grammar::fa::dacceptor -
Create and use deterministic acceptors
package require Tcl 8.4
package require snit
package require struct::set
package require grammar::fa::dacceptor ? 0.1.1 ?
::grammar::fa::dacceptor daName fa ? -any any ?
daName option ? arg arg ... ?
daName destroy
daName accept? symbols
This package provides a class for acceptors constructed from
deterministic finite automatons (DFA). Acceptors are objects
which can be given a string of symbols and tell if the DFA they are
constructed from would accept that string.
For the actual creation of the DFAs the acceptors are based on we have
the packages grammar::fa and grammar::fa::op.
The package exports the API described here.
-
::grammar::fa::dacceptor daName fa ? -any any ?
-
Creates a new deterministic acceptor with an associated global Tcl command
whose name is daName. This command may be used to invoke various
operations on the acceptor. It has the following general form:
-
daName option ? arg arg ... ?
-
Option and the args determine the exact behavior of the
command. See section ACCEPTOR METHODS for more explanations.
The acceptor will be based on the deterministic finite automaton
stored in the object fa. It will keep a copy of the relevant
data of the FA in its own storage, in a form easy to use for its
purposes. This also means that changes made to the fa after the
construction of the acceptor will not influence the acceptor.
If any has been specified, then the acceptor will convert all
symbols in the input which are unknown to the base FA to that symbol
before proceeding with the processing.
All acceptors provide the following methods for their manipulation:
-
daName destroy
-
Destroys the automaton, including its storage space and associated
command.
-
daName accept? symbols
-
Takes the list of symbols and checks if the FA the acceptor is
based on would accept it. The result is a boolean value. True
is returned if the symbols are accepted, and False
otherwise. Note that bogus symbols in the input are either translated
to the any symbol (if specified), or cause the acceptance test
to simply fail. No errors will be thrown. The method will process only
just that prefix of the input which is enough to fully determine
(non-)acceptance.
This document, and the package it describes, will undoubtedly contain
bugs and other problems.
Please report such in the category
grammar_fa of the
http://sourceforge.net/tracker/?group_id=12883.
Please also report any ideas for enhancements you may have for either
package and/or documentation.
acceptor, acceptance, grammar, automaton, finite automaton, state, regular expression, regular grammar, regular languages, parsing, transducer