Experimental parser: break KeyEncoding off into its own file

tools/lexer_generator/encoding.py

+# Copyright 2013 the V8 project authors. All rights reserved.
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+#       copyright notice, this list of conditions and the following
+#       disclaimer in the documentation and/or other materials provided
+#       with the distribution.
+#     * Neither the name of Google Inc. nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+from types import IntType
+from itertools import chain
+from string import printable
+from action import Term
+
+class KeyEncoding(object):
+
+  __encodings = {}
+
+  __printable_cache = {
+    ord('\t') : '\\t',
+    ord('\n') : '\\n',
+    ord('\r') : '\\r',
+  }
+
+  @staticmethod
+  def to_str(encoding, x):
+    assert not encoding or encoding.in_primary_range(x, x)
+    if x > 127:
+      return str(x)
+    if not x in KeyEncoding.__printable_cache:
+      res = "'%s'" % chr(x) if chr(x) in printable else str(x)
+      KeyEncoding.__printable_cache[x] = res
+    return KeyEncoding.__printable_cache[x]
+
+  @staticmethod
+  def get(name):
+    if not KeyEncoding.__encodings:
+      Latin1Encoding()
+      Utf16Encoding()
+      Utf8Encoding()
+    return KeyEncoding.__encodings[name]
+
+  def __init__(self, name, primary_range, named_ranges, predefined_ranges):
+    assert not name in KeyEncoding.__encodings
+    assert primary_range[0] <= primary_range[1]
+    KeyEncoding.__encodings[name] = self
+    self.__name = name
+    self.__primary_range = primary_range
+    self.__lower_bound = primary_range[0]
+    self.__upper_bound = primary_range[1]
+    self.__primary_range_component = self.numeric_range_term(primary_range[0],
+                                                             primary_range[1])
+    self.__named_ranges = {
+      k : Term('NAMED_RANGE_KEY', k) for k in named_ranges }
+    def f(v):
+      if len(v) == 2:
+        return self.numeric_range_term(v[0], v[1])
+      elif len(v) == 1:
+        assert v[0] in self.__named_ranges
+        return self.__named_ranges[v[0]]
+      raise Exception('bad args %s' % str(v))
+    self.__predefined_ranges = {
+      k : map(f, v) for k, v in predefined_ranges.iteritems() }
+
+  def name(self):
+    return self.__name
+
+  def lower_bound(self):
+    return self.__lower_bound
+
+  def upper_bound(self):
+    return self.__upper_bound
+
+  def primary_range(self):
+    return self.__primary_range
+
+  def named_range(self, name):
+    ranges = self.__named_ranges
+    return Term.empty_term() if not name in ranges else ranges[name]
+
+  def named_range_iter(self):
+    return self.__named_range.iteritems()
+
+  def named_range_key_iter(self):
+    return self.__named_ranges.iterkeys()
+
+  def named_range_value_iter(self):
+    return self.__named_ranges.itervalues()
+
+  def predefined_range_iter(self, name):
+    ranges = self.__predefined_ranges
+    return None if not name in ranges else iter(ranges[name])
+
+  def __primary_range_iter(self):
+    yield self.__primary_range_component
+
+  def all_components_iter(self):
+    return chain(self.__primary_range_iter(), self.__named_ranges.itervalues())
+
+  def is_primary_range(self, r):
+    assert len(r) == 2
+    return self.in_primary_range(r[0], r[1])
+
+  def in_primary_range(self, a, b):
+    return self.lower_bound() <= a and b <= self.upper_bound()
+
+  def numeric_range_term(self, a, b):
+    assert type(a) == IntType and type(b) == IntType
+    assert self.in_primary_range(a, b)
+    return Term('NUMERIC_RANGE_KEY', a, b)
+
+class Latin1Encoding(KeyEncoding):
+
+  def __init__(self):
+    super(Latin1Encoding, self).__init__(
+      'latin1',
+      (0, 255),
+      [],
+      {
+        'whitespace':
+          [(9, 9), (11, 12), (32, 32), (133, 133), (160, 160)],
+        'letter':
+          [(65, 90), (97, 122), (170, 170), (181, 181),
+           (186, 186), (192, 214), (216, 246), (248, 255)],
+        'line_terminator':
+          [(10, 10), (13, 13)],
+        'identifier_part_not_letter':
+          [(48, 57), (95, 95)]
+      })
+
+class Utf16Encoding(KeyEncoding):
+
+  def __init__(self):
+    super(Utf16Encoding, self).__init__(
+      'utf16',
+      (0, 255),
+      ['non_primary_whitespace',
+       'non_primary_letter',
+       'non_primary_identifier_part_not_letter',
+       'non_primary_line_terminator',
+       'non_primary_everything_else'],
+      {
+        'whitespace':
+          [(9, 9), (11, 12), (32, 32), (133, 133), (160, 160),
+           ('non_primary_whitespace',)],
+        'letter':
+          [(65, 90), (97, 122), (170, 170), (181, 181),
+           (186, 186), (192, 214), (216, 246), (248, 255),
+           ('non_primary_letter',)],
+        'line_terminator':
+          [(10, 10), (13, 13), ('non_primary_line_terminator',)],
+        'identifier_part_not_letter':
+          [(48, 57), (95, 95), ('non_primary_identifier_part_not_letter',)],
+      })
+
+class Utf8Encoding(KeyEncoding):
+
+  def __init__(self):
+    super(Utf8Encoding, self).__init__(
+      'utf8',
+      (0, 127),
+      ['non_primary_whitespace',
+       'non_primary_letter',
+       'non_primary_identifier_part_not_letter',
+       'non_primary_line_terminator',
+       'non_primary_everything_else'],
+      {
+        'whitespace':
+          [(9, 9), (11, 12), (32, 32), ('non_primary_whitespace',)],
+        'letter':
+          [(65, 90), (97, 122), ('non_primary_letter',)],
+        'line_terminator':
+          [(10, 10), (13, 13), ('non_primary_line_terminator',)],
+        'identifier_part_not_letter':
+          [(48, 57), (95, 95), ('non_primary_identifier_part_not_letter',)],
+      })