1 ! Copyright (C) 2008 Doug Coleman.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: accessors arrays assocs fry hashtables kernel sequences
5 IN: regexp.transition-tables
7 TUPLE: transition from to obj ;
8 TUPLE: literal-transition < transition ;
9 TUPLE: class-transition < transition ;
10 TUPLE: default-transition < transition ;
15 : make-transition ( from to obj class -- obj )
21 : <literal-transition> ( from to obj -- transition )
22 literal-transition make-transition ;
24 : <class-transition> ( from to obj -- transition )
25 class-transition make-transition ;
27 : <default-transition> ( from to -- transition )
28 t default-transition make-transition ;
30 TUPLE: transition-table transitions start-state final-states ;
32 : <transition-table> ( -- transition-table )
34 H{ } clone >>transitions
35 H{ } clone >>final-states ;
37 : maybe-initialize-key ( key hashtable -- )
38 2dup key? [ 2drop ] [ H{ } clone -rot set-at ] if ;
40 : set-transition ( transition hash -- )
41 #! set the state as a key
42 2dup [ to>> ] dip maybe-initialize-key
43 [ [ to>> ] [ obj>> ] [ from>> ] tri ] dip
44 2dup at* [ 2nip insert-at ]
45 [ drop [ H{ } clone [ insert-at ] keep ] 2dip set-at ] if ;
47 : add-transition ( transition transition-table -- )
48 transitions>> set-transition ;