672 lines
28 KiB
Python
Executable File
672 lines
28 KiB
Python
Executable File
import re
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valid_name_re = re.compile('^[a-zA-Z_][a-zA-Z0-9_]*$')
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reserved_names = ['start', 'middle', 'end', 'null']
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class RuleContext:
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# to be clear:
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# x, y: where the rule processing began
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# rule: the rule which began
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# flag: a signal to be used to resume the rule correctly
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# context: the previous rule namespace(s)
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# matchd: the dictionary returned by the rule's matching
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def __init__(self, y, x, rule, flag, context, matchd):
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self.y = y
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self.x = x
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self.rule = rule
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self.flag = flag
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self.context = context
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self.matchd = matchd
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class Token(object):
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def __init__(self, name, rule, y, x, s, **vargs):
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self.name = name
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self.rule = rule
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self.y = y
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self.x = x
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self.string = s
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self.vargs = vargs
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def copy(self):
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return Token(self.name, None, self.y, self.x, self.string, **self.vargs)
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def add_to_string(self, s):
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self.string += s
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def end_x(self):
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return self.x + len(self.string)
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def __eq__(self, other):
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return (self.y == other.y and
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self.x == other.x and
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self.string == other.string and
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self.name == other.name and
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self.vargs == other.vargs)
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def __repr__(self):
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if len(self.string) < 10:
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s = self.string
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else:
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s = self.string[:10] + '...'
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return "<Token(%r, %r, %d, %d, %r)>" % (self.name, self.rule, self.y, self.x, s)
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def render(self):
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return (self,)
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class Rule:
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name = 'abstract'
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def match(self, lexer, context=[], d={}):
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raise Exception, "%s rule cannot match!" % self.name
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def make_token(self, lexer, s, name, **vargs):
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return Token(name, self, lexer.y, lexer.x, s, **vargs)
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class ConstantRule(Rule):
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def __init__(self, name, constant):
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assert valid_name_re.match(name), 'invalid name %r' % name
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assert name not in reserved_names, "reserved rule name: %r" % name
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self.name = name
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self.constant = constant
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def match(self, lexer, context=[], d={}):
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if lexer.lines[lexer.y][lexer.x:].startswith(self.constant):
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name = '.'.join(context + [self.name])
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lexer.add_token(self.make_token(lexer, self.constant, name, grammar=lexer.grammar))
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lexer.x += len(self.constant)
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return True
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else:
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return False
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class PatternRule(Rule):
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def __init__(self, name, pattern):
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assert valid_name_re.match(name), 'invalid name %r' % name
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assert name not in reserved_names, "reserved rule name: %r" % name
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self.name = name
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self.pattern = pattern
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self.re = re.compile(pattern)
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def match(self, lexer, context=[], d={}):
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m = self.re.match(lexer.lines[lexer.y], lexer.x)
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if m:
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name = '.'.join(context + [self.name])
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lexer.add_token(self.make_token(lexer, m.group(0), name, grammar=lexer.grammar))
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lexer.x += len(m.group(0))
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return True
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else:
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return False
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class ContextPatternRule(Rule):
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def __init__(self, name, pattern, fallback):
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assert valid_name_re.match(name), 'invalid name %r' % name
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assert name not in reserved_names, "reserved rule name: %r" % name
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self.name = name
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self.pattern = pattern
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self.fallback = fallback
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self.fallback_re = re.compile(fallback)
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def match(self, lexer, context=[], d={}):
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try:
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r = re.compile(self.pattern % d)
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except KeyError:
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r = self.fallback_re
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m = r.match(lexer.lines[lexer.y], lexer.x)
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if m:
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name = '.'.join(context + [self.name])
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lexer.add_token(self.make_token(lexer, m.group(0), name, grammar=lexer.grammar))
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lexer.x += len(m.group(0))
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return True
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else:
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return False
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class RegionRule(Rule):
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def __init__(self, name, start, grammar, end):
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assert valid_name_re.match(name), 'invalid name %r' % name
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assert name not in reserved_names, "reserved rule name: %r" % name
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self.name = name
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self.start = start
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self.grammar = grammar
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self.end = end
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self.start_re = re.compile(start)
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def _add_from_regex(self, context, name, lexer, m, grammar):
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t_name = '.'.join(context + [self.name, name])
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t = self.make_token(lexer, m.group(0), t_name, grammar=grammar)
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lexer.add_token(t)
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lexer.x += len(m.group(0))
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def resume(self, lexer, context, flag, d, rulecontexts):
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assert rulecontexts, "can't resume without rulecontexts!"
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self._match(lexer, context, d, None, rulecontexts)
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return True
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def match(self, lexer, context=[], d={}):
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# see if we can match our start token
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m = self.start_re.match(lexer.lines[lexer.y], lexer.x)
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if m:
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# region was match, so let's do this
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return self._match(lexer, context, m.groupdict(), m, [])
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else:
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# region was not matched; we never started. so return false
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return False
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def _match(self, lexer, context, d, m, rulecontext=[]):
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# if we have been given rulecontext, then we are going to "resume" a
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# parse that can already be assumed to have started
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reenter = len(rulecontext) > 0
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assert m or reenter
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# first let's do some bookkeeping
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lexer.context.append(RuleContext(lexer.y, lexer.x, self, 'start',
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list(context), dict(d)))
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if m is not None:
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self._add_from_regex(context, 'start', lexer, m, lexer.grammar)
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null_t_name = '.'.join(context + [self.name, 'null'])
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null_t = None
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# if we have an end token, then build it here. notice that it can
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# reference named groups from the start token. if we have no end,
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# well, then, we're never getting out of here alive!
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if self.end:
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end_re = re.compile(self.end % d)
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# ok, so as long as we aren't done (we haven't found an end token),
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# keep reading input
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done = False
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while not done and lexer.y < len(lexer.lines):
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old_y = lexer.y
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# if this line is empty, then we skip it, but here we insert
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# an empty null token just so we have something
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if not reenter and len(lexer.lines[lexer.y]) == 0:
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null_t = Token(null_t_name, None, lexer.y, lexer.x, '')
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lexer.add_token(null_t)
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null_t = None
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# ok, as long as we haven't found the end token, and have more
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# data on the current line to read, we will process tokens
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while not done and lexer.y == old_y and lexer.x < len(lexer.lines[lexer.y]):
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# if we are reentering mid-parse, then that takes precedence
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if reenter:
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reenter = False
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rule2 = rulecontext[0].rule
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context2 = rulecontext[0].context
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d2 = rulecontext[0].matchd
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assert rule2.resume(lexer, context2, d2, rulecontext[1:]), \
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"%r %r %r %r" % (lexer, context2, d2, rulecontext[1:])
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found = True
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null_t = None
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break
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# if we are looking for an end token, then see if we've
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# found it. if so, then we are done!
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if self.end:
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m = end_re.match(lexer.lines[lexer.y], lexer.x)
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if m:
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self._add_from_regex(context, 'end', lexer, m, None)
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done = True
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break
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# ok, we need to check all our rules now, in order. if we
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# find a token, note that we found one and exit the loop
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found = False
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for rule in self.grammar.rules:
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if rule.match(lexer, context + [self.name], d):
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found = True
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null_t = None
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break
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# if we never found a token, then we need to add another
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# character to the current null token (which we should
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# create if it isn't set).
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if not found:
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if null_t is None:
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null_t = Token(null_t_name, None, lexer.y, lexer.x, '')
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lexer.add_token(null_t)
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null_t.add_to_string(lexer.lines[lexer.y][lexer.x])
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lexer.x += 1
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# ok, since we're soon going to be on a different line (or
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# already are), we want a new null token. so forget about the
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# current one (i.e. stop adding to it).
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null_t = None
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# if we're still on the same line at this point (and not done)
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# then that means we're finished with the line and should move
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# on to the next one here
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if not done and old_y == lexer.y:
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lexer.save_context()
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lexer.y += 1
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lexer.x = 0
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# alright, we're finally done procesing the region, so return true
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lexer.context.pop(-1)
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return True
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class DualRegionRule(Rule):
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def __init__(self, name, start, grammar1, middle, grammar2, end):
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assert valid_name_re.match(name), 'invalid name %r' % name
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assert name not in reserved_names, "reserved rule name: %r" % name
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self.name = name
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self.start = start
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self.grammar1 = grammar1
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self.middle = middle
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self.grammar2 = grammar2
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self.end = end
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self.start_re = re.compile(start)
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def _add_from_regex(self, context, name, lexer, m, grammar=None):
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t_name = '.'.join(context + [self.name, name])
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t = self.make_token(lexer, m.group(0), t_name, grammar=grammar)
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lexer.add_token(t)
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lexer.x += len(m.group(0))
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def resume(self, lexer, context, flag, d, rulecontexts):
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if flag == 'start':
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d2 = self._match_first(lexer, context, d, None, rulecontexts)
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d3 = dict(d.items() + d2.items())
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self._match_second(lexer, context, d3, None, rulecontexts)
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return True
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elif flag == 'middle':
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self._match_second(lexer, context, flag, d, None, rulecontexts)
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return True
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else:
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raise Exception, "invalid flag %r" % flag
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def match(self, lexer, context=[], d={}):
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# see if we can match our start token
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m = self.start_re.match(lexer.lines[lexer.y], lexer.x)
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if m:
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# region was match, so let's do this
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d1 = m.groupdict()
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d2 = self._match_first(lexer, context, d1, m, [])
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d3 = dict(d1.items() + d2.items())
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self._match_second(lexer, context, d3, None, [])
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return True
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else:
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# region was not matched; we never started. so return false
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return False
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def _match_first(self, lexer, context, d1, m1, rulecontext=[]):
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# if we have been given rulecontext, then we are going to "resume" a
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# parse that can already be assumed to have started
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reenter = len(rulecontext) > 0
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assert m1 or reenter
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# first let's do some bookkeeping
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lexer.context.append(RuleContext(lexer.y, lexer.x, self, 'start',
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list(context), dict(d1)))
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# ok, so create our start token, and get ready to start reading data
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if m1 is not None:
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self._add_from_regex(context, 'start', lexer, m1, lexer.grammar)
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null_t_name = '.'.join(context + [self.name, 'null'])
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null_t = None
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middle_re = re.compile(self.middle % d1)
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d2 = {}
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# ok, so as long as we aren't done (we haven't found an end token),
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# keep reading input
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done = False
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while not done and lexer.y < len(lexer.lines):
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old_y = lexer.y
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# if this line is empty, then we will skip it, but here weinsert
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# an empty null token just so we have something
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if len(lexer.lines[lexer.y]) == 0:
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null_t = Token(null_t_name, None, lexer.y, lexer.x, '')
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lexer.add_token(null_t)
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null_t = None
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# ok, as long as we haven't found the end token, and have more
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# data on the current line to read, we will process tokens
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while not done and lexer.y == old_y and lexer.x < len(lexer.lines[lexer.y]):
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# if we are reentering mid-parse, then that takes precedence
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if reenter:
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reenter = False
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xrule = rulecontext[0].rule
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xcontext = rulecontext[0].context
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xd = rulecontext[0].matchd
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assert rule2.resume(lexer, xcontext, xd, rulecontext[1:]), \
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"%r %r %r %r" % (lexer, xcontext, xd, rulecontext[1:])
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found = True
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null_t = None
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break
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# see if we have found the middle token. if so, we can then
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# proceed to "stage 2"
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m2 = middle_re.match(lexer.lines[lexer.y], lexer.x)
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if m2:
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d2 = m2.groupdict()
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self._add_from_regex(context, 'middle', lexer, m2, None)
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done = True
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break
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# ok, we need to check all our rules now, in order. if we
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# find a token, note that we found one and exit the loop
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found = False
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for rule in self.grammar1.rules:
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if rule.match(lexer, context + [self.name], d1):
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found = True
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null_t = None
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break
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# if we never found a token, then we need to add another
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# character to the current null token (which we should
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# create if it isn't set).
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if not found:
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if null_t is None:
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null_t = Token(null_t_name, None, lexer.y, lexer.x, '')
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lexer.add_token(null_t)
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null_t.add_to_string(lexer.lines[lexer.y][lexer.x])
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lexer.x += 1
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# ok, since we're soon going to be on a different line (or
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# already are), we want a new null token. so forget about the
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# current one.
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null_t = None
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# if we're still on the same line at this point (and not done)
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# then that means we're finished with the line and should move
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# on to the next one here
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if not done and old_y == lexer.y:
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lexer.save_context()
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lexer.y += 1
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lexer.x = 0
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lexer.context.pop(-1)
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return d2
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def _match_second(self, lexer, context, d3, m, rulecontext=[]):
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# if we have been given rulecontext, then we are going to "resume" a
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# parse that can already be assumed to have started
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reenter = len(rulecontext) > 0
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# ok stage 2 is like stage 1, only we are looking for end tokens
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# instead of middle tokens
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null_t_name = '.'.join(context + [self.name, 'null'])
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null_t = None
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end_re = re.compile(self.end % d3)
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lexer.context.append(RuleContext(lexer.y, lexer.x, self, 'middle',
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list(context), dict(d3)))
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# ok, so as long as we aren't done (we haven't found an end token),
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# keep reading input
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done = False
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while not done and lexer.y < len(lexer.lines):
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old_y = lexer.y
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# if we are reentering mid-parse, then that takes precedence
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if reenter:
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reenter = False
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xrule = rulecontext[0].rule
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xcontext = rulecontext[0].context
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xd = rulecontext[0].matchd
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assert rule2.resume(lexer, xcontext, xd, rulecontext[1:]), \
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"%r %r %r %r" % (lexer, xcontext, xd, rulecontext[1:])
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found = True
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null_t = None
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break
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# if this line is empty, then we will skip it, but here weinsert
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# an empty null token just so we have something
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if len(lexer.lines[lexer.y]) == 0:
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null_t = Token(null_t_name, None, lexer.y, lexer.x, '')
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lexer.add_token(null_t)
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null_t = None
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# ok, as long as we haven't found the end token, and have more
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# data on the current line to read, we will process tokens
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while not done and lexer.y == old_y and lexer.x < len(lexer.lines[lexer.y]):
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# see if we have found the middle token. if so, we can then
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# proceed to "stage 2"
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m3 = end_re.match(lexer.lines[lexer.y], lexer.x)
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if m3:
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self._add_from_regex(context, 'end', lexer, m3, None)
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done = True
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break
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# ok, we need to check all our rules now, in order. if we
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# find a token, note that we found one and exit the loop
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found = False
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for rule in self.grammar2.rules:
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if rule.match(lexer, context + [self.name], d3):
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found = True
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null_t = None
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break
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# if we never found a token, then we need to add another
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# character to the current null token (which we should
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# create if it isn't set).
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if not found:
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if null_t is None:
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null_t = Token(null_t_name, None, lexer.y, lexer.x, '')
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lexer.add_token(null_t)
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null_t.add_to_string(lexer.lines[lexer.y][lexer.x])
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lexer.x += 1
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# ok, since we're soon going to be on a different line (or
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# already are), we want a new null token. so forget about the
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# current one.
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null_t = None
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# if we're still on the same line at this point (and not done)
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# then that means we're finished with the line and should move
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# on to the next one here
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if not done and old_y == lexer.y:
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lexer.save_context()
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lexer.y += 1
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lexer.x = 0
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# alright, we're finally done processing; return true
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lexer.context.pop(-1)
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return True
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# def matchOLD(self, lexer, context=[], d={}):
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# m1 = self.start_re.match(lexer.lines[lexer.y], lexer.x)
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# # see if we can match out start token
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# if m1:
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# # ok, so create our start token, and get ready to start reading data
|
|
# self._add_from_regex(context, 'start', lexer, m1, lexer.grammar)
|
|
# null_t_name = '.'.join(context + [self.name, 'null'])
|
|
# null_t = None
|
|
#
|
|
# d1 = m1.groupdict()
|
|
# lexer.context.append(RuleContext(lexer.y, lexer.x, self, 'start',
|
|
# list(context), dict(d1)))
|
|
# d2 = {}
|
|
# middle_re = re.compile(self.middle % d1)
|
|
#
|
|
# # ok, so as long as we aren't done (we haven't found an end token),
|
|
# # keep reading input
|
|
# done = False
|
|
# while not done and lexer.y < len(lexer.lines):
|
|
# old_y = lexer.y
|
|
# # if this line is empty, then we will skip it, but here weinsert
|
|
# # an empty null token just so we have something
|
|
# if len(lexer.lines[lexer.y]) == 0:
|
|
# null_t = Token(null_t_name, None, lexer.y, lexer.x, '')
|
|
# lexer.add_token(null_t)
|
|
# null_t = None
|
|
#
|
|
# # ok, as long as we haven't found the end token, and have more
|
|
# # data on the current line to read, we will process tokens
|
|
# while not done and lexer.y == old_y and lexer.x < len(lexer.lines[lexer.y]):
|
|
# # see if we have found the middle token. if so, we can then
|
|
# # proceed to "stage 2"
|
|
# m2 = middle_re.match(lexer.lines[lexer.y], lexer.x)
|
|
# if m2:
|
|
# d2 = m2.groupdict()
|
|
# self._add_from_regex(context, 'middle', lexer, m2, None)
|
|
# done = True
|
|
# break
|
|
#
|
|
# # ok, we need to check all our rules now, in order. if we
|
|
# # find a token, note that we found one and exit the loop
|
|
# found = False
|
|
# for rule in self.grammar1.rules:
|
|
# if rule.match(lexer, context + [self.name], d1):
|
|
# found = True
|
|
# null_t = None
|
|
# break
|
|
#
|
|
# # if we never found a token, then we need to add another
|
|
# # character to the current null token (which we should
|
|
# # create if it isn't set).
|
|
# if not found:
|
|
# if null_t is None:
|
|
# null_t = Token(null_t_name, None, lexer.y, lexer.x, '')
|
|
# lexer.add_token(null_t)
|
|
# null_t.add_to_string(lexer.lines[lexer.y][lexer.x])
|
|
# lexer.x += 1
|
|
#
|
|
# # ok, since we're soon going to be on a different line (or
|
|
# # already are), we want a new null token. so forget about the
|
|
# # current one.
|
|
# null_t = None
|
|
#
|
|
# # if we're still on the same line at this point (and not done)
|
|
# # then that means we're finished with the line and should move
|
|
# # on to the next one here
|
|
# if not done and old_y == lexer.y:
|
|
# lexer.save_context()
|
|
# lexer.y += 1
|
|
# lexer.x = 0
|
|
#
|
|
# # ok stage 2 is like stage 1, only we are looking for end tokens
|
|
# # instead of middle tokens
|
|
# d3 = dict(d1.items() + d2.items())
|
|
# end_re = re.compile(self.end % d3)
|
|
# lexer.context.pop(-1)
|
|
# lexer.context.append(RuleContext(lexer.y, lexer.x, self, 'middle',
|
|
# list(context), dict(d3)))
|
|
#
|
|
# # ok, so as long as we aren't done (we haven't found an end token),
|
|
# # keep reading input
|
|
# done = False
|
|
# while not done and lexer.y < len(lexer.lines):
|
|
# old_y = lexer.y
|
|
# # if this line is empty, then we will skip it, but here weinsert
|
|
# # an empty null token just so we have something
|
|
# if len(lexer.lines[lexer.y]) == 0:
|
|
# null_t = Token(null_t_name, None, lexer.y, lexer.x, '')
|
|
# lexer.add_token(null_t)
|
|
# null_t = None
|
|
#
|
|
# # ok, as long as we haven't found the end token, and have more
|
|
# # data on the current line to read, we will process tokens
|
|
# while not done and lexer.y == old_y and lexer.x < len(lexer.lines[lexer.y]):
|
|
# # see if we have found the middle token. if so, we can then
|
|
# # proceed to "stage 2"
|
|
# m3 = end_re.match(lexer.lines[lexer.y], lexer.x)
|
|
# if m3:
|
|
# self._add_from_regex(context, 'end', lexer, m3, None)
|
|
# done = True
|
|
# break
|
|
#
|
|
# # ok, we need to check all our rules now, in order. if we
|
|
# # find a token, note that we found one and exit the loop
|
|
# found = False
|
|
# for rule in self.grammar2.rules:
|
|
# if rule.match(lexer, context + [self.name], d3):
|
|
# found = True
|
|
# null_t = None
|
|
# break
|
|
#
|
|
# # if we never found a token, then we need to add another
|
|
# # character to the current null token (which we should
|
|
# # create if it isn't set).
|
|
# if not found:
|
|
# if null_t is None:
|
|
# null_t = Token(null_t_name, None, lexer.y, lexer.x, '')
|
|
# lexer.add_token(null_t)
|
|
# null_t.add_to_string(lexer.lines[lexer.y][lexer.x])
|
|
# lexer.x += 1
|
|
#
|
|
# # ok, since we're soon going to be on a different line (or
|
|
# # already are), we want a new null token. so forget about the
|
|
# # current one.
|
|
# null_t = None
|
|
#
|
|
# # if we're still on the same line at this point (and not done)
|
|
# # then that means we're finished with the line and should move
|
|
# # on to the next one here
|
|
# if not done and old_y == lexer.y:
|
|
# lexer.save_context()
|
|
# lexer.y += 1
|
|
# lexer.x = 0
|
|
#
|
|
# # alright, we're finally done processing; return true
|
|
# lexer.context.pop(-1)
|
|
# return True
|
|
# else:
|
|
# # dual region was not matched; we never started. so return false
|
|
# return False
|
|
|
|
class Grammar:
|
|
rules = []
|
|
def __init__(self):
|
|
for rule in self.rules:
|
|
if hasattr(rule, 'grammar') and rule.grammar is None:
|
|
rule.grammar = self
|
|
|
|
class Lexer:
|
|
def __init__(self, name, grammar):
|
|
self.name = name
|
|
self.grammar = grammar
|
|
self.y = 0
|
|
self.x = 0
|
|
self.lines = None
|
|
self.tokens = []
|
|
|
|
self.context = []
|
|
self.line_contexts = {}
|
|
|
|
def add_token(self, t):
|
|
self.tokens.append(t)
|
|
|
|
def lex(self, lines, y=0, x=0):
|
|
self.y = y
|
|
self.x = x
|
|
self.lines = lines
|
|
self.tokens = []
|
|
|
|
self.context = []
|
|
self.line_contexts = {}
|
|
|
|
def resume(self, lines, y=0, x=0, rulecontexts=[]):
|
|
if len(rulecontexts) == 0:
|
|
self.lex(lines, y, x)
|
|
else:
|
|
self.y = y
|
|
self.x = x
|
|
self.lines = lines
|
|
self.tokens = []
|
|
rc = rulecontexts[0]
|
|
rc.rule.resume(self, rc.context, rc.flag, rc.matchd, rulecontexts[1:])
|
|
|
|
def __iter__(self):
|
|
if self.lines is None:
|
|
raise Exception, "no lines to lex"
|
|
return self
|
|
|
|
def save_context(self):
|
|
self.line_contexts[self.y] = list(self.context)
|
|
|
|
def next(self):
|
|
null_t_name = 'null'
|
|
null_t = None
|
|
|
|
if self.tokens:
|
|
return self.tokens.pop(0)
|
|
|
|
while self.y < len(self.lines):
|
|
line = self.lines[self.y]
|
|
while self.x < len(line):
|
|
curr_t = None
|
|
for rule in self.grammar.rules:
|
|
if rule.match(self):
|
|
assert self.tokens, "match rendered no tokens?"
|
|
return self.tokens.pop(0)
|
|
if null_t is None:
|
|
null_t = Token(null_t_name, None, self.y, self.x, '')
|
|
self.add_token(null_t)
|
|
null_t.add_to_string(line[self.x])
|
|
self.x += 1
|
|
self.save_context()
|
|
null_t = None
|
|
self.y += 1
|
|
self.x = 0
|
|
|
|
if self.tokens:
|
|
return self.tokens.pop(0)
|
|
else:
|
|
raise StopIteration
|