factor/library/syntax/parse-words.factor

153 lines
3.9 KiB
Factor

! Copyright (C) 2005 Slava Pestov.
! See http://factor.sf.net/license.txt for BSD license.
IN: parser
USING: errors kernel lists math namespaces sequences io
strings words ;
! The parser uses a number of variables:
! line - the line being parsed
! pos - position in the line
! use - list of vocabularies
! in - vocabulary for new words
!
! When a token is scanned, it is searched for in the 'use' list
! of vocabularies. If it is a parsing word, it is executed
! immediately. Otherwise it is appended to the parse tree.
SYMBOL: line-number
: use+ ( string -- ) "use" [ cons ] change ;
: parsing? ( word -- ? )
dup word? [ "parsing" word-prop ] [ drop f ] ifte ;
SYMBOL: file
: skip ( i seq quot -- n | quot: elt -- ? )
over >r find* drop dup -1 =
[ drop r> length ] [ r> drop ] ifte ; inline
: skip-blank ( -- )
"col" [ "line" get [ blank? not ] skip ] change ;
: skip-word ( n line -- n )
2dup nth CHAR: " = [ drop 1 + ] [ [ blank? ] skip ] ifte ;
: (scan) ( n line -- start end )
dupd 2dup length < [ skip-word ] [ drop ] ifte ;
: scan ( -- token )
skip-blank
"col" [ "line" get (scan) dup ] change
2dup = [ 2drop f ] [ "line" get subseq ] ifte ;
: save-location ( word -- )
#! Remember where this word was defined.
dup set-word
dup line-number get "line" set-word-prop
dup "col" get "col" set-word-prop
file get "file" set-word-prop ;
: create-in "in" get create dup save-location ;
: CREATE ( -- word ) scan create-in ;
! If this variable is on, the parser does not internalize words;
! it just appends strings to the parse tree as they are read.
SYMBOL: string-mode
global [ string-mode off ] bind
: scan-word ( -- obj )
scan dup [
dup ";" = not string-mode get and [
dup "use" get search [ ] [ string>number ] ?ifte
] unless
] when ;
! Used by parsing words
: ch-search ( ch -- index )
"col" get "line" get index* ;
: (until) ( index -- str )
"col" get swap dup 1 + "col" set "line" get subseq ;
: until ( ch -- str )
ch-search (until) ;
: (until-eol) ( -- index )
CHAR: \n ch-search dup -1 = [ drop "line" get length ] when ;
: until-eol ( -- str )
#! This is just a hack to get "eval" to work with multiline
#! strings from jEdit with EOL comments. Normally, input to
#! the parser is already line-tokenized.
(until-eol) (until) ;
: escape ( ch -- esc )
[
[[ CHAR: e CHAR: \e ]]
[[ CHAR: n CHAR: \n ]]
[[ CHAR: r CHAR: \r ]]
[[ CHAR: t CHAR: \t ]]
[[ CHAR: s CHAR: \s ]]
[[ CHAR: \s CHAR: \s ]]
[[ CHAR: 0 CHAR: \0 ]]
[[ CHAR: \\ CHAR: \\ ]]
[[ CHAR: \" CHAR: \" ]]
] assoc dup [ "Bad escape" throw ] unless ;
: next-escape ( n str -- ch n )
2dup nth CHAR: u = [
swap 1 + dup 4 + [ rot subseq hex> ] keep
] [
over 1 + >r nth escape r>
] ifte ;
: next-char ( n str -- ch n )
2dup nth CHAR: \\ = [
>r 1 + r> next-escape
] [
over 1 + >r nth r>
] ifte ;
: doc-comment-here? ( parsed -- ? )
not "in-definition" get and ;
: parsed-stack-effect ( parsed str -- parsed )
over doc-comment-here? [
word "stack-effect" word-prop [
drop
] [
word swap "stack-effect" set-word-prop
] ifte
] [
drop
] ifte ;
: documentation+ ( word str -- )
over "documentation" word-prop [
swap "\n" swap append3
] when*
"documentation" set-word-prop ;
: parsed-documentation ( parsed str -- parsed )
over doc-comment-here? [
word swap documentation+
] [
drop
] ifte ;
: (parse-string) ( n str -- n )
2dup nth CHAR: " = [
drop 1 +
] [
[ next-char swap , ] keep (parse-string)
] ifte ;
: parse-string ( -- str )
#! Read a string from the input stream, until it is
#! terminated by a ".
"col" [
[ "line" get (parse-string) ] make-string swap
] change ;