90 lines
2.9 KiB
Python
90 lines
2.9 KiB
Python
from .utils import STRING_TYPE
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###{standalone
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class LarkError(Exception):
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pass
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class GrammarError(LarkError):
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pass
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class ParseError(LarkError):
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pass
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class LexError(LarkError):
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pass
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class UnexpectedInput(LarkError):
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pos_in_stream = None
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def get_context(self, text, span=40):
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pos = self.pos_in_stream
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start = max(pos - span, 0)
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end = pos + span
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before = text[start:pos].rsplit('\n', 1)[-1]
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after = text[pos:end].split('\n', 1)[0]
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return before + after + '\n' + ' ' * len(before) + '^\n'
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def match_examples(self, parse_fn, examples):
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""" Given a parser instance and a dictionary mapping some label with
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some malformed syntax examples, it'll return the label for the
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example that bests matches the current error.
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"""
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assert self.state is not None, "Not supported for this exception"
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candidate = None
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for label, example in examples.items():
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assert not isinstance(example, STRING_TYPE)
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for malformed in example:
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try:
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parse_fn(malformed)
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except UnexpectedInput as ut:
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if ut.state == self.state:
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try:
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if ut.token == self.token: # Try exact match first
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return label
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except AttributeError:
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pass
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if not candidate:
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candidate = label
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return candidate
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class UnexpectedCharacters(LexError, UnexpectedInput):
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def __init__(self, seq, lex_pos, line, column, allowed=None, considered_tokens=None, state=None):
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message = "No terminal defined for '%s' at line %d col %d" % (seq[lex_pos], line, column)
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self.line = line
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self.column = column
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self.allowed = allowed
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self.considered_tokens = considered_tokens
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self.pos_in_stream = lex_pos
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self.state = state
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message += '\n\n' + self.get_context(seq)
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if allowed:
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message += '\nExpecting: %s\n' % allowed
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super(UnexpectedCharacters, self).__init__(message)
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class UnexpectedToken(ParseError, UnexpectedInput):
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def __init__(self, token, expected, considered_rules=None, state=None):
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self.token = token
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self.expected = expected # XXX str shouldn't necessary
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self.line = getattr(token, 'line', '?')
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self.column = getattr(token, 'column', '?')
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self.considered_rules = considered_rules
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self.state = state
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self.pos_in_stream = getattr(token, 'pos_in_stream', None)
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message = ("Unexpected token %r at line %s, column %s.\n"
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"Expected one of: \n\t* %s\n"
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% (token, self.line, self.column, '\n\t* '.join(self.expected)))
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super(UnexpectedToken, self).__init__(message)
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###}
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