1 ! Copyright (C) 2008, 2009 Doug Coleman, Daniel Ehrenberg.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: peg.ebnf kernel math.parser sequences assocs arrays fry math
4 combinators regexp.classes strings splitting peg locals accessors
5 regexp.ast unicode.case ;
8 : allowed-char? ( ch -- ? )
9 ".()|[*+?$^" member? not ;
13 : ensure-number ( n -- n )
14 [ bad-number ] unless* ;
16 :: at-error ( key assoc quot: ( key -- replacement ) -- value )
17 key assoc at* [ drop key quot call ] unless ; inline
19 ERROR: bad-class name ;
21 : parse-unicode-class ( name -- class )
25 : unicode-class ( name -- class )
26 dup parse-unicode-class [ ] [ bad-class ] ?if ;
28 : name>class ( name -- class )
30 { "lower" letter-class }
31 { "upper" LETTER-class }
32 { "alpha" Letter-class }
33 { "ascii" ascii-class }
34 { "digit" digit-class }
35 { "alnum" alpha-class }
36 { "punct" punctuation-class }
37 { "graph" java-printable-class }
38 { "blank" non-newline-blank-class }
39 { "cntrl" control-character-class }
40 { "xdigit" hex-digit-class }
41 { "space" java-blank-class }
42 } [ unicode-class ] at-error ;
44 : lookup-escape ( char -- ast )
46 { CHAR: t [ CHAR: \t ] }
47 { CHAR: n [ CHAR: \n ] }
48 { CHAR: r [ CHAR: \r ] }
49 { CHAR: f [ HEX: c ] }
50 { CHAR: a [ HEX: 7 ] }
51 { CHAR: e [ HEX: 1b ] }
52 { CHAR: \\ [ CHAR: \\ ] }
54 { CHAR: w [ c-identifier-class <primitive-class> ] }
55 { CHAR: W [ c-identifier-class <primitive-class> <not-class> ] }
56 { CHAR: s [ java-blank-class <primitive-class> ] }
57 { CHAR: S [ java-blank-class <primitive-class> <not-class> ] }
58 { CHAR: d [ digit-class <primitive-class> ] }
59 { CHAR: D [ digit-class <primitive-class> <not-class> ] }
61 { CHAR: z [ end-of-input <tagged-epsilon> ] }
62 { CHAR: Z [ end-of-file <tagged-epsilon> ] }
63 { CHAR: A [ beginning-of-input <tagged-epsilon> ] }
64 { CHAR: b [ word-break <tagged-epsilon> ] }
65 { CHAR: B [ word-break <not-class> <tagged-epsilon> ] }
69 : options-assoc ( -- assoc )
71 { CHAR: i case-insensitive }
72 { CHAR: d unix-lines }
74 { CHAR: r reversed-regexp }
78 : ch>option ( ch -- singleton )
81 : option>ch ( option -- string )
82 options-assoc value-at ;
84 : parse-options ( on off -- options )
85 [ [ ch>option ] { } map-as ] bi@ <options> ;
87 : string>options ( string -- options )
88 "-" split1 parse-options ;
90 : options>string ( options -- string )
92 [ [ option>ch ] map ] bi@
93 [ "-" glue ] unless-empty
96 ! TODO: add syntax for various parenthized things,
97 ! add greedy and nongreedy forms of matching
98 ! (once it's all implemented)
102 CharacterInBracket = !("}") Character
104 QuotedCharacter = !("\\E") .
106 Escape = "p{" CharacterInBracket*:s "}" => [[ s name>class <primitive-class> ]]
107 | "P{" CharacterInBracket*:s "}" => [[ s name>class <primitive-class> <negation> ]]
108 | "Q" QuotedCharacter*:s "\\E" => [[ s <concatenation> ]]
109 | "u" Character:a Character:b Character:c Character:d
110 => [[ { a b c d } hex> ensure-number ]]
111 | "x" Character:a Character:b
112 => [[ { a b } hex> ensure-number ]]
113 | "0" Character:a Character:b Character:c
114 => [[ { a b c } oct> ensure-number ]]
115 | . => [[ lookup-escape ]]
117 EscapeSequence = "\\" Escape:e => [[ e ]]
119 Character = EscapeSequence
120 | "$" => [[ $ <tagged-epsilon> ]]
121 | "^" => [[ ^ <tagged-epsilon> ]]
122 | . ?[ allowed-char? ]?
124 AnyRangeCharacter = EscapeSequence | .
126 RangeCharacter = !("]") AnyRangeCharacter
128 Range = RangeCharacter:a "-" RangeCharacter:b => [[ a b <range-class> ]]
131 StartRange = AnyRangeCharacter:a "-" RangeCharacter:b => [[ a b <range-class> ]]
134 Ranges = StartRange:s Range*:r => [[ r s prefix ]]
136 CharClass = "^"?:n Ranges:e => [[ e n char-class ]]
140 Parenthized = "?:" Alternation:a => [[ a ]]
141 | "?" Options:on "-"? Options:off ":" Alternation:a
142 => [[ a on off parse-options <with-options> ]]
143 | "?#" [^)]* => [[ f ]]
144 | "?~" Alternation:a => [[ a <negation> ]]
145 | "?=" Alternation:a => [[ a <lookahead> <tagged-epsilon> ]]
146 | "?!" Alternation:a => [[ a <lookahead> <not-class> <tagged-epsilon> ]]
147 | "?<=" Alternation:a => [[ a <lookbehind> <tagged-epsilon> ]]
148 | "?<!" Alternation:a => [[ a <lookbehind> <not-class> <tagged-epsilon> ]]
151 Element = "(" Parenthized:p ")" => [[ p ]]
152 | "[" CharClass:r "]" => [[ r ]]
156 Number = (!(","|"}").)* => [[ string>number ensure-number ]]
158 Times = "," Number:n "}" => [[ 0 n <from-to> ]]
159 | Number:n ",}" => [[ n <at-least> ]]
160 | Number:n "}" => [[ n n <from-to> ]]
161 | "}" => [[ bad-number ]]
162 | Number:n "," Number:m "}" => [[ n m <from-to> ]]
164 Repeated = Element:e "{" Times:t => [[ e t <times> ]]
165 | Element:e "??" => [[ e <maybe> ]]
166 | Element:e "*?" => [[ e <star> ]]
167 | Element:e "+?" => [[ e <plus> ]]
168 | Element:e "?" => [[ e <maybe> ]]
169 | Element:e "*" => [[ e <star> ]]
170 | Element:e "+" => [[ e <plus> ]]
173 Concatenation = Repeated*:r => [[ r sift <concatenation> ]]
175 Alternation = Concatenation:c ("|" Concatenation)*:a
176 => [[ a empty? [ c ] [ a values c prefix <alternation> ] if ]]
180 Main = Alternation End