From 479fa6a5b5a3ea5ebec18d4eba8ae30579531c60 Mon Sep 17 00:00:00 2001
From: Chris Double <chris@bethia.(none)>
Date: Wed, 18 Jun 2008 15:07:23 +1200
Subject: [PATCH] Add support for calling foreign peg.ebnf rules
---
extra/peg/ebnf/ebnf.factor | 43 +++++++++++++++++++++++++++++++++-----
1 file changed, 38 insertions(+), 5 deletions(-)
diff --git a/extra/peg/ebnf/ebnf.factor b/extra/peg/ebnf/ebnf.factor
index 335607b463..4828ace9af 100644
--- a/extra/peg/ebnf/ebnf.factor
+++ b/extra/peg/ebnf/ebnf.factor
@@ -1,14 +1,19 @@
! Copyright (C) 2007 Chris Double.
! See http://factorcode.org/license.txt for BSD license.
-USING: kernel compiler.units parser words arrays strings math.parser sequences
+USING: kernel compiler.units words arrays strings math.parser sequences
quotations vectors namespaces math assocs continuations peg
peg.parsers unicode.categories multiline combinators combinators.lib
splitting accessors effects sequences.deep peg.search inference
- io.streams.string io prettyprint ;
+ io.streams.string io prettyprint parser ;
IN: peg.ebnf
+: rule ( name word -- parser )
+ #! Given an EBNF word produced from EBNF: return the EBNF rule
+ "ebnf-parser" word-prop at ;
+
TUPLE: ebnf-non-terminal symbol ;
TUPLE: ebnf-terminal symbol ;
+TUPLE: ebnf-foreign word rule ;
TUPLE: ebnf-any-character ;
TUPLE: ebnf-range pattern ;
TUPLE: ebnf-ensure group ;
@@ -27,6 +32,7 @@ TUPLE: ebnf rules ;
C: <ebnf-non-terminal> ebnf-non-terminal
C: <ebnf-terminal> ebnf-terminal
+C: <ebnf-foreign> ebnf-foreign
C: <ebnf-any-character> ebnf-any-character
C: <ebnf-range> ebnf-range
C: <ebnf-ensure> ebnf-ensure
@@ -88,6 +94,8 @@ C: <ebnf> ebnf
[ dup CHAR: ? = ]
[ dup CHAR: : = ]
[ dup CHAR: ~ = ]
+ [ dup CHAR: < = ]
+ [ dup CHAR: > = ]
} 0|| not nip
] satisfy repeat1 [ >string <ebnf-non-terminal> ] action ;
@@ -96,6 +104,24 @@ C: <ebnf> ebnf
#! and it represents the literal value of the identifier.
'identifier' [ <ebnf-terminal> ] action ;
+: 'foreign-name' ( -- parser )
+ #! Parse a valid foreign parser name
+ [
+ {
+ [ dup blank? ]
+ [ dup CHAR: > = ]
+ } 0|| not nip
+ ] satisfy repeat1 [ >string ] action ;
+
+: 'foreign' ( -- parser )
+ #! A foreign call is a call to a rule in another ebnf grammar
+ [
+ "<foreign" syntax ,
+ 'foreign-name' sp ,
+ 'foreign-name' sp optional ,
+ ">" syntax ,
+ ] seq* [ first2 <ebnf-foreign> ] action ;
+
: 'any-character' ( -- parser )
#! A parser to match the symbol for any character match.
[ CHAR: . = ] satisfy [ drop <ebnf-any-character> ] action ;
@@ -117,6 +143,7 @@ C: <ebnf> ebnf
[
'non-terminal' ,
'terminal' ,
+ 'foreign' ,
'range-parser' ,
'any-character' ,
] choice* ,
@@ -367,6 +394,15 @@ M: ebnf-var (transform) ( ast -- parser )
M: ebnf-terminal (transform) ( ast -- parser )
symbol>> token ;
+M: ebnf-foreign (transform) ( ast -- parser )
+ dup word>> search
+ [ "Foreign word " swap word>> append " not found" append throw ] unless*
+ swap rule>> dup [
+ swap rule
+ ] [
+ execute
+ ] if ;
+
: parser-not-found ( name -- * )
[
"Parser " % % " not found." %
@@ -411,6 +447,3 @@ M: ebnf-non-terminal (transform) ( ast -- parser )
";EBNF" parse-multiline-string replace-escapes
ebnf>quot swapd 1 1 <effect> define-declared "ebnf-parser" set-word-prop ; parsing
-: rule ( name word -- parser )
- #! Given an EBNF word produced from EBNF: return the EBNF rule
- "ebnf-parser" word-prop at ;
\ No newline at end of file