EST_SCFG_Chart Class Reference

#include <include/EST_SCFG_Chart.h>

Public Member Functions
Constructor and initialisation functions
	EST_SCFG_Chart ()
	~EST_SCFG_Chart ()
Grammar and parse string initialisation functions
void	set_grammar_rules (LISP r)
	Initialize from LISP rules set.
void	set_grammar_rules (EST_SCFG &grammar)
	Initialize from existing {EST_SCFG} grammar.
void	setup_wfst (EST_Relation *s, const EST_String &name="name")
void	setup_wfst (EST_Item *s, EST_Item *e, const EST_String &name="name")
parsing functions
void	parse ()
	Parses the loaded WFST with the loaded grammar.
LISP	find_parse ()
	Return the parse in full LISP form.
void	extract_parse (EST_Relation *syn, EST_Relation *word, int force=0)
	Extract parse tree and add it to syn linking leafs to word.
void	extract_parse (EST_Relation *syn, EST_Item *s, EST_Item *e, int force=0)
	Extract parse tree and add it to syn linking leafs to items s to e.

Detailed Description

A class for parsing with a probabilistic grammars.

The chart (sort of closer to CKY table) consists of indexes of edges indexed by vertex number of mother non-terminal.

The initial values (well-formed substring table) are taken from an {EST_Stream} with a given feature. The grammar may be specified as LISP rules or as an already constructed {EST_SCFG}.

This produces a single best parse. It treats the grammar as strictly context free in that the probability of a nonterminal over vertex n to m, is the sum of all the possible analyses of that sub-tree. Only the best analysis is kept for the resulting parse tree.

Author

Alan W Black (awb@c.nosp@m.str..nosp@m.ed.ac.nosp@m..uk): October 1997

Definition at line 100 of file EST_SCFG_Chart.h.

Member Function Documentation

void EST_SCFG_Chart::setup_wfst	(	EST_Relation *	s,
		const EST_String &	name = "name"
	)

Initialize for parsing from relation using { name} feature setting up the "Well Formed Substring Table"

Definition at line 137 of file EST_SCFG_Chart.cc.

void EST_SCFG_Chart::setup_wfst	(	EST_Item *	s,
		EST_Item *	e,
		const EST_String &	name = "name"
	)

Initialize for parsing from s to e using { name} feature setting up the "Well Formed Substring Table"

Definition at line 144 of file EST_SCFG_Chart.cc.

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The documentation for this class was generated from the following files:

• include/EST_SCFG_Chart.h
• grammar/scfg/EST_SCFG_Chart.cc