1 ! Copyright (C) 2008, 2010 Slava Pestov, Joe Groff.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: accessors arrays combinators continuations io kernel
4 kernel.private math math.parser namespaces sequences
5 sequences.private source-files.errors strings vectors ;
12 { line-length fixnum }
14 { parsing-words vector } ;
16 TUPLE: lexer-parsing-word word line line-text column ;
18 ERROR: not-a-lexer object ;
20 : check-lexer ( lexer -- lexer )
21 dup lexer? [ not-a-lexer ] unless ; inline
23 : next-line ( lexer -- )
25 dup [ line>> ] [ text>> ] bi ?nth "" or
26 [ >>line-text ] [ length >>line-length ] bi
31 : push-parsing-word ( word -- )
32 lexer get check-lexer [
33 [ line>> ] [ line-text>> ] [ column>> ] tri
34 lexer-parsing-word boa
35 ] [ parsing-words>> push ] bi ;
37 : pop-parsing-word ( -- )
38 lexer get check-lexer parsing-words>> pop* ;
40 : new-lexer ( text class -- lexer )
44 V{ } clone >>parsing-words
45 dup next-line ; inline
47 : <lexer> ( text -- lexer )
50 ERROR: unexpected want got ;
52 : forbid-tab ( c -- c )
53 [ CHAR: \t eq? [ "[space]" "[tab]" unexpected ] when ] keep ; inline
55 : skip ( i seq ? -- n )
57 [ swap forbid-tab CHAR: \s eq? xor ] curry find-from drop
60 : change-lexer-column ( lexer quot -- )
61 [ check-lexer [ column>> ] [ line-text>> ] bi ] prepose
62 keep column<< ; inline
64 GENERIC: skip-blank ( lexer -- )
67 [ t skip ] change-lexer-column ;
69 GENERIC: skip-word ( lexer -- )
73 : quote? ( column text -- ? )
74 { fixnum string } declare nth CHAR: " eq? ;
76 : shebang? ( column text -- ? )
77 { fixnum string } declare swap zero? [
79 dup first-unsafe CHAR: # =
80 [ second-unsafe CHAR: ! = ] [ drop f ] if
89 { [ 2dup quote? ] [ drop 1 + ] }
90 { [ 2dup shebang? ] [ drop 2 + ] }
93 ] change-lexer-column ;
95 : still-parsing? ( lexer -- ? )
96 check-lexer [ line>> ] [ text>> length ] bi <= ;
98 : still-parsing-line? ( lexer -- ? )
99 check-lexer [ column>> ] [ line-length>> ] bi < ;
101 : (parse-token) ( lexer -- str )
109 : parse-token ( lexer -- str/f )
112 dup still-parsing-line?
113 [ (parse-token) ] [ dup next-line parse-token ] if
116 : ?scan-token ( -- str/f ) lexer get parse-token ;
118 PREDICATE: unexpected-eof < unexpected got>> not ;
120 : throw-unexpected-eof ( word -- * ) f unexpected ;
122 : scan-token ( -- str )
123 ?scan-token [ "token" throw-unexpected-eof ] unless* ;
125 : expect ( token -- )
126 scan-token 2dup = [ 2drop ] [ unexpected ] if ;
128 : each-token ( ... end quot: ( ... token -- ... ) -- ... )
129 [ scan-token ] 2dip 2over =
130 [ 3drop ] [ [ nip call ] [ each-token ] 2bi ] if ; inline recursive
132 : map-tokens ( ... end quot: ( ... token -- ... elt ) -- ... seq )
133 collector [ each-token ] dip { } like ; inline
135 : parse-tokens ( end -- seq )
138 TUPLE: lexer-error line column line-text parsing-words error ;
140 M: lexer-error error-file error>> error-file ;
142 M: lexer-error error-line [ error>> error-line ] [ line>> ] bi or ;
144 : <lexer-error> ( msg -- error )
150 [ parsing-words>> clone ]
152 ] dip lexer-error boa ;
154 : simple-lexer-dump ( error -- )
155 [ line>> number>string ": " append ]
158 pick length + CHAR: \s <string>
159 [ write ] [ print ] [ write "^" print ] tri* ;
161 : (parsing-word-lexer-dump) ( error parsing-word -- )
164 over line>> number>string length
167 ] [ line-text>> print ] bi
170 : parsing-word-lexer-dump ( error parsing-word -- )
171 2dup [ line>> ] same?
172 [ drop simple-lexer-dump ]
173 [ (parsing-word-lexer-dump) ] if ;
175 : lexer-dump ( error -- )
177 [ simple-lexer-dump ]
178 [ last parsing-word-lexer-dump ] if-empty ;
180 : with-lexer ( lexer quot -- newquot )
181 [ [ <lexer-error> rethrow ] recover ] curry
182 [ lexer ] dip with-variable ; inline