1 ! Copyright (C) 2007, 2008 Slava Pestov, Eduardo Cavazos.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: accessors arrays assocs classes classes.tuple combinators
4 fry.private hashtables kernel locals.backend locals.errors
5 locals.types macros.expander make math memoize.private
6 quotations sequences sets words ;
12 ! Step 1: rewrite [| into :> forms, turn
13 ! literals with locals in them into code which constructs
14 ! the literal after pushing locals on the stack
16 GENERIC: rewrite-sugar* ( obj -- )
18 : (rewrite-sugar) ( form -- form' )
19 [ rewrite-sugar* ] [ ] make ;
21 GENERIC: quotation-rewrite ( form -- form' )
23 M: callable quotation-rewrite [ [ rewrite-sugar* ] each ] [ ] make ;
25 : var-defs ( vars -- defs )
26 [ [ ] ] [ <multi-def> 1quotation ] if-empty ;
28 M: lambda quotation-rewrite
29 [ body>> ] [ vars>> var-defs ] bi prepend quotation-rewrite ;
31 M: callable rewrite-sugar* quotation-rewrite , ;
33 M: lambda rewrite-sugar* quotation-rewrite , ;
35 GENERIC: rewrite-literal? ( obj -- ? )
37 M: special rewrite-literal? drop t ;
39 M: sequence rewrite-literal? [ rewrite-literal? ] any? ;
41 M: wrapper rewrite-literal? wrapped>> rewrite-literal? ;
43 M: hashtable rewrite-literal? >alist rewrite-literal? ;
45 M: tuple rewrite-literal? tuple>array rewrite-literal? ;
47 M: object rewrite-literal? drop f ;
49 GENERIC: rewrite-element ( obj -- )
51 : rewrite-elements ( seq -- )
52 [ rewrite-element ] each ;
54 : rewrite-sequence ( seq -- )
55 [ rewrite-elements ] [ length ] [ 0 head ] tri
56 [ [nsequence] % ] [ [ like ] curry % ] bi ;
58 M: sequence rewrite-element
59 dup rewrite-literal? [ rewrite-sequence ] [ , ] if ;
61 M: hashtable rewrite-element
62 dup rewrite-literal? [ >alist rewrite-sequence \ >hashtable , ] [ , ] if ;
64 M: tuple rewrite-element
65 dup rewrite-literal? [
66 [ tuple-slots rewrite-elements ] [ class-of ] bi '[ _ boa ] %
69 M: quotation rewrite-element rewrite-sugar* ;
71 M: lambda rewrite-element rewrite-sugar* ;
73 M: let rewrite-element let-form-in-literal-error ;
75 M: local rewrite-element , ;
77 M: local-reader rewrite-element , ;
79 M: local-writer rewrite-element local-writer-in-literal-error ;
81 M: word rewrite-element <wrapper> , ;
83 : rewrite-wrapper ( wrapper -- )
84 dup rewrite-literal? [ wrapped>> rewrite-element ] [ , ] if ;
86 M: wrapper rewrite-element
87 rewrite-wrapper \ <wrapper> , ;
89 M: object rewrite-element , ;
91 M: sequence rewrite-sugar* rewrite-element ;
93 M: tuple rewrite-sugar* rewrite-element ;
95 M: multi-def rewrite-sugar* , ;
97 M: hashtable rewrite-sugar* rewrite-element ;
99 M: wrapper rewrite-sugar*
102 M: word rewrite-sugar*
103 dup { load-locals get-local drop-locals } member-eq?
104 [ >r/r>-in-lambda-error ] [ call-next-method ] if ;
106 M: object rewrite-sugar* , ;
108 M: let rewrite-sugar*
109 body>> quotation-rewrite % ;
111 ! Step 2: identify free variables and make them into explicit
112 ! parameters of lambdas which are curried on
114 GENERIC: rewrite-closures* ( obj -- )
116 : (rewrite-closures) ( form -- form' )
117 [ [ rewrite-closures* ] each ] [ ] make ;
119 : rewrite-closures ( form -- form' )
120 expand-macros (rewrite-sugar) (rewrite-closures) point-free ;
122 GENERIC: defs-vars* ( seq form -- seq' )
124 : defs-vars ( form -- vars ) { } [ defs-vars* ] reduce members ;
126 M: multi-def defs-vars* locals>> [ unquote suffix ] each ;
128 M: quotation defs-vars* [ defs-vars* ] each ;
130 M: object defs-vars* drop ;
132 GENERIC: uses-vars* ( seq form -- seq' )
134 : uses-vars ( form -- vars ) { } [ uses-vars* ] reduce members ;
136 M: local-writer uses-vars* "local-reader" word-prop suffix ;
138 M: lexical uses-vars* suffix ;
140 M: quote uses-vars* local>> uses-vars* ;
142 M: object uses-vars* drop ;
144 M: quotation uses-vars* [ uses-vars* ] each ;
146 : free-vars ( form -- seq )
147 [ uses-vars ] [ defs-vars ] bi diff ;
149 M: callable rewrite-closures*
150 ! Turn free variables into bound variables, curry them
152 dup free-vars [ <quote> ] map
154 [ var-defs prepend (rewrite-closures) point-free , ]
155 [ length \ curry <repetition> % ]
158 M: object rewrite-closures* , ;
160 ! Step 3: rewrite locals usage within a single quotation into
161 ! retain stack manipulation
163 : local-index ( args obj -- n )
164 2dup '[ unquote _ eq? ] find drop
165 [ 2nip ] [ bad-local ] if* ;
167 : read-local-quot ( args obj -- quot )
168 local-index neg [ get-local ] curry ;
170 GENERIC: localize ( args obj -- args quot )
172 M: local localize dupd read-local-quot ;
174 M: quote localize dupd local>> read-local-quot ;
176 M: local-reader localize dupd read-local-quot [ local-value ] append ;
178 M: local-writer localize
179 dupd "local-reader" word-prop
180 read-local-quot [ set-local-value ] append ;
182 M: multi-def localize
185 [ [ [ local-reader? ] dip '[ [ 1array ] _ [ndip] ] [ [ ] ] if ] map-index concat ]
188 { [ dup 1 > ] [ [ load-locals ] curry ] }
189 { [ dup 1 = ] [ drop [ load-local ] ] }
194 M: object localize 1quotation ;
196 : drop-locals-quot ( args -- )
197 [ length , [ drop-locals ] % ] unless-empty ;
199 : point-free ( quot -- newquot )
200 [ { } swap [ localize % ] each drop-locals-quot ] [ ] make ;