( Timbre framework for parsing  Rob Chapman  July 30, 1996 )
\ This framework parses the input using two rule sets.
\ Parsing is kept going by maintaining something in the input queue.
\ The default behaviour is to parse the input and then echo it to the
\ output.
\ The parse rule echoes any blanks preceding words while the word rule
\ grabs the next word in the input stream and switches to the word rule set.
\ GET-WORD has been redefined to allow blanks after a word not to be lost.

RULE-SET parse              ( rules for parsing code )
RULE-SET words              ( defined words to look for )

: GET-WORD  ( -- s )  GET-WORD  INPUT 1 - C@ BL =  IF  -1 in +!  ENDIF ;

: TRANSLATOR-INIT  ( -- )  TRANSLATOR-INIT  parse RULES  | parse word | ;

parse RULES
{ parse }[ INPUT  BL SKIP  INPUT  SWAP -  FOR  BL EMIT  NEXT ]{ check input }
{ word  }[ GET-WORD inputq STUFF  words RULES ]

{ check input }[ INPUT C@ 0=  IF  { get input } ENDIF ]
{ get input   }[ INPUT-LINE   IF  CR  { parse }  ELSE  { input done }  ENDIF ]
{ input done  }[ inputq 0Q ]

{ output word }[ COUNT TYPE  ?STOP ]

words RULES
{ }[ inputq PULL  parse RULES ]{ output word  parse word }