263 lines
9.9 KiB
Python
263 lines
9.9 KiB
Python
# -*- coding: utf-8 -*-
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"""
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pygments.lexers.tnt
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~~~~~~~~~~~~~~~~~~~
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Lexer for Typographic Number Theory.
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:copyright: Copyright 2006-2020 by the Pygments team, see AUTHORS.
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:license: BSD, see LICENSE for details.
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"""
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import re
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from pygments.lexer import Lexer
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from pygments.token import Text, Comment, Operator, Keyword, Name, Number, \
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Punctuation, Error
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__all__ = ['TNTLexer']
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class TNTLexer(Lexer):
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"""
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Lexer for Typographic Number Theory, as described in the book
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Gödel, Escher, Bach, by Douglas R. Hofstadter,
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or as summarized here:
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https://github.com/Kenny2github/language-tnt/blob/master/README.md#summary-of-tnt
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.. versionadded:: 2.7
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"""
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name = 'Typographic Number Theory'
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aliases = ['tnt']
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filenames = ['*.tnt']
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cur = []
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LOGIC = set('⊃→]&∧^|∨Vv')
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OPERATORS = set('+.⋅*')
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VARIABLES = set('abcde')
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PRIMES = set("'′")
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NEGATORS = set('~!')
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QUANTIFIERS = set('AE∀∃')
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NUMBERS = set('0123456789')
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WHITESPACE = set('\t \v\n')
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RULES = re.compile('''(?xi)
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joining | separation | double-tilde | fantasy\\ rule
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| carry[- ]over(?:\\ of)?(?:\\ line)?\\ ([0-9]+) | detachment
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| contrapositive | De\\ Morgan | switcheroo
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| specification | generalization | interchange
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| existence | symmetry | transitivity
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| add\\ S | drop\\ S | induction
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| axiom\\ ([1-5]) | premise | push | pop
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''')
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LINENOS = re.compile(r'(?:[0-9]+)(?:(?:, ?|,? and )(?:[0-9]+))*')
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COMMENT = re.compile(r'\[[^\n\]]+\]')
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def __init__(self, *args, **kwargs):
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Lexer.__init__(self, *args, **kwargs)
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self.cur = []
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def whitespace(self, start, text, required=False):
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"""Tokenize whitespace."""
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end = start
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try:
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while text[end] in self.WHITESPACE:
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end += 1
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except IndexError:
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end = len(text)
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if required:
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assert end != start
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if end != start:
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self.cur.append((start, Text, text[start:end]))
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return end
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def variable(self, start, text):
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"""Tokenize a variable."""
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assert text[start] in self.VARIABLES
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end = start+1
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while text[end] in self.PRIMES:
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end += 1
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self.cur.append((start, Name.Variable, text[start:end]))
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return end
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def term(self, start, text):
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"""Tokenize a term."""
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if text[start] == 'S': # S...S(...) or S...0
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end = start+1
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while text[end] == 'S':
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end += 1
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self.cur.append((start, Number.Integer, text[start:end]))
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return self.term(end, text)
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if text[start] == '0': # the singleton 0
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self.cur.append((start, Number.Integer, text[start]))
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return start+1
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if text[start] in self.VARIABLES: # a''...
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return self.variable(start, text)
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if text[start] == '(': # (...+...)
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self.cur.append((start, Punctuation, text[start]))
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start = self.term(start+1, text)
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assert text[start] in self.OPERATORS
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self.cur.append((start, Operator, text[start]))
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start = self.term(start+1, text)
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assert text[start] == ')'
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self.cur.append((start, Punctuation, text[start]))
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return start+1
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raise AssertionError # no matches
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def formula(self, start, text):
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"""Tokenize a formula."""
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if text[start] in self.NEGATORS: # ~<...>
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end = start+1
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while text[end] in self.NEGATORS:
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end += 1
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self.cur.append((start, Operator, text[start:end]))
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return self.formula(end, text)
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if text[start] in self.QUANTIFIERS: # Aa:<...>
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self.cur.append((start, Keyword.Declaration, text[start]))
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start = self.variable(start+1, text)
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assert text[start] == ':'
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self.cur.append((start, Punctuation, text[start]))
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return self.formula(start+1, text)
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if text[start] == '<': # <...&...>
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self.cur.append((start, Punctuation, text[start]))
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start = self.formula(start+1, text)
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assert text[start] in self.LOGIC
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self.cur.append((start, Operator, text[start]))
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start = self.formula(start+1, text)
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assert text[start] == '>'
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self.cur.append((start, Punctuation, text[start]))
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return start+1
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# ...=...
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start = self.term(start, text)
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assert text[start] == '='
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self.cur.append((start, Operator, text[start]))
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start = self.term(start+1, text)
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return start
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def rule(self, start, text):
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"""Tokenize a rule."""
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match = self.RULES.match(text, start)
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assert match is not None
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groups = sorted(match.regs[1:]) # exclude whole match
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for group in groups:
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if group[0] >= 0: # this group matched
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self.cur.append((start, Keyword, text[start:group[0]]))
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self.cur.append((group[0], Number.Integer,
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text[group[0]:group[1]]))
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if group[1] != match.end():
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self.cur.append((group[1], Keyword,
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text[group[1]:match.end()]))
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break
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else:
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self.cur.append((start, Keyword, text[start:match.end()]))
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return match.end()
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def lineno(self, start, text):
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"""Tokenize a line referral."""
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end = start
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while text[end] not in self.NUMBERS:
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end += 1
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self.cur.append((start, Punctuation, text[start]))
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self.cur.append((start+1, Text, text[start+1:end]))
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start = end
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match = self.LINENOS.match(text, start)
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assert match is not None
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assert text[match.end()] == ')'
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self.cur.append((match.start(), Number.Integer, match.group(0)))
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self.cur.append((match.end(), Punctuation, text[match.end()]))
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return match.end() + 1
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def error_till_line_end(self, start, text):
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"""Mark everything from ``start`` to the end of the line as Error."""
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end = start
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try:
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while text[end] != '\n': # there's whitespace in rules
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end += 1
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except IndexError:
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end = len(text)
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if end != start:
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self.cur.append((start, Error, text[start:end]))
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end = self.whitespace(end, text)
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return end
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def get_tokens_unprocessed(self, text):
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"""Returns a list of TNT tokens."""
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self.cur = []
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start = end = self.whitespace(0, text)
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while start <= end < len(text):
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try:
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# try line number
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while text[end] in self.NUMBERS:
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end += 1
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if end != start: # actual number present
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self.cur.append((start, Number.Integer, text[start:end]))
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# whitespace is required after a line number
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orig = len(self.cur)
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try:
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start = end = self.whitespace(end, text, True)
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except AssertionError:
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del self.cur[orig:]
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start = end = self.error_till_line_end(end, text)
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continue
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# at this point it could be a comment
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match = self.COMMENT.match(text, start)
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if match is not None:
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self.cur.append((start, Comment, text[start:match.end()]))
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start = end = match.end()
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# anything after the closing bracket is invalid
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start = end = self.error_till_line_end(start, text)
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# do not attempt to process the rest
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continue
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del match
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if text[start] in '[]': # fantasy push or pop
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self.cur.append((start, Keyword, text[start]))
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start += 1
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end += 1
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else:
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# one formula, possibly containing subformulae
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orig = len(self.cur)
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try:
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start = end = self.formula(start, text)
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except AssertionError: # not well-formed
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del self.cur[orig:]
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while text[end] not in self.WHITESPACE:
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end += 1
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self.cur.append((start, Error, text[start:end]))
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start = end
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# skip whitespace after formula
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orig = len(self.cur)
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try:
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start = end = self.whitespace(end, text, True)
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except AssertionError:
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del self.cur[orig:]
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start = end = self.error_till_line_end(start, text)
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continue
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# rule proving this formula a theorem
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orig = len(self.cur)
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try:
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start = end = self.rule(start, text)
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except AssertionError:
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del self.cur[orig:]
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start = end = self.error_till_line_end(start, text)
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continue
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# skip whitespace after rule
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start = end = self.whitespace(end, text)
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# line marker
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if text[start] == '(':
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orig = len(self.cur)
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try:
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start = end = self.lineno(start, text)
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except AssertionError:
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del self.cur[orig:]
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start = end = self.error_till_line_end(start, text)
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continue
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start = end = self.whitespace(start, text)
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except IndexError:
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try:
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del self.cur[orig:]
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except NameError:
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pass # if orig was never defined, fine
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self.error_till_line_end(start, text)
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return self.cur
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