version0.7.10

lib/hashes.nim

@@ -1,97 +0,0 @@
-#
-#
-#            Nimrod's Runtime Library
-#        (c) Copyright 2008 Andreas Rumpf
-#
-#    See the file "copying.txt", included in this
-#    distribution, for details about the copyright.
-#
-
-## This module implements efficient computations of hash values for diverse
-## Nimrod types.
-
-import 
-  strutils
-
-type 
-  THash* = int ## a hash value; hash tables using these values should 
-               ## always have a size of a power of two and can use the ``and``
-               ## operator instead of ``mod`` for truncation of the hash value.
-
-proc concHash(h: THash, val: int): THash {.inline.} = 
-  result = h +% val
-  result = result +% result shl 10
-  result = result xor (result shr 6)
-
-proc finishHash(h: THash): THash {.inline.} = 
-  result = h +% h shl 3
-  result = result xor (result shr 11)
-  result = result +% result shl 15
-
-proc hashData*(Data: Pointer, Size: int): THash = 
-  ## hashes an array of bytes of size `size`
-  var 
-    h: THash
-    p: cstring
-    i, s: int
-  h = 0
-  p = cast[cstring](Data)
-  i = 0
-  s = size
-  while s > 0: 
-    h = concHash(h, ord(p[i]))
-    Inc(i)
-    Dec(s)
-  result = finishHash(h)
-
-proc hash*(x: Pointer): THash {.inline.} = 
-  ## efficient hashing of pointers
-  result = (cast[THash](x)) shr 3 # skip the alignment
-  
-proc hash*(x: int): THash {.inline.} = 
-  ## efficient hashing of integers
-  result = x
-
-proc hash*(x: int64): THash {.inline.} = 
-  ## efficient hashing of integers
-  result = toU32(x)
-
-proc hash*(x: char): THash {.inline.} = 
-  ## efficient hashing of characters
-  result = ord(x)
-
-proc hash*(x: string): THash = 
-  ## efficient hashing of strings
-  var h: THash
-  h = 0
-  for i in 0..x.len-1: 
-    h = concHash(h, ord(x[i]))
-  result = finishHash(h)
-  
-proc hashIgnoreStyle*(x: string): THash = 
-  ## efficient hashing of strings; style is ignored
-  var 
-    h: THash
-    c: Char
-  h = 0
-  for i in 0..x.len-1: 
-    c = x[i]
-    if c == '_': 
-      continue                # skip _
-    if c in {'A'..'Z'}: 
-      c = chr(ord(c) + (ord('a') - ord('A'))) # toLower()
-    h = concHash(h, ord(c))
-  result = finishHash(h)
-
-proc hashIgnoreCase*(x: string): THash = 
-  ## efficient hashing of strings; case is ignored
-  var 
-    h: THash
-    c: Char
-  h = 0
-  for i in 0..x.len-1: 
-    c = x[i]
-    if c in {'A'..'Z'}: 
-      c = chr(ord(c) + (ord('a') - ord('A'))) # toLower()
-    h = concHash(h, ord(c))
-  result = finishHash(h)