zone)
-
-proc initDateTime*(monthday: MonthdayRange, month: Month, year: int,
-                   hour: HourRange, minute: MinuteRange, second: SecondRange,
-                   zone: Timezone = local()): DateTime =
-  ## Create a new ``DateTime`` in the specified timezone.
-  initDateTime(monthday, month, year, hour, minute, second, 0, zone)
-
 when not defined(JS):
   type
     Clock {.importc: "clock_t".} = distinct int
@@ -1747,11 +2030,14 @@ when not defined(JS):
       ## The value of the result has no meaning.
       ## To generate useful timing values, take the difference between
       ## the results of two ``cpuTime`` calls:
-      ##
-      ## .. code-block:: nim
-      ##   var t0 = cpuTime()
-      ##   doWork()
-      ##   echo "CPU time [s] ", cpuTime() - t0
+      runnableExamples:
+        var t0 = cpuTime()
+        # some useless work here (calculate fibonacci)
+        var fib = @[0, 1, 1]
+        for i in 1..10:
+          fib.add(fib[^1] + fib[^2])
+        echo "CPU time [s] ", cpuTime() - t0
+        echo "Fib is [s] ", fib
       result = toFloat(int(getClock())) / toFloat(clocksPerSec)
 
     proc epochTime*(): float {.rtl, extern: "nt$1", tags: [TimeEffect].} =
@@ -1853,15 +2139,14 @@ proc getTimezone*(): int {.tags: [TimeEffect], raises: [], benign, deprecated.}
 proc timeInfoToTime*(dt: DateTime): Time {.tags: [], benign, deprecated.} =
   ## Converts a broken-down time structure to calendar time representation.
   ##
-  ## **Warning:** This procedure is deprecated since version 0.14.0.
-  ## Use ``toTime`` instead.
+  ## **Deprecated since v0.14.0:** use ``toTime`` instead.
   dt.toTime
 
 when defined(JS):
   var start = getTime()
   proc getStartMilsecs*(): int {.deprecated, tags: [TimeEffect], benign.} =
-    ## get the milliseconds from the start of the program. **Deprecated since
-    ## version 0.8.10.** Use ``epochTime`` or ``cpuTime`` instead.
+    ## get the milliseconds from the start of the program.
+    ## **Deprecated since v0.8.10:** use ``epochTime`` or ``cpuTime`` instead.
     let dur = getTime() - start
     result = (convert(Seconds, Milliseconds, dur.seconds) +
       convert(Nanoseconds, Milliseconds, dur.nanosecond)).int
@@ -1875,19 +2160,19 @@ else:
 proc timeToTimeInterval*(t: Time): TimeInterval {.deprecated.} =
   ## Converts a Time to a TimeInterval.
   ##
-  ## **Warning:** This procedure is deprecated since version 0.14.0.
-  ## Use ``toTimeInterval`` instead.
+  ## **Deprecated since v0.14.0:** use ``toTimeInterval`` instead.
   # Milliseconds not available from Time
   t.toTimeInterval()
 
 proc getDayOfWeek*(day, month, year: int): WeekDay  {.tags: [], raises: [], benign, deprecated.} =
-  ## **Warning:** This procedure is deprecated since version 0.18.0.
+  ## **Deprecated since v0.18.0:** use 
+  ## ``getDayOfWeek(monthday: MonthdayRange; month: Month; year: int)`` instead.
   getDayOfWeek(day, month.Month, year)
 
 proc getDayOfWeekJulian*(day, month, year: int): WeekDay {.deprecated.} =
   ## Returns the day of the week enum from day, month and year,
   ## according to the Julian calendar.
-  ## **Warning:** This procedure is deprecated since version 0.18.0.
+  ## **Deprecated since v0.18.0:**
   # Day & month start from one.
   let
     a = (14 - month) div 12
diff --git a/lib/pure/unicode.nim b/lib/pure/unicode.nim
index cc4d28f5b..bfd01be55 100644
--- a/lib/pure/unicode.nim
+++ b/lib/pure/unicode.nim
@@ -1826,8 +1826,8 @@ when isMainModule:
   doAssert(runeSubStr(s, 17, 1) == "€")
   # echo runeStrAtPos(s, 18) # index error
 
-  doAssert(runeSubStr(s, 0) ==  "Hänsel  ««: 10,00€")
-  doAssert(runeSubStr(s, -18) ==  "Hänsel  ««: 10,00€")
+  doAssert(runeSubStr(s, 0) == "Hänsel  ««: 10,00€")
+  doAssert(runeSubStr(s, -18) == "Hänsel  ««: 10,00€")
   doAssert(runeSubStr(s, 10) == ": 10,00€")
   doAssert(runeSubStr(s, 18) == "")
   doAssert(runeSubStr(s, 0, 10) == "Hänsel  ««")
@@ -1840,7 +1840,7 @@ when isMainModule:
   doAssert(runeSubStr(s, -6, 5) == "10,00")
   doAssert(runeSubStr(s, -6, -1) == "10,00")
 
-  doAssert(runeSubStr(s, 0, 100) ==  "Hänsel  ««: 10,00€")
-  doAssert(runeSubStr(s, -100, 100) ==  "Hänsel  ««: 10,00€")
+  doAssert(runeSubStr(s, 0, 100) == "Hänsel  ««: 10,00€")
+  doAssert(runeSubStr(s, -100, 100) == "Hänsel  ««: 10,00€")
   doAssert(runeSubStr(s, 0, -100) == "")
   doAssert(runeSubStr(s, 100, -100) == "")
diff --git a/lib/pure/unittest.nim b/lib/pure/unittest.nim
index 917251a6c..d804ba7c8 100644
--- a/lib/pure/unittest.nim
+++ b/lib/pure/unittest.nim
@@ -462,6 +462,8 @@ template suite*(name, body) {.dirty.} =
     finally:
       suiteEnded()
 
+template exceptionTypeName(e: typed): string = $e.name
+
 template test*(name, body) {.dirty.} =
   ## Define a single test case identified by `name`.
   ##
@@ -476,7 +478,7 @@ template test*(name, body) {.dirty.} =
   ## .. code-block::
   ##
   ##  [OK] roses are red
-  bind shouldRun, checkpoints, formatters, ensureInitialized, testEnded
+  bind shouldRun, checkpoints, formatters, ensureInitialized, testEnded, exceptionTypeName
 
   ensureInitialized()
 
@@ -495,8 +497,10 @@ template test*(name, body) {.dirty.} =
 
     except:
       when not defined(js):
-        checkpoint("Unhandled exception: " & getCurrentExceptionMsg())
-        var stackTrace {.inject.} = getCurrentException().getStackTrace()
+        let e = getCurrentException()
+        let eTypeDesc = "[" & exceptionTypeName(e) & "]"
+        checkpoint("Unhandled exception: " & getCurrentExceptionMsg() & " " & eTypeDesc)
+        var stackTrace {.inject.} = e.getStackTrace()
       fail()
 
     finally:
diff --git a/lib/pure/xmltree.nim b/lib/pure/xmltree.nim
index 8f85cb5c9..47658b59b 100644
--- a/lib/pure/xmltree.nim
+++ b/lib/pure/xmltree.nim
@@ -9,7 +9,7 @@
 
 ## A simple XML tree. More efficient and simpler than the DOM.
 
-import macros, strtabs
+import macros, strtabs, strutils
 
 type
   XmlNode* = ref XmlNodeObj ## an XML tree consists of ``XmlNode``'s.
@@ -217,8 +217,9 @@ proc escape*(s: string): string =
   result = newStringOfCap(s.len)
   addEscaped(result, s)
 
-proc addIndent(result: var string, indent: int) =
-  result.add("\n")
+proc addIndent(result: var string, indent: int, addNewLines: bool) =
+  if addNewLines:
+    result.add("\n")
   for i in 1..indent: result.add(' ')
 
 proc noWhitespace(n: XmlNode): bool =
@@ -227,7 +228,8 @@ proc noWhitespace(n: XmlNode): bool =
   for i in 0..n.len-1:
     if n[i].kind in {xnText, xnEntity}: return true
 
-proc add*(result: var string, n: XmlNode, indent = 0, indWidth = 2) =
+proc add*(result: var string, n: XmlNode, indent = 0, indWidth = 2,
+          addNewLines=true) =
   ## adds the textual representation of `n` to `result`.
 
   proc addEscapedAttr(result: var string, s: string) =
@@ -260,14 +262,15 @@ proc add*(result: var string, n: XmlNode, indent = 0, indWidth = 2) =
           # for mixed leaves, we cannot output whitespace for readability,
           # because this would be wrong. For example: ``a<b>b</b>`` is
           # different from ``a <b>b</b>``.
-          for i in 0..n.len-1: result.add(n[i], indent+indWidth, indWidth)
+          for i in 0..n.len-1:
+            result.add(n[i], indent+indWidth, indWidth, addNewLines)
         else:
           for i in 0..n.len-1:
-            result.addIndent(indent+indWidth)
-            result.add(n[i], indent+indWidth, indWidth)
-          result.addIndent(indent)
+            result.addIndent(indent+indWidth, addNewLines)
+            result.add(n[i], indent+indWidth, indWidth, addNewLines)
+          result.addIndent(indent, addNewLines)
       else:
-        result.add(n[0], indent+indWidth, indWidth)
+        result.add(n[0], indent+indWidth, indWidth, addNewLines)
       result.add("</")
       result.add(n.fTag)
       result.add(">")
@@ -316,7 +319,10 @@ proc xmlConstructor(a: NimNode): NimNode {.compileTime.} =
     var elements = newNimNode(nnkBracket, a)
     for i in 1..a.len-1:
       if a[i].kind == nnkExprEqExpr:
-        attrs.add(toStrLit(a[i][0]))
+        # In order to support attributes like `data-lang` we have to
+        # replace whitespace because `toStrLit` gives `data - lang`.
+        let attrName = toStrLit(a[i][0]).strVal.replace(" ", "")
+        attrs.add(newStrLitNode(attrName))
         attrs.add(a[i][1])
         #echo repr(attrs)
       else: