NAME

       grammar::fa::dacceptor - Create and use deterministic acceptors

SYNOPSIS

       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

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DESCRIPTION

       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.

API

       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.

ACCEPTOR METHODS

       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.

EXAMPLES

BUGS, IDEAS, FEEDBACK

       This  document,  and  the package it describes, will undoubtedly contain bugs and other problems.  Please
       report     such     in     the     category     grammar_fa     of     the     Tcllib     SF      Trackers
       [http://sourceforge.net/tracker/?group_id=12883].   Please also report any ideas for enhancements you may
       have for either package and/or documentation.

KEYWORDS

       acceptance, acceptor, automaton, finite automaton, grammar, parsing, regular expression, regular grammar,
       regular languages, state, transducer

CATEGORY

       Grammars and finite automata

COPYRIGHT

       Copyright (c) 2004 Andreas Kupries <andreas_kupries@users.sourceforge.net>