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-rw-r--r--lib/pure/logging.nim28
-rw-r--r--lib/pure/parseutils.nim30
-rw-r--r--lib/pure/strscans.nim521
-rw-r--r--lib/pure/strutils.nim2
4 files changed, 574 insertions, 7 deletions
diff --git a/lib/pure/logging.nim b/lib/pure/logging.nim
index f602ce31d..8a0d2fedd 100644
--- a/lib/pure/logging.nim
+++ b/lib/pure/logging.nim
@@ -54,6 +54,7 @@ type
     lvlAll,       ## all levels active
     lvlDebug,     ## debug level (and any above) active
     lvlInfo,      ## info level (and any above) active
+    lvlNotice,    ## info notice (and any above) active
     lvlWarn,      ## warn level (and any above) active
     lvlError,     ## error level (and any above) active
     lvlFatal,     ## fatal level (and any above) active
@@ -61,7 +62,7 @@ type
 
 const
   LevelNames*: array [Level, string] = [
-    "DEBUG", "DEBUG", "INFO", "WARN", "ERROR", "FATAL", "NONE"
+    "DEBUG", "DEBUG", "INFO", "NOTICE", "WARN", "ERROR", "FATAL", "NONE"
   ]
 
   defaultFmtStr* = "$levelname " ## default format string
@@ -258,22 +259,47 @@ template log*(level: Level, args: varargs[string, `$`]) =
 
 template debug*(args: varargs[string, `$`]) =
   ## Logs a debug message to all registered handlers.
+  ##
+  ## Messages that are useful to the application developer only and are usually
+  ## turned off in release.
   log(lvlDebug, args)
 
 template info*(args: varargs[string, `$`]) =
   ## Logs an info message to all registered handlers.
+  ##
+  ## Messages that are generated during the normal operation of an application
+  ## and are of no particular importance. Useful to aggregate for potential
+  ## later analysis.
   log(lvlInfo, args)
 
+template notice*(args: varargs[string, `$`]) =
+  ## Logs an notice message to all registered handlers.
+  ##
+  ## Semantically very similar to `info`, but meant to be messages you want to
+  ## be actively notified about (depending on your application).
+  ## These could be, for example, grouped by hour and mailed out.
+  log(lvlNotice, args)
+
 template warn*(args: varargs[string, `$`]) =
   ## Logs a warning message to all registered handlers.
+  ##
+  ## A non-error message that may indicate a potential problem rising or
+  ## impacted performance.
   log(lvlWarn, args)
 
 template error*(args: varargs[string, `$`]) =
   ## Logs an error message to all registered handlers.
+  ##
+  ## A application-level error condition. For example, some user input generated
+  ## an exception. The application will continue to run, but functionality or
+  ## data was impacted, possibly visible to users.
   log(lvlError, args)
 
 template fatal*(args: varargs[string, `$`]) =
   ## Logs a fatal error message to all registered handlers.
+  ##
+  ## A application-level fatal condition. FATAL usually means that the application
+  ## cannot go on and will exit (but this logging event will not do that for you).
   log(lvlFatal, args)
 
 proc addHandler*(handler: Logger) =
diff --git a/lib/pure/parseutils.nim b/lib/pure/parseutils.nim
index 3e25eba22..fb7d72182 100644
--- a/lib/pure/parseutils.nim
+++ b/lib/pure/parseutils.nim
@@ -173,6 +173,22 @@ proc parseUntil*(s: string, token: var string, until: char,
   result = i-start
   token = substr(s, start, i-1)
 
+proc parseUntil*(s: string, token: var string, until: string,
+                 start = 0): int {.inline.} =
+  ## 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.
+  var i = start
+  while i < s.len:
+    if s[i] == until[0]:
+      var u = 1
+      while i+u < s.len and u < until.len and s[i+u] == until[u]:
+        inc u
+      if u >= until.len: break
+    inc(i)
+  result = i-start
+  token = substr(s, start, i-1)
+
 proc parseWhile*(s: string, token: var string, validChars: set[char],
                  start = 0): int {.inline.} =
   ## parses a token and stores it in ``token``. Returns
@@ -240,7 +256,7 @@ proc rawParseUInt(s: string, b: var uint64, start = 0): int =
     res = 0'u64
     prev = 0'u64
     i = start
-  if s[i] == '+': inc(i) # Allow 
+  if s[i] == '+': inc(i) # Allow
   if s[i] in {'0'..'9'}:
     b = 0
     while s[i] in {'0'..'9'}:
@@ -255,8 +271,10 @@ proc rawParseUInt(s: string, b: var uint64, start = 0): int =
 
 proc parseBiggestUInt*(s: string, number: var uint64, start = 0): int {.
   rtl, extern: "npuParseBiggestUInt", noSideEffect.} =
-  ## parses an unsigned integer starting at `start` and stores the value into `number`.
-  ## Result is the number of processed chars or 0 if there is no integer or overflow detected.
+  ## parses an unsigned integer starting at `start` and stores the value
+  ## into `number`.
+  ## Result is the number of processed chars or 0 if there is no integer
+  ## or overflow detected.
   var res: uint64
   # use 'res' for exception safety (don't write to 'number' in case of an
   # overflow exception):
@@ -265,8 +283,10 @@ proc parseBiggestUInt*(s: string, number: var uint64, start = 0): int {.
 
 proc parseUInt*(s: string, number: var uint, start = 0): int {.
   rtl, extern: "npuParseUInt", noSideEffect.} =
-  ## parses an unsigned integer starting at `start` and stores the value into `number`.
-  ## Result is the number of processed chars or 0 if there is no integer or overflow detected.
+  ## parses an unsigned integer starting at `start` and stores the value
+  ## into `number`.
+  ## Result is the number of processed chars or 0 if there is no integer or
+  ## overflow detected.
   var res: uint64
   result = parseBiggestUInt(s, res, start)
   if (sizeof(uint) <= 4) and
diff --git a/lib/pure/strscans.nim b/lib/pure/strscans.nim
new file mode 100644
index 000000000..f695c3e2a
--- /dev/null
+++ b/lib/pure/strscans.nim
@@ -0,0 +1,521 @@
+#
+#
+#            Nim's Runtime Library
+#        (c) Copyright 2016 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+##[
+This module contains a `scanf`:idx: macro that can be used for extracting
+substrings from an input string. This is often easier than regular expressions.
+Some examples as an apetizer:
+
+.. code-block:: nim
+  # check if input string matches a triple of integers:
+  const input = "(1,2,4)"
+  var x, y, z: int
+  if scanf(input, "($i,$i,$i)", x, y, z):
+    echo "matches and x is ", x, " y is ", y, " z is ", z
+
+  # check if input string matches an ISO date followed by an identifier followed
+  # by whitespace and a floating point number:
+  var year, month, day: int
+  var identifier: string
+  var myfloat: float
+  if scanf(input, "$i-$i-$i $w$s$f", year, month, day, identifier, myfloat):
+    echo "yes, we have a match!"
+
+As can be seen from the examples, strings are matched verbatim except for
+substrings starting with ``$``. These constructions are available:
+
+=================   ========================================================
+``$i``              Matches an integer. This uses ``parseutils.parseInt``.
+``$f``              Matches a floating pointer number. Uses ``parseFloat``.
+``$w``              Matches an ASCII identifier: ``[A-Z-a-z_][A-Za-z_0-9]*``.
+``$s``              Skips optional whitespace.
+``$$``              Matches a single dollar sign.
+``$.``              Matches if the end of the input string has been reached.
+``$*``              Matches until the token following the ``$*`` was found.
+                    The match is allowed to be of 0 length.
+``$+``              Matches until the token following the ``$+`` was found.
+                    The match must consist of at least one char.
+``${foo}``          User defined matcher. Uses the proc ``foo`` to perform
+                    the match. See below for more details.
+``$[foo]``          Call user defined proc ``foo`` to **skip** some optional
+                    parts in the input string. See below for more details.
+=================   ========================================================
+
+Even though ``$*`` and ``$+`` look similar to the regular expressions ``.*``
+and ``.+`` they work quite differently, there is no non-deterministic
+state machine involved and the matches are non-greedy. ``[$*]``
+matches ``[xyz]`` via ``parseutils.parseUntil``.
+
+Furthermore no backtracking is performed, if parsing fails after a value
+has already been bound to a matched subexpression this value is not restored
+to its original value. This rarely causes problems in practice and if it does
+for you, it's easy enough to bind to a temporary variable first.
+
+
+Startswith vs full match
+========================
+
+``scanf`` returns true if the input string **starts with** the specified
+pattern. If instead it should only return true if theres is also nothing
+left in the input, append ``$.`` to your pattern.
+
+
+User definable matchers
+=======================
+
+One very nice advantage over regular expressions is that ``scanf`` is
+extensible with ordinary Nim procs. The proc is either enclosed in ``${}``
+or in ``$[]``. ``${}`` matches and binds the result
+to a variable (that was passed to the ``scanf`` macro) while ``$[]`` merely
+optional tokens.
+
+
+In this example, we define a helper proc ``skipSep`` that skips some separators
+which we then use in our scanf pattern to help us in the matching process:
+
+.. code-block:: nim
+
+  proc someSep(input: string; start: int; seps: set[char] = {':','-','.'}): int =
+    # Note: The parameters and return value must match to what ``scanf`` requires
+    result = 0
+    while input[start+result] in seps: inc result
+
+  if scanf(input, "$w${someSep}$w", key, value):
+    ...
+
+It also possible to pass arguments to a user definable matcher:
+
+.. code-block:: nim
+
+  proc ndigits(input: string; start: int; intVal: var int; n: int): int =
+    # matches exactly ``n`` digits. Matchers need to return 0 if nothing
+    # matched or otherwise the number of processed chars.
+    var x = 0
+    var i = 0
+    while i < n and i+start < input.len and input[i+start] in {'0'..'9'}:
+      x = x * 10 + input[i+start].ord - '0'.ord
+      inc i
+    # only overwrite if we had a match
+    if i == n:
+      result = n
+      intVal = x
+
+  # match an ISO date extracting year, month, day at the same time.
+  # Also ensure the input ends after the ISO date:
+  var year, month, day: int
+  if scanf("2013-01-03", "${ndigits(4)}-${ndigits(2)}-${ndigits(2)}$.", year, month, day):
+    ...
+
+]##
+
+
+import macros, parseutils
+
+proc conditionsToIfChain(n, idx, res: NimNode; start: int): NimNode =
+  assert n.kind == nnkStmtList
+  if start >= n.len: return newAssignment(res, newLit true)
+  var ifs: NimNode = nil
+  if n[start+1].kind == nnkEmpty:
+    ifs = conditionsToIfChain(n, idx, res, start+3)
+  else:
+    ifs = newIfStmt((n[start+1],
+                    newTree(nnkStmtList, newCall(bindSym"inc", idx, n[start+2]),
+                                     conditionsToIfChain(n, idx, res, start+3))))
+  result = newTree(nnkStmtList, n[start], ifs)
+
+proc notZero(x: NimNode): NimNode = newCall(bindSym"!=", x, newLit 0)
+
+proc buildUserCall(x: string; args: varargs[NimNode]): NimNode =
+  let y = parseExpr(x)
+  result = newTree(nnkCall)
+  if y.kind in nnkCallKinds: result.add y[0]
+  else: result.add y
+  for a in args: result.add a
+  if y.kind in nnkCallKinds:
+    for i in 1..<y.len: result.add y[i]
+
+macro scanf*(input: string; pattern: static[string]; results: varargs[typed]): bool =
+  ## See top level documentation of his module of how ``scanf`` works.
+  template matchBind(parser) {.dirty.} =
+    var resLen = genSym(nskLet, "resLen")
+    conds.add newLetStmt(resLen, newCall(bindSym(parser), input, results[i], idx))
+    conds.add resLen.notZero
+    conds.add resLen
+
+  var i = 0
+  var p = 0
+  var idx = genSym(nskVar, "idx")
+  var res = genSym(nskVar, "res")
+  result = newTree(nnkStmtListExpr, newVarStmt(idx, newLit 0), newVarStmt(res, newLit false))
+  var conds = newTree(nnkStmtList)
+  var fullMatch = false
+  while p < pattern.len:
+    if pattern[p] == '$':
+      inc p
+      case pattern[p]
+      of '$':
+        var resLen = genSym(nskLet, "resLen")
+        conds.add newLetStmt(resLen, newCall(bindSym"skip", input, newLit($pattern[p]), idx))
+        conds.add resLen.notZero
+        conds.add resLen
+      of 'w':
+        if i < results.len or getType(results[i]).typeKind != ntyString:
+          matchBind "parseIdent"
+        else:
+          error("no string var given for $w")
+        inc i
+      of 'i':
+        if i < results.len or getType(results[i]).typeKind != ntyInt:
+          matchBind "parseInt"
+        else:
+          error("no int var given for $d")
+        inc i
+      of 'f':
+        if i < results.len or getType(results[i]).typeKind != ntyFloat:
+          matchBind "parseFloat"
+        else:
+          error("no float var given for $f")
+        inc i
+      of 's':
+        conds.add newCall(bindSym"inc", idx, newCall(bindSym"skipWhitespace", input, idx))
+        conds.add newEmptyNode()
+        conds.add newEmptyNode()
+      of '.':
+        if p == pattern.len-1:
+          fullMatch = true
+        else:
+          error("invalid format string")
+      of '*', '+':
+        if i < results.len or getType(results[i]).typeKind != ntyString:
+          var min = ord(pattern[p] == '+')
+          var q=p+1
+          var token = ""
+          while q < pattern.len and pattern[q] != '$':
+            token.add pattern[q]
+            inc q
+          var resLen = genSym(nskLet, "resLen")
+          conds.add newLetStmt(resLen, newCall(bindSym"parseUntil", input, results[i], newLit(token), idx))
+          conds.add newCall(bindSym"!=", resLen, newLit min)
+          conds.add resLen
+        else:
+          error("no string var given for $" & pattern[p])
+        inc i
+      of '{':
+        inc p
+        var nesting = 0
+        let start = p
+        while true:
+          case pattern[p]
+          of '{': inc nesting
+          of '}':
+            if nesting == 0: break
+            dec nesting
+          of '\0': error("expected closing '}'")
+          else: discard
+          inc p
+        let expr = pattern.substr(start, p-1)
+        if i < results.len:
+          var resLen = genSym(nskLet, "resLen")
+          conds.add newLetStmt(resLen, buildUserCall(expr, input, results[i], idx))
+          conds.add newCall(bindSym"!=", resLen, newLit 0)
+          conds.add resLen
+        else:
+          error("no var given for $" & expr)
+        inc i
+      of '[':
+        inc p
+        var nesting = 0
+        let start = p
+        while true:
+          case pattern[p]
+          of '[': inc nesting
+          of ']':
+            if nesting == 0: break
+            dec nesting
+          of '\0': error("expected closing ']'")
+          else: discard
+          inc p
+        let expr = pattern.substr(start, p-1)
+        conds.add newCall(bindSym"inc", idx, buildUserCall(expr, input, idx))
+        conds.add newEmptyNode()
+        conds.add newEmptyNode()
+      else: error("invalid format string")
+      inc p
+    else:
+      var token = ""
+      while p < pattern.len and pattern[p] != '$':
+        token.add pattern[p]
+        inc p
+      var resLen = genSym(nskLet, "resLen")
+      conds.add newLetStmt(resLen, newCall(bindSym"skip", input, newLit(token), idx))
+      conds.add resLen.notZero
+      conds.add resLen
+  result.add conditionsToIfChain(conds, idx, res, 0)
+  if fullMatch:
+    result.add newCall(bindSym">=", idx, newCall(bindSym"len", input))
+  else:
+    result.add res
+
+template atom*(input: string; idx: int; c: char): bool =
+  ## Used in scanp for the matching of atoms (usually chars).
+  input[idx] == c
+
+template atom*(input: string; idx: int; s: set[char]): bool =
+  input[idx] in s
+
+#template prepare*(input: string): int = 0
+template success*(x: int): bool = x != 0
+
+template nxt*(input: string; idx, step: int = 1) = inc(idx, step)
+
+macro scanp*(input, idx: typed; pattern: varargs[untyped]): bool =
+  ## See top level documentation of his module of how ``scanp`` works.
+  type StmtTriple = tuple[init, cond, action: NimNode]
+
+  template interf(x): untyped = bindSym(x, brForceOpen)
+
+  proc toIfChain(n: seq[StmtTriple]; idx, res: NimNode; start: int): NimNode =
+    if start >= n.len: return newAssignment(res, newLit true)
+    var ifs: NimNode = nil
+    if n[start].cond.kind == nnkEmpty:
+      ifs = toIfChain(n, idx, res, start+1)
+    else:
+      ifs = newIfStmt((n[start].cond,
+                      newTree(nnkStmtList, n[start].action,
+                              toIfChain(n, idx, res, start+1))))
+    result = newTree(nnkStmtList, n[start].init, ifs)
+
+  proc attach(x, attached: NimNode): NimNode =
+    if attached == nil: x
+    else: newStmtList(attached, x)
+
+  proc placeholder(n, x, j: NimNode): NimNode =
+    if n.kind == nnkPrefix and n[0].eqIdent("$"):
+      let n1 = n[1]
+      if n1.eqIdent"_" or n1.eqIdent"current":
+        result = newTree(nnkBracketExpr, x, j)
+      elif n1.eqIdent"input":
+        result = x
+      elif n1.eqIdent"i" or n1.eqIdent"index":
+        result = j
+      else:
+        error("unknown pattern " & repr(n))
+    else:
+      result = copyNimNode(n)
+      for i in 0 ..< n.len:
+        result.add placeholder(n[i], x, j)
+
+  proc atm(it, input, idx, attached: NimNode): StmtTriple =
+    template `!!`(x): untyped = attach(x, attached)
+    case it.kind
+    of nnkIdent:
+      var resLen = genSym(nskLet, "resLen")
+      result = (newLetStmt(resLen, newCall(it, input, idx)),
+                newCall(interf"success", resLen),
+                !!newCall(interf"nxt", input, idx, resLen))
+    of nnkCallKinds:
+      # *{'A'..'Z'} !! s.add(!_)
+      template buildWhile(init, cond, action): untyped =
+        while true:
+          init
+          if not cond: break
+          action
+
+      # (x) a  # bind action a to (x)
+      if it[0].kind == nnkPar and it.len == 2:
+        result = atm(it[0], input, idx, placeholder(it[1], input, idx))
+      elif it.kind == nnkInfix and it[0].eqIdent"->":
+        # bind matching to some action:
+        result = atm(it[1], input, idx, placeholder(it[2], input, idx))
+      elif it.kind == nnkInfix and it[0].eqIdent"as":
+        let cond = if it[1].kind in nnkCallKinds: placeholder(it[1], input, idx)
+                   else: newCall(it[1], input, idx)
+        result = (newLetStmt(it[2], cond),
+                  newCall(interf"success", it[2]),
+                  !!newCall(interf"nxt", input, idx, it[2]))
+      elif it.kind == nnkPrefix and it[0].eqIdent"*":
+        let (init, cond, action) = atm(it[1], input, idx, attached)
+        result = (getAst(buildWhile(init, cond, action)),
+                  newEmptyNode(), newEmptyNode())
+      elif it.kind == nnkPrefix and it[0].eqIdent"+":
+        # x+  is the same as  xx*
+        result = atm(newTree(nnkPar, it[1], newTree(nnkPrefix, ident"*", it[1])),
+                      input, idx, attached)
+      elif it.kind == nnkPrefix and it[0].eqIdent"?":
+        # optional.
+        let (init, cond, action) = atm(it[1], input, idx, attached)
+        if cond.kind == nnkEmpty:
+          error("'?' operator applied to a non-condition")
+        else:
+          result = (newTree(nnkStmtList, init, newIfStmt((cond, action))),
+                    newEmptyNode(), newEmptyNode())
+      elif it.kind == nnkPrefix and it[0].eqIdent"~":
+        # not operator
+        let (init, cond, action) = atm(it[1], input, idx, attached)
+        if cond.kind == nnkEmpty:
+          error("'~' operator applied to a non-condition")
+        else:
+          result = (init, newCall(bindSym"not", cond), action)
+      elif it.kind == nnkInfix and it[0].eqIdent"|":
+        let a = atm(it[1], input, idx, attached)
+        let b = atm(it[2], input, idx, attached)
+        if a.cond.kind == nnkEmpty or b.cond.kind == nnkEmpty:
+          error("'|' operator applied to a non-condition")
+        else:
+          result = (newStmtList(a.init,
+                newIfStmt((a.cond, a.action), (newTree(nnkStmtListExpr, b.init, b.cond), b.action))),
+              newEmptyNode(), newEmptyNode())
+      elif it.kind == nnkInfix and it[0].eqIdent"^*":
+        # a ^* b  is rewritten to:  (a *(b a))?
+        #exprList = expr ^+ comma
+        template tmp(a, b): untyped = ?(a, *(b, a))
+        result = atm(getAst(tmp(it[1], it[2])), input, idx, attached)
+
+      elif it.kind == nnkInfix and it[0].eqIdent"^+":
+        # a ^* b  is rewritten to:  (a +(b a))?
+        template tmp(a, b): untyped = (a, *(b, a))
+        result = atm(getAst(tmp(it[1], it[2])), input, idx, attached)
+      elif it.kind == nnkCommand and it.len == 2 and it[0].eqIdent"pred":
+        # enforce that the wrapped call is interpreted as a predicate, not a non-terminal:
+        result = (newEmptyNode(), placeholder(it[1], input, idx), newEmptyNode())
+      else:
+        var resLen = genSym(nskLet, "resLen")
+        result = (newLetStmt(resLen, placeholder(it, input, idx)),
+                  newCall(interf"success", resLen), !!newCall(interf"nxt", input, idx, resLen))
+    of nnkStrLit..nnkTripleStrLit:
+      var resLen = genSym(nskLet, "resLen")
+      result = (newLetStmt(resLen, newCall(interf"skip", input, it, idx)),
+                newCall(interf"success", resLen), !!newCall(interf"nxt", input, idx, resLen))
+    of nnkCurly, nnkAccQuoted, nnkCharLit:
+      result = (newEmptyNode(), newCall(interf"atom", input, idx, it), !!newCall(interf"nxt", input, idx))
+    of nnkCurlyExpr:
+      if it.len == 3 and it[1].kind == nnkIntLit and it[2].kind == nnkIntLit:
+        var h = newTree(nnkPar, it[0])
+        for count in 2..it[1].intVal: h.add(it[0])
+        for count in it[1].intVal .. it[2].intVal-1: h.add(newTree(nnkPrefix, ident"?", it[0]))
+        result = atm(h, input, idx, attached)
+      elif it.len == 2 and it[1].kind == nnkIntLit:
+        var h = newTree(nnkPar, it[0])
+        for count in 2..it[1].intVal: h.add(it[0])
+        result = atm(h, input, idx, attached)
+      else:
+        error("invalid pattern")
+    of nnkPar:
+      if it.len == 1:
+        result = atm(it[0], input, idx, attached)
+      else:
+        # concatenation:
+        var conds: seq[StmtTriple] = @[]
+        for x in it: conds.add atm(x, input, idx, attached)
+        var res = genSym(nskVar, "res")
+        result = (newStmtList(newVarStmt(res, newLit false),
+            toIfChain(conds, idx, res, 0)), res, newEmptyNode())
+    else:
+      error("invalid pattern")
+
+  #var idx = genSym(nskVar, "idx")
+  var res = genSym(nskVar, "res")
+  result = newTree(nnkStmtListExpr, #newVarStmt(idx, newCall(interf"prepare", input)),
+                                    newVarStmt(res, newLit false))
+  var conds: seq[StmtTriple] = @[]
+  for it in pattern:
+    conds.add atm(it, input, idx, nil)
+  result.add toIfChain(conds, idx, res, 0)
+  result.add res
+  when defined(debugScanp):
+    echo repr result
+
+
+when isMainModule:
+  proc twoDigits(input: string; x: var int; start: int): int =
+    if input[start] == '0' and input[start+1] == '0':
+      result = 2
+      x = 13
+    else:
+      result = 0
+
+  proc someSep(input: string; start: int; seps: set[char] = {';',',','-','.'}): int =
+    result = 0
+    while input[start+result] in seps: inc result
+
+  proc demangle(s: string; res: var string; start: int): int =
+    while s[result+start] in {'_', '@'}: inc result
+    res = ""
+    while result+start < s.len and s[result+start] > ' ' and s[result+start] != '_':
+      res.add s[result+start]
+      inc result
+    while result+start < s.len and s[result+start] > ' ':
+      inc result
+
+  proc parseGDB(resp: string): seq[string] =
+    const
+      digits = {'0'..'9'}
+      hexdigits = digits + {'a'..'f', 'A'..'F'}
+      whites = {' ', '\t', '\C', '\L'}
+    result = @[]
+    var idx = 0
+    while true:
+      var prc = ""
+      var info = ""
+      if scanp(resp, idx, *`whites`, '#', *`digits`, +`whites`, ?("0x", *`hexdigits`, " in "),
+               demangle($input, prc, $index), *`whites`, '(', * ~ ')', ')',
+                *`whites`, "at ", +(~{'\C', '\L', '\0'} -> info.add($_)) ):
+        result.add prc & " " & info
+      else:
+        break
+
+  var key, val: string
+  var intval: int
+  var floatval: float
+  doAssert scanf("abc:: xyz 89  33.25", "$w$s::$s$w$s$i  $f", key, val, intval, floatVal)
+  doAssert key == "abc"
+  doAssert val == "xyz"
+  doAssert intval == 89
+  doAssert floatVal == 33.25
+
+  let xx = scanf("$abc", "$$$i", intval)
+  doAssert xx == false
+
+
+  let xx2 = scanf("$1234", "$$$i", intval)
+  doAssert xx2
+
+  let yy = scanf(";.--Breakpoint00 [output]", "$[someSep]Breakpoint${twoDigits}$[someSep({';','.','-'})] [$+]$.", intVal, key)
+  doAssert yy
+  doAssert key == "output"
+  doAssert intVal == 13
+
+  var ident = ""
+  var idx = 0
+  let zz = scanp("foobar x x  x   xWZ", idx, +{'a'..'z'} -> add(ident, $_), *(*{' ', '\t'}, "x"), ~'U', "Z")
+  doAssert zz
+  doAssert ident == "foobar"
+
+  const digits = {'0'..'9'}
+  var year = 0
+  var idx2 = 0
+  if scanp("201655-8-9", idx2, `digits`{4,6} -> (year = year * 10 + ord($_) - ord('0')), "-8", "-9"):
+    doAssert year == 201655
+
+  const gdbOut = """
+      #0  @foo_96013_1208911747@8 (x0=...)
+          at c:/users/anwender/projects/nim/temp.nim:11
+      #1  0x00417754 in tempInit000 () at c:/users/anwender/projects/nim/temp.nim:13
+      #2  0x0041768d in NimMainInner ()
+          at c:/users/anwender/projects/nim/lib/system.nim:2605
+      #3  0x004176b1 in NimMain ()
+          at c:/users/anwender/projects/nim/lib/system.nim:2613
+      #4  0x004176db in main (argc=1, args=0x712cc8, env=0x711ca8)
+          at c:/users/anwender/projects/nim/lib/system.nim:2620"""
+  const result = @["foo c:/users/anwender/projects/nim/temp.nim:11",
+          "tempInit000 c:/users/anwender/projects/nim/temp.nim:13",
+          "NimMainInner c:/users/anwender/projects/nim/lib/system.nim:2605",
+          "NimMain c:/users/anwender/projects/nim/lib/system.nim:2613",
+          "main c:/users/anwender/projects/nim/lib/system.nim:2620"]
+  doAssert parseGDB(gdbOut) == result
diff --git a/lib/pure/strutils.nim b/lib/pure/strutils.nim
index a5a4ee509..c3d6d75bd 100644
--- a/lib/pure/strutils.nim
+++ b/lib/pure/strutils.nim
@@ -669,7 +669,7 @@ proc repeat*(s: string, n: Natural): string {.noSideEffect,
   result = newStringOfCap(n * s.len)
   for i in 1..n: result.add(s)
 
-template spaces*(n: Natural): string =  repeat(' ',n)
+template spaces*(n: Natural): string = repeat(' ', n)
   ## Returns a String with `n` space characters. You can use this proc
   ## to left align strings. Example:
   ##