UnicodeExtendedGraphemeClusters.cpp.gyb

%# -*- mode: C++ -*-

%# Ignore the following admonition; it applies to the resulting .cpp file only
//// Automatically Generated From UnicodeExtendedGraphemeClusters.cpp.gyb.
//// Do Not Edit Directly!
//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//

%{

import re

# Grapheme_Cluster_Break property.  An array of tuples (startCodePoint,
# endCodePoint, value).
graphemeBreakProperty = []

with open(unicodeGraphemeBreakPropertyFile, 'rb') as f:
    for line in f:
        # Strip comments.
        line = re.sub('#.*', '', line)

        # Single code point?
        m = re.match('([0-9A-F]+) +; +([a-zA-Z]+) ', line)
        if m:
            codePoint = int(m.group(1), 16)
            value = m.group(2)
            graphemeBreakProperty += [(codePoint, codePoint, value)]
            continue

        # Range of code points?
        m = re.match('([0-9A-F]+)..([0-9A-F]+) +; +([a-zA-Z_]+) ', line)
        if m:
            startCodePoint = int(m.group(1), 16)
            endCodePoint = int(m.group(2), 16)
            value = m.group(3)
            graphemeBreakProperty += [(startCodePoint, endCodePoint, value)]

}%

#include "swift/Basic/Unicode.h"

swift::unicode::GraphemeClusterBreakProperty
swift::unicode::getGraphemeClusterBreakProperty(uint32_t C) {
  // FIXME: replace linear search with a trie lookup.

% for startCodePoint,endCodePoint,value in graphemeBreakProperty:
%   if startCodePoint == 0:
  if (C <= ${endCodePoint})
%   else:
  if (C >= ${startCodePoint} && C <= ${endCodePoint})
%   end
    return GraphemeClusterBreakProperty::${value};
% end

  return GraphemeClusterBreakProperty::Other;
}

%{

# The order should be consistent with 'GraphemeClusterBreakProperty' enum.
anyGraphemePropertyValue = [
  'Other', 'CR', 'LF', 'Control', 'Extend', 'Regional_Indicator', 'Prepend',
  'SpacingMark', 'L', 'V', 'T', 'LV', 'LVT',
]

# Rules to determine extended grapheme cluster boundaries, as defined in
# 'Grapheme Break Chart', ucd/auxiliary/GraphemeBreakTest.html, Unicode 6.3.0.
extendedGraphemeClusterRules = [
  ( [ 'CR' ], 'no_boundary', [ 'LF' ] ),
  ( [ 'Control', 'CR', 'LF' ], 'boundary', anyGraphemePropertyValue ),
  ( anyGraphemePropertyValue, 'boundary', [ 'Control', 'CR', 'LF' ] ),
  ( [ 'L' ], 'no_boundary', [ 'L', 'V', 'LV', 'LVT' ] ),
  ( [ 'LV', 'V' ], 'no_boundary', [ 'V', 'T' ] ),
  ( [ 'LVT', 'T' ], 'no_boundary', [ 'T' ] ),
  ( [ 'Regional_Indicator' ], 'no_boundary', [ 'Regional_Indicator' ] ),
  ( anyGraphemePropertyValue, 'no_boundary', [ 'Extend' ] ),
  ( anyGraphemePropertyValue, 'no_boundary', [ 'SpacingMark' ] ),
  ( [ 'Prepend' ], 'no_boundary', anyGraphemePropertyValue ),
  ( anyGraphemePropertyValue, 'boundary', anyGraphemePropertyValue ),
]

# Expand the rules into a matrix.
extendedGraphemeClusterRulesMatrix = {}
for first in anyGraphemePropertyValue:
    extendedGraphemeClusterRulesMatrix[first] = \
        dict.fromkeys(anyGraphemePropertyValue, None)

for firstList,action,secondList in reversed(extendedGraphemeClusterRules):
    for first in firstList:
        for second in secondList:
            extendedGraphemeClusterRulesMatrix[first][second] = action

# Make sure we can pack one row of the matrix into a 'uint16_t'.
assert(len(anyGraphemePropertyValue) <= 16)

}%

uint16_t swift::unicode::ExtendedGraphemeClusterNoBoundaryRulesMatrix[] = {
% for first in anyGraphemePropertyValue:
%   # Retrieve a row that corresponds to this first code point.
%   row = extendedGraphemeClusterRulesMatrix[first]

%   # Change strings into bits.
%   bits = [ row[second] == 'no_boundary' for second in anyGraphemePropertyValue ]

%   # Pack bits into an integer.
%   packed = sum([ bits[i] * pow(2, i) for i in range(0, len(bits)) ])

  ${packed},
% end
};