Check stack effect of actions in ebnf. Do implicit drop if needed

db4
Chris Double 2008-06-17 15:25:47 +12:00
parent 1b8943a8e0
commit f1219c906a
1 changed files with 10 additions and 3 deletions

View File

@ -2,8 +2,8 @@
! See http://factorcode.org/license.txt for BSD license.
USING: kernel compiler.units parser words arrays strings math.parser sequences
quotations vectors namespaces math assocs continuations peg
peg.parsers unicode.categories multiline combinators.lib
splitting accessors effects sequences.deep peg.search ;
peg.parsers unicode.categories multiline combinators combinators.lib
splitting accessors effects sequences.deep peg.search inference ;
IN: peg.ebnf
TUPLE: ebnf-non-terminal symbol ;
@ -340,9 +340,16 @@ M: ebnf-var build-locals ( code ast -- )
M: object build-locals ( code ast -- )
drop ;
: check-action-effect ( quot -- quot )
dup infer {
{ [ dup (( a -- b )) effect<= ] [ drop ] }
{ [ dup (( -- b )) effect<= ] [ drop [ drop ] prepose ] }
[ "Bad effect: " swap effect>string append throw ]
} cond ;
M: ebnf-action (transform) ( ast -- parser )
[ parser>> (transform) ] [ code>> ] [ parser>> ] tri build-locals
string-lines parse-lines action ;
string-lines parse-lines check-action-effect action ;
M: ebnf-semantic (transform) ( ast -- parser )
[ parser>> (transform) ] [ code>> ] [ parser>> ] tri build-locals