Initial import

lib/sets.nim

@@ -0,0 +1,88 @@
+#
+#
+#            Nimrod's Runtime Library
+#        (c) Copyright 2006 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+# set handling
+
+type
+  TMyByte = int8
+  TNimSet = array [0..4*2048-1, TMyByte]
+
+# implementation:
+
+proc countBits(n: int32): int {.exportc: "countBits".}
+# We use a prototype here, not in "cntbits.nim", because that is included
+# in math.nim too. So when linking with math.nim it'd give a duplicated
+# symbol error which we avoid by renaming here.
+
+include cntbits
+
+proc unionSets(res: var TNimSet, a, b: TNimSet, len: int) {.
+    compilerproc, inline.} =
+  for i in countup(0, len-1): res[i] = toU8(ze(a[i]) or ze(b[i]))
+
+proc diffSets(res: var TNimSet, a, b: TNimSet, len: int) {.
+    compilerproc, inline.} =
+  for i in countup(0, len-1): res[i] = toU8(ze(a[i]) and not ze(b[i]))
+
+proc intersectSets(res: var TNimSet, a, b: TNimSet, len: int) {.
+    compilerproc, inline.} =
+  for i in countup(0, len-1): res[i] = toU8(ze(a[i]) and ze(b[i]))
+
+proc symdiffSets(res: var TNimSet, a, b: TNimSet, len: int) {.
+    compilerproc, inline.} =
+  for i in countup(0, len-1): res[i] = toU8(ze(a[i]) xor ze(b[i]))
+
+proc containsSets(a, b: TNimSet, len: int): bool {.compilerproc, inline.} =
+  # s1 <= s2 ?
+  for i in countup(0, len-1):
+    if (ze(a[i]) and not ze(b[i])) != 0: return false
+  return true
+
+proc containsSubsets(a, b: TNimSet, len: int): bool {.compilerproc, inline.} =
+  # s1 < s2 ?
+  result = false # assume they are equal
+  for i in countup(0, len-1):
+    if (ze(a[i]) and not ze(b[i])) != 0: return false
+    if ze(a[i]) != ze(b[i]): result = true # they are not equal
+
+proc equalSets(a, b: TNimSet, len: int): bool {.compilerproc, inline.} =
+  for i in countup(0, len-1):
+    if ze(a[i]) != ze(b[i]): return false
+  return true
+
+proc cardSet(s: TNimSet, len: int): int {.compilerproc, inline.} =
+  result = 0
+  for i in countup(0, len-1):
+    inc(result, countBits(ze(s[i])))
+
+const
+  WORD_SIZE = sizeof(TMyByte)*8
+
+proc inSet(s: TNimSet, elem: int): bool {.compilerproc, inline.} =
+  return (s[elem /% WORD_SIZE] and (1 shl (elem %% WORD_SIZE))) != 0
+
+proc inclSets(s: var TNimSet, e: int) {.compilerproc, inline.} =
+  s[e /% WORD_SIZE] = toU8(s[e /% WORD_SIZE] or (1 shl (e %% WORD_SIZE)))
+
+proc inclRange(s: var TNimSet, first, last: int) {.compilerproc.} =
+  # not very fast, but it is seldom used
+  for i in countup(first, last): inclSets(s, i)
+
+proc smallInclRange(s: var int, first, last: int) {.compilerproc.} =
+  # not very fast, but it is seldom used
+  for i in countup(first, last):
+    s = s or (1 shl (i %% sizeof(int)*8))
+
+proc exclSets(s: var TNimSet, e: int) {.compilerproc, inline.} =
+  s[e /% WORD_SIZE] = toU8(s[e /% WORD_SIZE] and
+    not (1 shl (e %% WORD_SIZE)))
+
+proc smallContainsSubsets(a, b: int): bool {.compilerProc, inline.} =
+  # not used by new code generator
+  return ((a and not b) != 0) and (a != b)