1 files changed, 59 insertions, 42 deletions

diff --git a/compiler/idents.nim b/compiler/idents.nim
index a50c5269c..34177e76d 100644
--- a/compiler/idents.nim
+++ b/compiler/idents.nim
@@ -1,6 +1,6 @@
 #
 #
-#           The Nimrod Compiler
+#           The Nim Compiler
 #        (c) Copyright 2012 Andreas Rumpf
 #
 #    See the file "copying.txt", included in this
@@ -11,23 +11,29 @@
 # An identifier is a shared immutable string that can be compared by its
 # id. This module is essential for the compiler's performance.
 
-import 
-  hashes, strutils
+import wordrecg
+import std/hashes
 
-type 
-  TIdObj* = object of TObject
-    id*: int # unique id; use this for comparisons and not the pointers
-  
-  PIdObj* = ref TIdObj
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
+type
   PIdent* = ref TIdent
-  TIdent*{.acyclic.} = object of TIdObj
+  TIdent*{.acyclic.} = object
+    id*: int # unique id; use this for comparisons and not the pointers
     s*: string
     next*: PIdent             # for hash-table chaining
-    h*: THash                 # hash value of s
-  
-var buckets*: array[0..4096 * 2 - 1, PIdent]
+    h*: Hash                 # hash value of s
+
+  IdentCache* = ref object
+    buckets: array[0..4096 * 2 - 1, PIdent]
+    wordCounter: int
+    idAnon*, idDelegator*, emptyIdent*: PIdent
 
-proc cmpIgnoreStyle(a, b: cstring, blen: int): int =
+proc resetIdentCache*() = discard
+
+proc cmpIgnoreStyle*(a, b: cstring, blen: int): int =
+  if a[0] != b[0]: return 1
   var i = 0
   var j = 0
   result = 1
@@ -40,12 +46,12 @@ proc cmpIgnoreStyle(a, b: cstring, blen: int): int =
     if aa >= 'A' and aa <= 'Z': aa = chr(ord(aa) + (ord('a') - ord('A')))
     if bb >= 'A' and bb <= 'Z': bb = chr(ord(bb) + (ord('a') - ord('A')))
     result = ord(aa) - ord(bb)
-    if (result != 0) or (aa == '\0'): break 
+    if (result != 0) or (aa == '\0'): break
     inc(i)
     inc(j)
   if result == 0:
     if a[i] != '\0': result = 1
-  
+
 proc cmpExact(a, b: cstring, blen: int): int =
   var i = 0
   var j = 0
@@ -54,27 +60,25 @@ proc cmpExact(a, b: cstring, blen: int): int =
     var aa = a[i]
     var bb = b[j]
     result = ord(aa) - ord(bb)
-    if (result != 0) or (aa == '\0'): break 
+    if (result != 0) or (aa == '\0'): break
     inc(i)
     inc(j)
-  if result == 0: 
+  if result == 0:
     if a[i] != '\0': result = 1
 
-var wordCounter = 1
-
-proc getIdent*(identifier: cstring, length: int, h: THash): PIdent =
-  var idx = h and high(buckets)
-  result = buckets[idx]
+proc getIdent*(ic: IdentCache; identifier: cstring, length: int, h: Hash): PIdent =
+  var idx = h and high(ic.buckets)
+  result = ic.buckets[idx]
   var last: PIdent = nil
   var id = 0
-  while result != nil: 
-    if cmpExact(cstring(result.s), identifier, length) == 0: 
-      if last != nil: 
+  while result != nil:
+    if cmpExact(cstring(result.s), identifier, length) == 0:
+      if last != nil:
         # make access to last looked up identifier faster:
         last.next = result.next
-        result.next = buckets[idx]
-        buckets[idx] = result
-      return 
+        result.next = ic.buckets[idx]
+        ic.buckets[idx] = result
+      return
     elif cmpIgnoreStyle(cstring(result.s), identifier, length) == 0:
       assert((id == 0) or (id == result.id))
       id = result.id
@@ -83,24 +87,37 @@ proc getIdent*(identifier: cstring, length: int, h: THash): PIdent =
   new(result)
   result.h = h
   result.s = newString(length)
-  for i in countup(0, length - 1): result.s[i] = identifier[i]
-  result.next = buckets[idx]
-  buckets[idx] = result
-  if id == 0: 
-    inc(wordCounter)
-    result.id = -wordCounter
-  else: 
+  for i in 0..<length: result.s[i] = identifier[i]
+  result.next = ic.buckets[idx]
+  ic.buckets[idx] = result
+  if id == 0:
+    inc(ic.wordCounter)
+    result.id = -ic.wordCounter
+  else:
     result.id = id
 
-proc getIdent*(identifier: string): PIdent = 
-  result = getIdent(cstring(identifier), len(identifier), 
+proc getIdent*(ic: IdentCache; identifier: string): PIdent =
+  result = getIdent(ic, cstring(identifier), identifier.len,
                     hashIgnoreStyle(identifier))
 
-proc getIdent*(identifier: string, h: THash): PIdent = 
-  result = getIdent(cstring(identifier), len(identifier), h)
+proc getIdent*(ic: IdentCache; identifier: string, h: Hash): PIdent =
+  result = getIdent(ic, cstring(identifier), identifier.len, h)
 
-proc IdentEq*(id: PIdent, name: string): bool = 
-  result = id.id == getIdent(name).id
+proc newIdentCache*(): IdentCache =
+  result = IdentCache()
+  result.idAnon = result.getIdent":anonymous"
+  result.wordCounter = 1
+  result.idDelegator = result.getIdent":delegator"
+  result.emptyIdent = result.getIdent("")
+  # initialize the keywords:
+  for s in succ(low(TSpecialWord))..high(TSpecialWord):
+    result.getIdent($s, hashIgnoreStyle($s)).id = ord(s)
 
-var idAnon* = getIdent":anonymous"
+proc whichKeyword*(id: PIdent): TSpecialWord =
+  if id.id < 0: result = wInvalid
+  else: result = TSpecialWord(id.id)
 
+proc hash*(x: PIdent): Hash {.inline.} = x.h
+proc `==`*(a, b: PIdent): bool {.inline.} =
+  if a.isNil or b.isNil: result = system.`==`(a, b)
+  else: result = a.id == b.id