factor/basis/json/reader/reader.factor

104 lines
2.7 KiB
Factor

! Copyright (C) 2008 Peter Burns, 2009 Philipp Winkler
! See http://factorcode.org/license.txt for BSD license.
USING: arrays assocs combinators io io.streams.string json
kernel math math.parser prettyprint
sequences strings vectors ;
IN: json.reader
<PRIVATE
: value ( char -- num char )
1string " \t\r\n,:}]" read-until
[
append
[ string>float ]
[ [ "eE." index ] any? [ >integer ] unless ] bi
] dip ;
DEFER: j-string
: convert-string ( str -- str )
read1
{
{ CHAR: b [ 8 ] }
{ CHAR: f [ 12 ] }
{ CHAR: n [ CHAR: \n ] }
{ CHAR: r [ CHAR: \r ] }
{ CHAR: t [ CHAR: \t ] }
{ CHAR: u [ 4 read hex> ] }
[ ]
} case
dup
[ 1string append j-string append ]
[ drop ] if ;
: j-string ( -- str )
"\\\"" read-until CHAR: \" =
[ convert-string ] unless ;
: second-last ( seq -- second-last )
[ length 2 - ] keep nth ; inline
: third-last ( seq -- third-last )
[ length 3 - ] keep nth ; inline
: last2 ( seq -- second-last last )
[ second-last ] [ last ] bi ; inline
: last3 ( seq -- third-last second-last last )
[ third-last ] [ last2 ] bi ; inline
: v-over-push ( vec -- vec' )
dup length 2 >=
[
dup
[ pop ]
[ last ] bi push
] when ;
: v-pick-push ( vec -- vec' )
dup length 3 >=
[
dup
[ pop ]
[ second-last ] bi push
] when ;
: (close-array) ( accum -- accum' )
dup last vector? [ v-over-push ] unless
dup pop >array over push ;
: (close-hash) ( accum -- accum' )
dup length 3 >= [ v-over-push ] when
dup dup [ pop ] dip pop swap
zip H{ } assoc-clone-like over push ;
: scan ( accum char -- accum )
! 2dup . . ! Great for debug...
[
{
{ CHAR: \" [ j-string over push ] }
{ CHAR: [ [ V{ } clone over push ] }
{ CHAR: , [ v-over-push ] }
{ CHAR: ] [ (close-array) ] }
{ CHAR: { [ 2 [ V{ } clone over push ] times ] }
{ CHAR: : [ v-pick-push ] }
{ CHAR: } [ (close-hash) ] }
{ CHAR: \u000020 [ ] }
{ CHAR: \t [ ] }
{ CHAR: \r [ ] }
{ CHAR: \n [ ] }
{ CHAR: t [ 3 read drop t over push ] }
{ CHAR: f [ 4 read drop f over push ] }
{ CHAR: n [ 3 read drop json-null over push ] }
[ value [ over push ] dip [ scan ] when* ]
} case
] when* ;
: (json-parser>) ( string -- object )
[ V{ } clone [ read1 dup ] [ scan ] while drop first ] with-string-reader ;
PRIVATE>
: json> ( string -- object )
(json-parser>) ;