1 files changed, 146 insertions, 0 deletions
diff --git a/re2/make_unicode_casefold.py b/re2/make_unicode_casefold.py
new file mode 100755
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+++ b/re2/make_unicode_casefold.py
@@ -0,0 +1,146 @@
+#!/usr/bin/python
+# coding=utf-8
+#
+# Copyright 2008 The RE2 Authors.  All Rights Reserved.
+# Use of this source code is governed by a BSD-style
+# license that can be found in the LICENSE file.
+
+# See unicode_casefold.h for description of case folding tables.
+
+"""Generate C++ table for Unicode case folding."""
+
+import unicode, sys
+
+_header = """
+// GENERATED BY make_unicode_casefold.py; DO NOT EDIT.
+// make_unicode_casefold.py >unicode_casefold.cc
+
+#include "re2/unicode_casefold.h"
+
+namespace re2 {
+
+"""
+
+_trailer = """
+
+} // namespace re2
+
+"""
+
+def _Delta(a, b):
+  """Compute the delta for b - a.  Even/odd and odd/even
+     are handled specially, as described above."""
+  if a+1 == b:
+    if a%2 == 0:
+      return 'EvenOdd'
+    else:
+      return 'OddEven'
+  if a == b+1:
+    if a%2 == 0:
+      return 'OddEven'
+    else:
+      return 'EvenOdd'
+  return b - a
+
+def _AddDelta(a, delta):
+  """Return a + delta, handling EvenOdd and OddEven specially."""
+  if type(delta) == int:
+    return a+delta
+  if delta == 'EvenOdd':
+    if a%2 == 0:
+      return a+1
+    else:
+      return a-1
+  if delta == 'OddEven':
+    if a%2 == 1:
+      return a+1
+    else:
+      return a-1
+  print >>sys.stderr, "Bad Delta: ", delta
+  raise "Bad Delta"
+
+def _MakeRanges(pairs):
+  """Turn a list like [(65,97), (66, 98), ..., (90,122)]
+     into [(65, 90, +32)]."""
+  ranges = []
+  last = -100
+
+  def evenodd(last, a, b, r):
+    if a != last+1 or b != _AddDelta(a, r[2]):
+      return False
+    r[1] = a
+    return True
+
+  def evenoddpair(last, a, b, r):
+    if a != last+2:
+      return False
+    delta = r[2]
+    d = delta
+    if type(delta) is not str:
+      return False
+    if delta.endswith('Skip'):
+      d = delta[:-4]
+    else:
+      delta = d + 'Skip'
+    if b != _AddDelta(a, d):
+      return False
+    r[1] = a
+    r[2] = delta
+    return True
+
+  for a, b in pairs:
+    if ranges and evenodd(last, a, b, ranges[-1]):
+      pass
+    elif ranges and evenoddpair(last, a, b, ranges[-1]):
+      pass
+    else:
+      ranges.append([a, a, _Delta(a, b)])
+    last = a
+  return ranges
+
+# The maximum size of a case-folding group.
+# Case folding is implemented in parse.cc by a recursive process
+# with a recursion depth equal to the size of the largest
+# case-folding group, so it is important that this bound be small.
+# The current tables have no group bigger than 4.
+# If there are ever groups bigger than 10 or so, it will be
+# time to rework the code in parse.cc.
+MaxCasefoldGroup = 4
+
+def main():
+  lowergroups, casegroups = unicode.CaseGroups()
+  foldpairs = []
+  seen = {}
+  for c in casegroups:
+    if len(c) > MaxCasefoldGroup:
+      raise unicode.Error("casefold group too long: %s" % (c,))
+    for i in range(len(c)):
+      if c[i-1] in seen:
+        raise unicode.Error("bad casegroups %d -> %d" % (c[i-1], c[i]))
+      seen[c[i-1]] = True
+      foldpairs.append([c[i-1], c[i]])
+
+  lowerpairs = []
+  for lower, group in lowergroups.iteritems():
+    for g in group:
+      if g != lower:
+        lowerpairs.append([g, lower])
+
+  def printpairs(name, foldpairs):
+    foldpairs.sort()
+    foldranges = _MakeRanges(foldpairs)
+    print "// %d groups, %d pairs, %d ranges" % (len(casegroups), len(foldpairs), len(foldranges))
+    print "CaseFold unicode_%s[] = {" % (name,)
+    for lo, hi, delta in foldranges:
+      print "\t{ %d, %d, %s }," % (lo, hi, delta)
+    print "};"
+    print "int num_unicode_%s = %d;" % (name, len(foldranges),)
+    print ""
+
+  print _header
+  printpairs("casefold", foldpairs)
+  printpairs("tolower", lowerpairs)
+  print _trailer
+
+if __name__ == '__main__':
+  main()