! Copyright (C) 2007, 2008 Chris Double.
! See http://factorcode.org/license.txt for BSD license.
-USING: kernel sequences strings fry namespaces make math assocs
-io vectors arrays math.parser math.order combinators classes
-sets unicode.categories compiler.units parser effects.parser
-words quotations memoize accessors locals splitting
-combinators.short-circuit generalizations ;
-FROM: namespaces => set ;
+
+USING: accessors arrays assocs classes combinators
+combinators.short-circuit compiler.units effects.parser fry
+kernel make math math.order namespaces quotations sequences
+sets splitting unicode vectors vocabs.loader words ;
+
IN: peg
TUPLE: parse-result remaining ast ;
} cond ;
: merge-errors ( -- )
- error-stack get dup length 1 > [
- dup pop over pop swap (merge-errors) swap push
+ error-stack get dup length 1 > [
+ [ pop ] [ pop swap (merge-errors) ] [ ] tri push
] [
drop
] if ;
SYMBOL: ignore
+: ignore? ( obj -- ? )
+ ignore = ;
+
: packrat ( id -- cache )
- #! The packrat cache is a mapping of parser-id->cache.
- #! For each parser it maps to a cache holding a mapping
- #! of position->result. The packrat cache therefore keeps
- #! track of all parses that have occurred at each position
- #! of the input string and the results obtained from that
- #! parser.
+ ! The packrat cache is a mapping of parser-id->cache.
+ ! For each parser it maps to a cache holding a mapping
+ ! of position->result. The packrat cache therefore keeps
+ ! track of all parses that have occurred at each position
+ ! of the input string and the results obtained from that
+ ! parser.
\ packrat get [ drop H{ } clone ] cache ;
SYMBOL: pos
SYMBOL: lrstack
: heads ( -- cache )
- #! A mapping from position->peg-head. It maps a
- #! position in the input string being parsed to
- #! the head of the left recursion which is currently
- #! being grown. It is 'f' at any position where
- #! left recursion growth is not underway.
+ ! A mapping from position->peg-head. It maps a
+ ! position in the input string being parsed to
+ ! the head of the left recursion which is currently
+ ! being grown. It is 'f' at any position where
+ ! left recursion growth is not underway.
\ heads get ;
: failed? ( obj -- ? )
fail = ;
: peg-cache ( -- cache )
- #! Holds a hashtable mapping a peg tuple to
- #! the parser tuple for that peg. The parser tuple
- #! holds a unique id and the compiled form of that peg.
+ ! Holds a hashtable mapping a peg tuple to
+ ! the parser tuple for that peg. The parser tuple
+ ! holds a unique id and the compiled form of that peg.
\ peg-cache get-global [
H{ } clone dup \ peg-cache set-global
] unless* ;
reset-pegs
-#! An entry in the table of memoized parse results
-#! ast = an AST produced from the parse
-#! or the symbol 'fail'
-#! or a left-recursion object
-#! pos = the position in the input string of this entry
+! An entry in the table of memoized parse results
+! ast = an AST produced from the parse
+! or the symbol 'fail'
+! or a left-recursion object
+! pos = the position in the input string of this entry
TUPLE: memo-entry ans pos ;
TUPLE: left-recursion seed rule-id head next ;
TUPLE: peg-head rule-id involved-set eval-set ;
: rule-id ( word -- id )
- #! A rule is the parser compiled down to a word. It has
- #! a "peg-id" property containing the id of the original parser.
+ ! A rule is the parser compiled down to a word. It has
+ ! a "peg-id" property containing the id of the original parser.
"peg-id" word-prop ;
: input-slice ( -- slice )
- #! Return a slice of the input from the current parse position
+ ! Return a slice of the input from the current parse position
input get pos get tail-slice ;
: input-from ( input -- n )
- #! Return the index from the original string that the
- #! input slice is based on.
+ ! Return the index from the original string that the
+ ! input slice is based on.
dup slice? [ from>> ] [ drop 0 ] if ;
: process-rule-result ( p result -- result )
[
- nip [ ast>> ] [ remaining>> ] bi input-from pos set
+ nip [ ast>> ] [ remaining>> ] bi input-from pos namespaces:set
] [
- pos set fail
+ pos namespaces:set fail
] if* ;
: eval-rule ( rule -- ast )
- #! Evaluate a rule, return an ast resulting from it.
- #! Return fail if the rule failed. The rule has
- #! stack effect ( -- parse-result )
+ ! Evaluate a rule, return an ast resulting from it.
+ ! Return fail if the rule failed. The rule has
+ ! stack effect ( -- parse-result )
pos get swap execute( -- parse-result ) process-rule-result ; inline
: memo ( pos id -- memo-entry )
- #! Return the result from the memo cache.
+ ! Return the result from the memo cache.
packrat at ;
: set-memo ( memo-entry pos id -- )
- #! Store an entry in the cache
+ ! Store an entry in the cache
packrat set-at ;
: update-m ( ast m -- )
swap >>ans pos get >>pos drop ;
: stop-growth? ( ast m -- ? )
- [ failed? pos get ] dip
- pos>> <= or ;
+ [ failed? pos get ] dip pos>> <= or ;
: setup-growth ( h p -- )
- pos set dup involved-set>> clone >>eval-set drop ;
+ pos namespaces:set dup involved-set>> clone >>eval-set drop ;
: (grow-lr) ( h p r: ( -- result ) m -- )
[ [ setup-growth ] 2keep ] 2dip
[ dup eval-rule ] dip swap
dup pick stop-growth? [
- 5 ndrop
+ 5drop
] [
over update-m
(grow-lr)
[ [ heads set-at ] 2keep ] 2dip
pick over [ (grow-lr) ] 2dip
swap heads delete-at
- dup pos>> pos set ans>>
+ dup pos>> pos namespaces:set ans>>
; inline
:: (setup-lr) ( l s -- )
:: apply-non-memo-rule ( r p -- ast )
fail r rule-id f lrstack get left-recursion boa :> lr
- lr lrstack set lr p memo-entry boa dup p r rule-id set-memo :> m
+ lr lrstack namespaces:set lr p memo-entry boa dup p r rule-id set-memo :> m
r eval-rule :> ans
- lrstack get next>> lrstack set
+ lrstack get next>> lrstack namespaces:set
pos get m pos<<
lr head>> [
m ans>> left-recursion? [
] if ; inline
: apply-memo-rule ( r m -- ast )
- [ ans>> ] [ pos>> ] bi pos set
+ [ ans>> ] [ pos>> ] bi pos namespaces:set
dup left-recursion? [
[ setup-lr ] keep seed>>
] [
] if* ; inline
: with-packrat ( input quot -- result )
- #! Run the quotation with a packrat cache active.
+ ! Run the quotation with a packrat cache active.
[
swap input ,,
0 pos ,,
: execute-parser ( word -- result )
pos get apply-rule process-parser-result ;
-: preset-parser-word ( parser -- parser word )
- gensym [ >>compiled ] keep ;
+: preset-parser-word ( parser -- word parser )
+ gensym tuck >>compiled ;
-: define-parser-word ( parser word -- )
- #! Return the body of the word that is the compiled version
- #! of the parser.
- 2dup swap peg>> (compile) ( -- result ) define-declared
- swap id>> "peg-id" set-word-prop ;
+: define-parser-word ( word parser -- )
+ ! Return the body of the word that is the compiled version
+ ! of the parser.
+ [ peg>> (compile) ( -- result ) define-declared ]
+ [ id>> "peg-id" set-word-prop ] 2bi ;
: compile-parser ( parser -- word )
- #! Look to see if the given parser has been compiled.
- #! If not, compile it to a temporary word, cache it,
- #! and return it. Otherwise return the existing one.
- #! Circular parsers are supported by getting the word
- #! name and storing it in the cache, before compiling,
- #! so it is picked up when re-entered.
+ ! Look to see if the given parser has been compiled.
+ ! If not, compile it to a temporary word, cache it,
+ ! and return it. Otherwise return the existing one.
+ ! Circular parsers are supported by getting the word
+ ! name and storing it in the cache, before compiling,
+ ! so it is picked up when re-entered.
dup compiled>> [
nip
] [
- preset-parser-word [ define-parser-word ] keep
+ preset-parser-word dupd define-parser-word
] if* ;
: compile-parser-quot ( parser -- quot )
- compile-parser [ execute-parser ] curry ;
+ compile-parser '[ _ execute-parser ] ;
+
+: compile-parsers-quots ( parsers -- quots )
+ [ compile-parser-quot ] map dup rest-slice
+ [ '[ @ merge-errors ] ] map! drop ;
SYMBOL: delayed
: fixup-delayed ( -- )
- #! Work through all delayed parsers and recompile their
- #! words to have the correct bodies.
+ ! Work through all delayed parsers and recompile their
+ ! words to have the correct bodies.
delayed get [
call( -- parser ) compile-parser-quot ( -- result ) define-declared
] assoc-each ;
: compile ( parser -- word )
[
H{ } clone delayed [
- compile-parser-quot ( -- result ) define-temp fixup-delayed
+ compile-parser fixup-delayed
] with-variable
] with-compilation-unit ;
: compiled-parse ( state word -- result )
- swap [ execute( -- result ) [ error-stack get first throw ] unless* ] with-packrat ;
+ swap [
+ execute-parser
+ [ error-stack get ?first [ throw ]
+ [ pos get input get f <parse-error> throw ] if* ] unless*
+ ] with-packrat ;
: (parse) ( input parser -- result )
- dup word? [ compile ] unless compiled-parse ;
+ compile compiled-parse ;
: parse ( input parser -- ast )
(parse) ast>> ;
<PRIVATE
-SYMBOL: id
-
: next-id ( -- n )
- #! Return the next unique id for a parser
- id get-global [
- dup 1 + id set-global
- ] [
- 1 id set-global 0
- ] if* ;
+ ! Return the next unique id for a parser
+ \ next-id counter ;
: wrap-peg ( peg -- parser )
- #! Wrap a parser tuple around the peg object.
- #! Look for an existing parser tuple for that
- #! peg object.
- peg-cache [
- f next-id parser boa
- ] cache ;
+ ! Wrap a parser tuple around the peg object.
+ ! Look for an existing parser tuple for that
+ ! peg object.
+ peg-cache [ f next-id parser boa ] cache ;
TUPLE: token-parser symbol ;
: parse-token ( input string -- result )
- #! Parse the string, returning a parse result
+ ! Parse the string, returning a parse result
[ ?head-slice ] keep swap [
- <parse-result> f f f add-error
+ <parse-result>
] [
[ seq>> pos get swap ] dip "'" "'" surround 1vector add-error f
] if ;
-M: token-parser (compile) ( peg -- quot )
+M: token-parser (compile)
symbol>> '[ input-slice _ parse-token ] ;
TUPLE: satisfy-parser quot ;
-: parse-satisfy ( input quot -- result )
- swap dup empty? [
- 2drop f
- ] [
- unclip-slice rot dupd call [
+:: parse-satisfy ( input quot -- result/f )
+ input [ f ] [
+ unclip-slice dup quot call [
<parse-result>
] [
2drop f
] if
- ] if ; inline
-
+ ] if-empty ; inline
-M: satisfy-parser (compile) ( peg -- quot )
+M: satisfy-parser (compile)
quot>> '[ input-slice _ parse-satisfy ] ;
TUPLE: range-parser min max ;
-: parse-range ( input min max -- result )
- pick empty? [
- 3drop f
- ] [
- [ dup first ] 2dip between? [
+:: parse-range ( input min max -- result/f )
+ input [ f ] [
+ dup first min max between? [
unclip-slice <parse-result>
] [
drop f
] if
- ] if ;
+ ] if-empty ;
-M: range-parser (compile) ( peg -- quot )
+M: range-parser (compile)
[ min>> ] [ max>> ] bi '[ input-slice _ _ parse-range ] ;
TUPLE: seq-parser parsers ;
-: ignore? ( ast -- bool )
- ignore = ;
-
: calc-seq-result ( prev-result current-result -- next-result )
[
- [ remaining>> swap remaining<< ] 2keep
- ast>> dup ignore? [
- drop
- ] [
- swap [ ast>> push ] keep
- ] if
+ [ remaining>> >>remaining ] [ ast>> ] bi
+ dup ignore? [ drop ] [ over ast>> push ] if
] [
drop f
] if* ;
: parse-seq-element ( result quot -- result )
- over [
- call calc-seq-result
- ] [
- 2drop f
- ] if ; inline
+ '[ @ calc-seq-result ] [ f ] if* ; inline
-M: seq-parser (compile) ( peg -- quot )
- [
- [ input-slice V{ } clone <parse-result> ] %
- [
- parsers>> unclip compile-parser-quot [ parse-seq-element ] curry ,
- [ compile-parser-quot [ merge-errors ] compose [ parse-seq-element ] curry , ] each
- ] { } make , \ 1&& ,
- ] [ ] make ;
+M: seq-parser (compile)
+ parsers>> compile-parsers-quots
+ [ '[ _ parse-seq-element ] ] map
+ '[ input-slice V{ } clone <parse-result> _ 1&& ] ;
TUPLE: choice-parser parsers ;
-M: choice-parser (compile) ( peg -- quot )
- [
- [
- parsers>> [ compile-parser-quot ] map
- unclip , [ [ merge-errors ] compose , ] each
- ] { } make , \ 0|| ,
- ] [ ] make ;
+M: choice-parser (compile)
+ parsers>> compile-parsers-quots '[ _ 0|| ] ;
-TUPLE: repeat0-parser p1 ;
+TUPLE: repeat0-parser parser ;
-: (repeat) ( quot: ( -- result ) result -- result )
+: (repeat) ( quot: ( -- result/f ) result -- result )
over call [
- [ remaining>> swap remaining<< ] 2keep
- ast>> swap [ ast>> push ] keep
- (repeat)
+ [ remaining>> >>remaining ] [ ast>> ] bi
+ over ast>> push (repeat)
] [
nip
] if* ; inline recursive
-M: repeat0-parser (compile) ( peg -- quot )
- p1>> compile-parser-quot '[
+M: repeat0-parser (compile)
+ parser>> compile-parser-quot '[
input-slice V{ } clone <parse-result> _ swap (repeat)
] ;
-TUPLE: repeat1-parser p1 ;
+TUPLE: repeat1-parser parser ;
: repeat1-empty-check ( result -- result )
- [
- dup ast>> empty? [ drop f ] when
- ] [
- f
- ] if* ;
+ [ dup ast>> empty? [ drop f ] when ] [ f ] if* ;
-M: repeat1-parser (compile) ( peg -- quot )
- p1>> compile-parser-quot '[
- input-slice V{ } clone <parse-result> _ swap (repeat) repeat1-empty-check
+M: repeat1-parser (compile)
+ parser>> compile-parser-quot '[
+ input-slice V{ } clone <parse-result> _ swap (repeat)
+ repeat1-empty-check
] ;
-TUPLE: optional-parser p1 ;
+TUPLE: optional-parser parser ;
: check-optional ( result -- result )
-
[ input-slice f <parse-result> ] unless* ;
+ [ input-slice f <parse-result> ] unless* ;
-M: optional-parser (compile) ( peg -- quot )
- p1>> compile-parser-quot '[ @ check-optional ] ;
+M: optional-parser (compile)
+ parser>> compile-parser-quot '[ @ check-optional ] ;
-TUPLE: semantic-parser p1 quot ;
+TUPLE: semantic-parser parser quot ;
: check-semantic ( result quot -- result )
- over [
- over ast>> swap call [ drop f ] unless
- ] [
- drop
- ] if ; inline
+ dupd '[ dup ast>> @ [ drop f ] unless ] when ; inline
-M: semantic-parser (compile) ( peg -- quot )
- [ p1>> compile-parser-quot ] [ quot>> ] bi
+M: semantic-parser (compile)
+ [ parser>> compile-parser-quot ] [ quot>> ] bi
'[ @ _ check-semantic ] ;
-TUPLE: ensure-parser p1 ;
+TUPLE: ensure-parser parser ;
: check-ensure ( old-input result -- result )
[ ignore <parse-result> ] [ drop f ] if ;
-M: ensure-parser (compile) ( peg -- quot )
- p1>> compile-parser-quot '[ input-slice @ check-ensure ] ;
+M: ensure-parser (compile)
+ parser>> compile-parser-quot '[ input-slice @ check-ensure ] ;
-TUPLE: ensure-not-parser p1 ;
+TUPLE: ensure-not-parser parser ;
: check-ensure-not ( old-input result -- result )
[ drop f ] [ ignore <parse-result> ] if ;
-M: ensure-not-parser (compile) ( peg -- quot )
- p1>> compile-parser-quot '[ input-slice @ check-ensure-not ] ;
+M: ensure-not-parser (compile)
+ parser>> compile-parser-quot '[ input-slice @ check-ensure-not ] ;
-TUPLE: action-parser p1 quot ;
+TUPLE: action-parser parser quot ;
: check-action ( result quot -- result )
- over [
- over ast>> swap call( ast -- ast ) >>ast
- ] [
- drop
- ] if ;
+ dupd '[ [ _ call( ast -- ast ) ] change-ast ] when ;
-M: action-parser (compile) ( peg -- quot )
- [ p1>> compile-parser-quot ] [ quot>> ] bi '[ @ _ check-action ] ;
+M: action-parser (compile)
+ [ parser>> compile-parser-quot ] [ quot>> ] bi
+ '[ @ _ check-action ] ;
-TUPLE: sp-parser p1 ;
+TUPLE: sp-parser parser ;
-M: sp-parser (compile) ( peg -- quot )
- p1>> compile-parser-quot '[
- input-slice [ blank? ] trim-head-slice input-from pos set @
+M: sp-parser (compile)
+ parser>> compile-parser-quot '[
+ input-slice [ blank? ] trim-head-slice input-from pos namespaces:set @
] ;
TUPLE: delay-parser quot ;
-M: delay-parser (compile) ( peg -- quot )
- #! For efficiency we memoize the quotation.
- #! This way it is run only once and the
- #! parser constructed once at run time.
+M: delay-parser (compile)
+ ! For efficiency we memoize the quotation.
+ ! This way it is run only once and the
+ ! parser constructed once at run time.
quot>> gensym [ delayed get set-at ] keep 1quotation ;
TUPLE: box-parser quot ;
-M: box-parser (compile) ( peg -- quot )
- #! Calls the quotation at compile time
- #! to produce the parser to be compiled.
- #! This differs from 'delay' which calls
- #! it at run time.
+M: box-parser (compile)
+ ! Calls the quotation at compile time
+ ! to produce the parser to be compiled.
+ ! This differs from 'delay' which calls
+ ! it at run time.
quot>> call( -- parser ) compile-parser-quot ;
PRIVATE>
: 4seq ( parser1 parser2 parser3 parser4 -- parser )
4array seq ;
-: seq* ( quot -- paser )
+: seq* ( quot -- parser )
{ } make seq ; inline
: choice ( seq -- parser )
: 4choice ( parser1 parser2 parser3 parser4 -- parser )
4array choice ;
-: choice* ( quot -- paser )
+: choice* ( quot -- parser )
{ } make choice ; inline
: repeat0 ( parser -- parser )
delay-parser boa wrap-peg ;
: box ( quot -- parser )
- #! because a box has its quotation run at compile time
- #! it must always have a new parser wrapper created,
- #! not a cached one. This is because the same box,
- #! compiled twice can have a different compiled word
- #! due to running at compile time.
- #! Why the [ ] action at the end? Box parsers don't get
- #! memoized during parsing due to all box parsers being
- #! unique. This breaks left recursion detection during the
- #! parse. The action adds an indirection with a parser type
- #! that gets memoized and fixes this. Need to rethink how
- #! to fix boxes so this isn't needed...
+ ! because a box has its quotation run at compile time
+ ! it must always have a new parser wrapper created,
+ ! not a cached one. This is because the same box,
+ ! compiled twice can have a different compiled word
+ ! due to running at compile time.
+ ! Why the [ ] action at the end? Box parsers don't get
+ ! memoized during parsing due to all box parsers being
+ ! unique. This breaks left recursion detection during the
+ ! parse. The action adds an indirection with a parser type
+ ! that gets memoized and fixes this. Need to rethink how
+ ! to fix boxes so this isn't needed...
box-parser boa f next-id parser boa [ ] action ;
ERROR: parse-failed input word ;
[let
(:) :> ( word def effect )
[
- [
- def call compile :> compiled-def
[
- dup compiled-def compiled-parse
- [ ast>> ] [ word parse-failed ] ?if
- ]
- word swap effect define-declared
- ] with-compilation-unit
+ def call compile :> compiled-def
+ word [
+ dup compiled-def compiled-parse
+ [ ast>> ] [ word parse-failed ] ?if
+ ] effect define-declared
+ ] with-compilation-unit
] append!
] ;
-USE: vocabs.loader
-
{ "debugger" "peg" } "peg.debugger" require-when
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