141 lines
		
	
	
		
			4.0 KiB
		
	
	
	
		
			Factor
		
	
	
			
		
		
	
	
			141 lines
		
	
	
		
			4.0 KiB
		
	
	
	
		
			Factor
		
	
	
| ! Copyright (C) 2005, 2006 Daniel Ehrenberg
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| ! See http://factorcode.org/license.txt for BSD license.
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| USING: io io.streams.string kernel math namespaces sequences
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| strings circular prettyprint debugger ascii ;
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| IN: state-parser
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| 
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| ! * Basic underlying words
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| ! Code stored in stdio
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| ! Spot is composite so it won't be lost in sub-scopes
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| TUPLE: spot char line column next ;
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| 
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| C: <spot> spot
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| 
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| : get-char ( -- char ) spot get spot-char ;
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| : set-char ( char -- ) spot get set-spot-char ;
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| : get-line ( -- line ) spot get spot-line ;
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| : set-line ( line -- ) spot get set-spot-line ;
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| : get-column ( -- column ) spot get spot-column ;
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| : set-column ( column -- ) spot get set-spot-column ;
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| : get-next ( -- char ) spot get spot-next ;
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| : set-next ( char -- ) spot get set-spot-next ;
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| 
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| ! * Errors
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| TUPLE: parsing-error line column ;
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| : <parsing-error> ( -- parsing-error )
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|     get-line get-column parsing-error boa ;
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| 
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| : construct-parsing-error ( ... slots class -- error )
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|     construct <parsing-error> over set-delegate ; inline
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| 
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| : parsing-error. ( parsing-error -- )
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|     "Parsing error" print
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|     "Line: " write dup parsing-error-line .
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|     "Column: " write parsing-error-column . ;
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| 
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| TUPLE: expected should-be was ;
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| : <expected> ( should-be was -- error )
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|     { set-expected-should-be set-expected-was }
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|     expected construct-parsing-error ;
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| M: expected error.
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|     dup parsing-error.
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|     "Token expected: " write dup expected-should-be print
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|     "Token present: " write expected-was print ;
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| 
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| TUPLE: unexpected-end ;
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| : <unexpected-end> ( -- unexpected-end )
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|     { } unexpected-end construct-parsing-error ;
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| M: unexpected-end error.
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|     parsing-error.
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|     "File unexpectedly ended." print ;
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| 
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| TUPLE: missing-close ;
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| : <missing-close> ( -- missing-close )
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|     { } missing-close construct-parsing-error ;
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| M: missing-close error.
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|     parsing-error.
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|     "Missing closing token." print ;
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| 
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| SYMBOL: prolog-data
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| 
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| ! * Basic utility words
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| 
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| : record ( char -- )
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|     CHAR: \n =
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|     [ 0 get-line 1+ set-line ] [ get-column 1+ ] if
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|     set-column ;
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| 
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| : (next) ( -- char ) ! this normalizes \r\n and \r
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|     get-next read1
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|     2dup swap CHAR: \r = [
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|         CHAR: \n =
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|         [ nip read1 ] [ nip CHAR: \n swap ] if
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|     ] [ drop ] if
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|     set-next dup set-char ;
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| 
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| : next ( -- )
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|     #! Increment spot.
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|     get-char [
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|         <unexpected-end> throw
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|     ] unless
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|     (next) record ;
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| 
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| : next* ( -- )
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|     get-char [ (next) record ] when ;
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| 
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| : skip-until ( quot -- )
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|     #! quot: ( -- ? )
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|     get-char [
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|         [ call ] keep swap [ drop ] [
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|             next skip-until
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|         ] if
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|     ] [ drop ] if ; inline
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| 
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| : take-until ( quot -- string )
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|     #! Take the substring of a string starting at spot
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|     #! from code until the quotation given is true and
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|     #! advance spot to after the substring.
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|     [ [
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|         dup slip swap dup [ get-char , ] unless
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|     ] skip-until ] "" make nip ; inline
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| 
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| : take-rest ( -- string )
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|     [ f ] take-until ;
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| 
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| : take-char ( ch -- string )
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|     [ dup get-char = ] take-until nip ;
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| 
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| : pass-blank ( -- )
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|     #! Advance code past any whitespace, including newlines
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|     [ get-char blank? not ] skip-until ;
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| 
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| : string-matches? ( string circular -- ? )
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|     get-char over push-circular
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|     sequence= ;
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| 
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| : take-string ( match -- string )
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|     dup length <circular-string>
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|     [ 2dup string-matches? ] take-until nip
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|     dup length rot length 1- - head
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|     get-char [ <missing-close> throw ] unless next ;
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| 
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| : expect ( ch -- )
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|     get-char 2dup = [ 2drop ] [
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|         >r 1string r> 1string <expected> throw
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|     ] if next ;
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| 
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| : expect-string ( string -- )
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|     dup [ drop get-char next ] map 2dup =
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|     [ 2drop ] [ <expected> throw ] if ;
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| 
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| : init-parser ( -- )
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|     0 1 0 f <spot> spot set
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|     read1 set-next next ;
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| 
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| : state-parse ( stream quot -- )
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|     ! with-stream implicitly creates a new scope which we use
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|     swap [ init-parser call ] with-stream ; inline
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| 
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| : string-parse ( input quot -- )
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|     >r <string-reader> r> state-parse ; inline
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