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grammar::dacceptor(n) 0.1 "Grammar operations and usage"
grammar::dacceptor - Create and use deterministic acceptors
TABLE OF
CONTENTS
SYNOPSIS
DESCRIPTION
API
ACCEPTOR
METHODS
EXAMPLES
KEYWORDS
COPYRIGHT
package require Tcl 8.4
package require snit
package require struct::set
package require grammar::dacceptor ?0.1?
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.
acceptance , acceptor , automaton , finite automaton , grammar , parsing , regular expression , regular grammar , regular languages , state , transducer
Copyright © 2004 Andreas Kupries
<andreas_kupries@users.sourceforge.net>