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-rw-r--r--compiler/ropes.nim372
1 files changed, 180 insertions, 192 deletions
diff --git a/compiler/ropes.nim b/compiler/ropes.nim
index ad6801d18..edac8e9d0 100644
--- a/compiler/ropes.nim
+++ b/compiler/ropes.nim
@@ -55,81 +55,63 @@
 #  share leaves across different rope trees.
 #  To cache them they are inserted in a `cache` array.
 
-import 
-  strutils, platform, hashes, crc, options
+import
+  platform, hashes
 
 type
-  TFormatStr* = string # later we may change it to CString for better
-                       # performance of the code generator (assignments 
+  FormatStr* = string  # later we may change it to CString for better
+                       # performance of the code generator (assignments
                        # copy the format strings
                        # though it is not necessary)
-  PRope* = ref TRope
-  TRope*{.acyclic.} = object of RootObj # the empty rope is represented 
-                                        # by nil to safe space
-    left*, right*: PRope
+  Rope* = ref RopeObj
+  RopeObj*{.acyclic.} = object of RootObj # the empty rope is represented
+                                          # by nil to safe space
+    left*, right*: Rope
     length*: int
     data*: string             # != nil if a leaf
-  
-  TRopeSeq* = seq[PRope]
 
-  TRopesError* = enum
+  RopeSeq* = seq[Rope]
+
+  RopesError* = enum
     rCannotOpenFile
     rInvalidFormatStr
-    rTokenTooLong
-
-proc con*(a, b: PRope): PRope
-proc con*(a: PRope, b: string): PRope
-proc con*(a: string, b: PRope): PRope
-proc con*(a: varargs[PRope]): PRope
-proc app*(a: var PRope, b: PRope)
-proc app*(a: var PRope, b: string)
-proc prepend*(a: var PRope, b: PRope)
-proc toRope*(s: string): PRope
-proc toRope*(i: BiggestInt): PRope
-proc ropeLen*(a: PRope): int
-proc writeRopeIfNotEqual*(r: PRope, filename: string): bool
-proc ropeToStr*(p: PRope): string
-proc ropef*(frmt: TFormatStr, args: varargs[PRope]): PRope
-proc appf*(c: var PRope, frmt: TFormatStr, args: varargs[PRope])
-proc ropeEqualsFile*(r: PRope, f: string): bool
-  # returns true if the rope r is the same as the contents of file f
-proc ropeInvariant*(r: PRope): bool
-  # exported for debugging
+
 # implementation
 
-var errorHandler*: proc(err: TRopesError, msg: string, useWarning = false)
+var errorHandler*: proc(err: RopesError, msg: string, useWarning = false)
   # avoid dependency on msgs.nim
-  
-proc ropeLen(a: PRope): int = 
+
+proc len*(a: Rope): int =
+  ## the rope's length
   if a == nil: result = 0
   else: result = a.length
-  
-proc newRope*(data: string = nil): PRope = 
+
+proc newRope(data: string = nil): Rope =
   new(result)
-  if data != nil: 
+  if data != nil:
     result.length = len(data)
     result.data = data
 
-proc newMutableRope*(capacity = 30): PRope =
+proc newMutableRope*(capacity = 30): Rope =
   ## creates a new rope that supports direct modifications of the rope's
   ## 'data' and 'length' fields.
   new(result)
   result.data = newStringOfCap(capacity)
 
-proc freezeMutableRope*(r: PRope) {.inline.} =
+proc freezeMutableRope*(r: Rope) {.inline.} =
   r.length = r.data.len
 
-var 
-  cache: array[0..2048*2 -1, PRope]
+var
+  cache: array[0..2048*2 - 1, Rope]
 
 proc resetRopeCache* =
   for i in low(cache)..high(cache):
     cache[i] = nil
 
-proc ropeInvariant(r: PRope): bool = 
-  if r == nil: 
+proc ropeInvariant(r: Rope): bool =
+  if r == nil:
     result = true
-  else: 
+  else:
     result = true #
                   #    if r.data <> snil then
                   #      result := true
@@ -137,13 +119,13 @@ proc ropeInvariant(r: PRope): bool =
                   #      result := (r.left <> nil) and (r.right <> nil);
                   #      if result then result := ropeInvariant(r.left);
                   #      if result then result := ropeInvariant(r.right);
-                  #    end 
+                  #    end
 
 var gCacheTries* = 0
 var gCacheMisses* = 0
 var gCacheIntTries* = 0
 
-proc insertInCache(s: string): PRope = 
+proc insertInCache(s: string): Rope =
   inc gCacheTries
   var h = hash(s) and high(cache)
   result = cache[h]
@@ -151,83 +133,78 @@ proc insertInCache(s: string): PRope =
     inc gCacheMisses
     result = newRope(s)
     cache[h] = result
-  
-proc toRope(s: string): PRope =
+
+proc rope*(s: string): Rope =
+  ## Converts a string to a rope.
   if s.len == 0:
     result = nil
   else:
     result = insertInCache(s)
   assert(ropeInvariant(result))
 
-proc ropeSeqInsert(rs: var TRopeSeq, r: PRope, at: Natural) = 
-  var length = len(rs)
-  if at > length: 
-    setLen(rs, at + 1)
-  else: 
-    setLen(rs, length + 1)    # move old rope elements:
-  for i in countdown(length, at + 1): 
-    rs[i] = rs[i - 1] # this is correct, I used pen and paper to validate it
-  rs[at] = r
-
-proc newRecRopeToStr(result: var string, resultLen: var int, r: PRope) = 
-  var stack = @[r]
-  while len(stack) > 0: 
-    var it = pop(stack)
-    while it.data == nil: 
-      add(stack, it.right)
-      it = it.left
-    assert(it.data != nil)
-    copyMem(addr(result[resultLen]), addr(it.data[0]), it.length)
-    inc(resultLen, it.length)
-    assert(resultLen <= len(result))
-
-proc ropeToStr(p: PRope): string = 
-  if p == nil: 
-    result = ""
-  else: 
-    result = newString(p.length)
-    var resultLen = 0
-    newRecRopeToStr(result, resultLen, p)
-
-proc con(a, b: PRope): PRope = 
-  if a == nil: result = b
-  elif b == nil: result = a
+proc rope*(i: BiggestInt): Rope =
+  ## Converts an int to a rope.
+  inc gCacheIntTries
+  result = rope($i)
+
+proc rope*(f: BiggestFloat): Rope =
+  ## Converts a float to a rope.
+  result = rope($f)
+
+proc `&`*(a, b: Rope): Rope =
+  if a == nil:
+    result = b
+  elif b == nil:
+    result = a
   else:
     result = newRope()
     result.length = a.length + b.length
     result.left = a
     result.right = b
 
-proc con(a: PRope, b: string): PRope = result = con(a, toRope(b))
-proc con(a: string, b: PRope): PRope = result = con(toRope(a), b)
-
-proc con(a: varargs[PRope]): PRope = 
-  for i in countup(0, high(a)): result = con(result, a[i])
-
-proc ropeConcat*(a: varargs[PRope]): PRope =
-  # not overloaded version of concat to speed-up `rfmt` a little bit
-  for i in countup(0, high(a)): result = con(result, a[i])
-
-proc toRope(i: BiggestInt): PRope =
-  inc gCacheIntTries
-  result = toRope($i)
-
-proc app(a: var PRope, b: PRope) = a = con(a, b)
-proc app(a: var PRope, b: string) = a = con(a, b)
-proc prepend(a: var PRope, b: PRope) = a = con(b, a)
-
-proc writeRope*(f: File, c: PRope) = 
-  var stack = @[c]
-  while len(stack) > 0: 
-    var it = pop(stack)
-    while it.data == nil: 
-      add(stack, it.right)
-      it = it.left
-      assert(it != nil)
-    assert(it.data != nil)
-    write(f, it.data)
-
-proc writeRope*(head: PRope, filename: string, useWarning = false) =
+proc `&`*(a: Rope, b: string): Rope =
+  ## the concatenation operator for ropes.
+  result = a & rope(b)
+
+proc `&`*(a: string, b: Rope): Rope =
+  ## the concatenation operator for ropes.
+  result = rope(a) & b
+
+proc `&`*(a: openArray[Rope]): Rope =
+  ## the concatenation operator for an openarray of ropes.
+  for i in countup(0, high(a)): result = result & a[i]
+
+proc add*(a: var Rope, b: Rope) =
+  ## adds `b` to the rope `a`.
+  a = a & b
+
+proc add*(a: var Rope, b: string) =
+  ## adds `b` to the rope `a`.
+  a = a & b
+
+iterator leaves*(r: Rope): string =
+  ## iterates over any leaf string in the rope `r`.
+  if r != nil:
+    var stack = @[r]
+    while stack.len > 0:
+      var it = stack.pop
+      while isNil(it.data):
+        stack.add(it.right)
+        it = it.left
+        assert(it != nil)
+      assert(it.data != nil)
+      yield it.data
+
+iterator items*(r: Rope): char =
+  ## iterates over any character in the rope `r`.
+  for s in leaves(r):
+    for c in items(s): yield c
+
+proc writeRope*(f: File, r: Rope) =
+  ## writes a rope to a file.
+  for s in leaves(r): write(f, s)
+
+proc writeRope*(head: Rope, filename: string, useWarning = false) =
   var f: File
   if open(f, filename, fmWrite):
     if head != nil: writeRope(f, head)
@@ -235,42 +212,69 @@ proc writeRope*(head: PRope, filename: string, useWarning = false) =
   else:
     errorHandler(rCannotOpenFile, filename, useWarning)
 
+proc `$`*(r: Rope): string =
+  ## converts a rope back to a string.
+  result = newString(r.len)
+  setLen(result, 0)
+  for s in leaves(r): add(result, s)
+
+proc ropeConcat*(a: varargs[Rope]): Rope =
+  # not overloaded version of concat to speed-up `rfmt` a little bit
+  for i in countup(0, high(a)): result = result & a[i]
+
+proc prepend*(a: var Rope, b: Rope) = a = b & a
+proc prepend*(a: var Rope, b: string) = a = b & a
+
 var
   rnl* = tnl.newRope
   softRnl* = tnl.newRope
 
-proc ropef(frmt: TFormatStr, args: varargs[PRope]): PRope = 
+proc `%`*(frmt: FormatStr, args: openArray[Rope]): Rope =
   var i = 0
   var length = len(frmt)
   result = nil
   var num = 0
-  while i <= length - 1: 
-    if frmt[i] == '$': 
+  while i < length:
+    if frmt[i] == '$':
       inc(i)                  # skip '$'
       case frmt[i]
-      of '$': 
-        app(result, "$")
+      of '$':
+        add(result, "$")
         inc(i)
-      of '#': 
+      of '#':
         inc(i)
-        app(result, args[num])
+        add(result, args[num])
         inc(num)
-      of '0'..'9': 
+      of '0'..'9':
         var j = 0
-        while true: 
-          j = (j * 10) + ord(frmt[i]) - ord('0')
+        while true:
+          j = j * 10 + ord(frmt[i]) - ord('0')
           inc(i)
-          if (i > length + 0 - 1) or not (frmt[i] in {'0'..'9'}): break 
+          if frmt[i] notin {'0'..'9'}: break
         num = j
         if j > high(args) + 1:
           errorHandler(rInvalidFormatStr, $(j))
         else:
-          app(result, args[j - 1])
+          add(result, args[j-1])
+      of '{':
+        inc(i)
+        var j = 0
+        while frmt[i] in {'0'..'9'}:
+          j = j * 10 + ord(frmt[i]) - ord('0')
+          inc(i)
+        num = j
+        if frmt[i] == '}': inc(i)
+        else: errorHandler(rInvalidFormatStr, $(frmt[i]))
+
+        if j > high(args) + 1:
+          errorHandler(rInvalidFormatStr, $(j))
+        else:
+          add(result, args[j-1])
       of 'n':
-        app(result, softRnl)
-        inc i
+        add(result, softRnl)
+        inc(i)
       of 'N':
-        app(result, rnl)
+        add(result, rnl)
         inc(i)
       else:
         errorHandler(rInvalidFormatStr, $(frmt[i]))
@@ -278,85 +282,69 @@ proc ropef(frmt: TFormatStr, args: varargs[PRope]): PRope =
     while i < length:
       if frmt[i] != '$': inc(i)
       else: break
-    if i - 1 >= start: 
-      app(result, substr(frmt, start, i - 1))
+    if i - 1 >= start:
+      add(result, substr(frmt, start, i - 1))
   assert(ropeInvariant(result))
 
+proc addf*(c: var Rope, frmt: FormatStr, args: openArray[Rope]) =
+  ## shortcut for ``add(c, frmt % args)``.
+  add(c, frmt % args)
+
 when true:
-  template `~`*(r: string): PRope = r.ropef
+  template `~`*(r: string): Rope = r % []
 else:
   {.push stack_trace: off, line_trace: off.}
-  proc `~`*(r: static[string]): PRope =
+  proc `~`*(r: static[string]): Rope =
     # this is the new optimized "to rope" operator
     # the mnemonic is that `~` looks a bit like a rope :)
-    var r {.global.} = r.ropef
+    var r {.global.} = r % []
     return r
   {.pop.}
 
-proc appf(c: var PRope, frmt: TFormatStr, args: varargs[PRope]) = 
-  app(c, ropef(frmt, args))
-
-const 
+const
   bufSize = 1024              # 1 KB is reasonable
 
-proc auxRopeEqualsFile(r: PRope, bin: var File, buf: pointer): bool = 
-  if r.data != nil:
-    if r.length > bufSize:
-      errorHandler(rTokenTooLong, r.data)
-      return
-    var readBytes = readBuffer(bin, buf, r.length)
-    result = readBytes == r.length and
-        equalMem(buf, addr(r.data[0]), r.length) # BUGFIX
-  else: 
-    result = auxRopeEqualsFile(r.left, bin, buf)
-    if result: result = auxRopeEqualsFile(r.right, bin, buf)
-  
-proc ropeEqualsFile(r: PRope, f: string): bool = 
-  var bin: File
-  result = open(bin, f)
-  if not result: 
-    return                    # not equal if file does not exist
-  var buf = alloc(bufSize)
-  result = auxRopeEqualsFile(r, bin, buf)
-  if result: 
-    result = readBuffer(bin, buf, bufSize) == 0 # really at the end of file?
-  dealloc(buf)
-  close(bin)
-
-proc crcFromRopeAux(r: PRope, startVal: TCrc32): TCrc32 = 
-  if r.data != nil: 
-    result = startVal
-    for i in countup(0, len(r.data) - 1): 
-      result = updateCrc32(r.data[i], result)
-  else: 
-    result = crcFromRopeAux(r.left, startVal)
-    result = crcFromRopeAux(r.right, result)
-
-proc newCrcFromRopeAux(r: PRope, startVal: TCrc32): TCrc32 = 
-  # XXX profiling shows this is actually expensive
-  var stack: TRopeSeq = @[r]
-  result = startVal
-  while len(stack) > 0: 
-    var it = pop(stack)
-    while it.data == nil: 
-      add(stack, it.right)
-      it = it.left
-    assert(it.data != nil)
-    var i = 0
-    var L = len(it.data)
-    while i < L: 
-      result = updateCrc32(it.data[i], result)
-      inc(i)
-
-proc crcFromRope(r: PRope): TCrc32 = 
-  result = newCrcFromRopeAux(r, InitCrc32)
-
-proc writeRopeIfNotEqual(r: PRope, filename: string): bool = 
+proc equalsFile*(r: Rope, f: File): bool =
+  ## returns true if the contents of the file `f` equal `r`.
+  var 
+    buf: array[bufSize, char]
+    bpos = buf.len
+    blen = buf.len
+
+  for s in leaves(r):
+    var spos = 0
+    let slen = s.len
+    while spos < slen:
+      if bpos == blen:
+        # Read more data
+        bpos = 0
+        blen = readBuffer(f, addr(buf[0]), buf.len)
+        if blen == 0:  # no more data in file
+          result = false
+          return
+      let n = min(blen - bpos, slen - spos)
+      # TODO There's gotta be a better way of comparing here...
+      if not equalMem(addr(buf[bpos]), cast[pointer](cast[int](cstring(s))+spos), n):
+        result = false
+        return
+      spos += n
+      bpos += n
+
+  result = readBuffer(f, addr(buf[0]), 1) == 0  # check that we've read all
+
+proc equalsFile*(r: Rope, filename: string): bool =
+  ## returns true if the contents of the file `f` equal `r`. If `f` does not
+  ## exist, false is returned.
+  var f: File
+  result = open(f, filename)
+  if result:
+    result = equalsFile(r, f)
+    close(f)
+
+proc writeRopeIfNotEqual*(r: Rope, filename: string): bool =
   # returns true if overwritten
-  var c: TCrc32
-  c = crcFromFile(filename)
-  if c != crcFromRope(r): 
+  if not equalsFile(r, filename):
     writeRope(r, filename)
     result = true
-  else: 
+  else:
     result = false