grammar_options.md

back to index

grammar::options

grammar's options is a plain struct which can be passed to a grammar when it is instantiated.

attributes

bool transform_negation;

If this is true, and it is true by default, any negation in a grammar is transformed into a negation tracking rule when the grammar is instantiated. false is used for example to instantiate grammar from a generated parser because its rules are already product of this negation transormation.

bool auto_disambiguate;

This is true by default. Parser disambiguates parse trees according to an order of production rule appearance in the grammar. Setting this to false would make parser to provide all possible parse trees.

This can be also disabled by TGF directive @disable disambiguation.

std::set<size_t> nodisambig_list;

If auto_disambiguate is set to true this list contains nonterminal ids of symbols we don't want to disambiguate and we want to keep ambiguity in the resulting parse forest.

This list can be set by TGF directive: @ambiguous symbol1, symbol2.

shaping_options shaping;

parsed tree shaping_options