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author | S. Solomon Darnell | 2025-03-28 21:52:21 -0500 |
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committer | S. Solomon Darnell | 2025-03-28 21:52:21 -0500 |
commit | 4a52a71956a8d46fcb7294ac71734504bb09bcc2 (patch) | |
tree | ee3dc5af3b6313e921cd920906356f5d4febc4ed /.venv/lib/python3.12/site-packages/lark/parsers/earley_common.py | |
parent | cc961e04ba734dd72309fb548a2f97d67d578813 (diff) | |
download | gn-ai-master.tar.gz |
Diffstat (limited to '.venv/lib/python3.12/site-packages/lark/parsers/earley_common.py')
-rw-r--r-- | .venv/lib/python3.12/site-packages/lark/parsers/earley_common.py | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/lark/parsers/earley_common.py b/.venv/lib/python3.12/site-packages/lark/parsers/earley_common.py new file mode 100644 index 00000000..6bd614ba --- /dev/null +++ b/.venv/lib/python3.12/site-packages/lark/parsers/earley_common.py @@ -0,0 +1,75 @@ +"This module implements an Earley Parser" + +# The parser uses a parse-forest to keep track of derivations and ambiguations. +# When the parse ends successfully, a disambiguation stage resolves all ambiguity +# (right now ambiguity resolution is not developed beyond the needs of lark) +# Afterwards the parse tree is reduced (transformed) according to user callbacks. +# I use the no-recursion version of Transformer, because the tree might be +# deeper than Python's recursion limit (a bit absurd, but that's life) +# +# The algorithm keeps track of each state set, using a corresponding Column instance. +# Column keeps track of new items using NewsList instances. +# +# Author: Erez Shinan (2017) +# Email : erezshin@gmail.com + +from ..grammar import NonTerminal, Terminal + +class Item(object): + "An Earley Item, the atom of the algorithm." + + __slots__ = ('s', 'rule', 'ptr', 'start', 'is_complete', 'expect', 'previous', 'node', '_hash') + def __init__(self, rule, ptr, start): + self.is_complete = len(rule.expansion) == ptr + self.rule = rule # rule + self.ptr = ptr # ptr + self.start = start # j + self.node = None # w + if self.is_complete: + self.s = rule.origin + self.expect = None + self.previous = rule.expansion[ptr - 1] if ptr > 0 and len(rule.expansion) else None + else: + self.s = (rule, ptr) + self.expect = rule.expansion[ptr] + self.previous = rule.expansion[ptr - 1] if ptr > 0 and len(rule.expansion) else None + self._hash = hash((self.s, self.start)) + + def advance(self): + return Item(self.rule, self.ptr + 1, self.start) + + def __eq__(self, other): + return self is other or (self.s == other.s and self.start == other.start) + + def __hash__(self): + return self._hash + + def __repr__(self): + before = ( expansion.name for expansion in self.rule.expansion[:self.ptr] ) + after = ( expansion.name for expansion in self.rule.expansion[self.ptr:] ) + symbol = "{} ::= {}* {}".format(self.rule.origin.name, ' '.join(before), ' '.join(after)) + return '%s (%d)' % (symbol, self.start) + + +class TransitiveItem(Item): + __slots__ = ('recognized', 'reduction', 'column', 'next_titem') + def __init__(self, recognized, trule, originator, start): + super(TransitiveItem, self).__init__(trule.rule, trule.ptr, trule.start) + self.recognized = recognized + self.reduction = originator + self.column = start + self.next_titem = None + self._hash = hash((self.s, self.start, self.recognized)) + + def __eq__(self, other): + if not isinstance(other, TransitiveItem): + return False + return self is other or (type(self.s) == type(other.s) and self.s == other.s and self.start == other.start and self.recognized == other.recognized) + + def __hash__(self): + return self._hash + + def __repr__(self): + before = ( expansion.name for expansion in self.rule.expansion[:self.ptr] ) + after = ( expansion.name for expansion in self.rule.expansion[self.ptr:] ) + return '{} : {} -> {}* {} ({}, {})'.format(self.recognized.name, self.rule.origin.name, ' '.join(before), ' '.join(after), self.column, self.start) |