Fix peg.pl0 test failures

extra/peg/pl0/pl0-tests.factor

@@ -1,9 +1,54 @@
 ! Copyright (C) 2007 Chris Double.
 ! See http://factorcode.org/license.txt for BSD license.
 !
-USING: kernel tools.test peg peg.pl0 multiline sequences ;
+USING: kernel tools.test peg peg.pl0 multiline sequences words assocs ;
 IN: peg.pl0.tests
 
+{ f } [
+  "CONST foo = 1;" \ pl0 "ebnf-parser" word-prop "block" swap at parse not 
+] unit-test
+
+{ f } [
+  "VAR foo;" \ pl0 "ebnf-parser" word-prop "block" swap at parse not 
+] unit-test
+
+{ f } [
+  "VAR foo,bar , baz;" \ pl0 "ebnf-parser" word-prop "block" swap at parse not 
+] unit-test
+
+{ f } [
+  "foo := 5;" \ pl0 "ebnf-parser" word-prop "statement" swap at parse not 
+] unit-test
+
+{ f } [
+  "BEGIN foo := 5; END" \ pl0 "ebnf-parser" word-prop "statement" swap at parse not 
+] unit-test
+
+{ f } [
+  "IF 1=1 THEN foo := 5; END" \ pl0 "ebnf-parser" word-prop "statement" swap at parse not 
+] unit-test
+
+{ f } [
+  "WHILE 1=1 DO foo := 5; END" \ pl0 "ebnf-parser" word-prop "statement" swap at parse not 
+] unit-test
+
+{ f } [
+  "WHILE ODD 1=1 DO foo := 5; END" \ pl0 "ebnf-parser" word-prop "statement" swap at parse not 
+] unit-test
+
+{ f } [
+  "PROCEDURE square; BEGIN squ=x*x END" \ pl0 "ebnf-parser" word-prop "block" swap at parse not 
+] unit-test
+
+{ f } [
+  <"
+PROCEDURE square; 
+BEGIN 
+  squ := x * x 
+END;
+"> \ pl0 "ebnf-parser" word-prop "block" swap at parse not 
+] unit-test
+
 { t } [
   <"
 VAR x, squ;

extra/peg/pl0/pl0.factor

@@ -7,18 +7,20 @@ IN: peg.pl0
 #! Grammar for PL/0 based on http://en.wikipedia.org/wiki/PL/0
 
 EBNF: pl0 
-block = ( "CONST" ident "=" number ( "," ident "=" number )* ";" )?
+- = (" " | "\t" | "\n")+ => [[ drop ignore ]]
-        ( "VAR" ident ( "," ident )* ";" )?
+_ = (" " | "\t" | "\n")* => [[ drop ignore ]]
-        ( "PROCEDURE" ident ";" ( block ";" )? )* statement 
+block = ( _ "CONST" - ident _ "=" _ number ( _ "," _ ident _ "=" _ number )* _ ";" )?
-statement = ( ident ":=" expression | "CALL" ident |
+        ( _ "VAR" - ident ( _ "," _ ident )* _ ";" )?
-              "BEGIN" statement (";" statement )* "END" |
+        ( _ "PROCEDURE" - ident _ ";" ( _ block _ ";" )? )* _ statement
-              "IF" condition "THEN" statement |
+statement = ( ident _ ":=" _ expression | "CALL" - ident |
-              "WHILE" condition "DO" statement )?
+              "BEGIN" - statement ( _ ";" _ statement )* _ "END" |
-condition = "ODD" expression |
+              "IF" - condition _ "THEN" - statement |
-            expression ("=" | "#" | "<=" | "<" | ">=" | ">") expression 
+              "WHILE" - condition _ "DO" - statement )?
-expression = ("+" | "-")? term (("+" | "-") term )* 
+condition = "ODD" - expression |
-term = factor (("*" | "/") factor )* 
+            expression _ ("=" | "#" | "<=" | "<" | ">=" | ">") _ expression
-factor = ident | number | "(" expression ")"
+expression = ("+" | "-")? term ( _ ("+" | "-") _ term )* 
+term = factor ( _ ("*" | "/") _ factor )* 
+factor = ident | number | "(" _ expression _ ")"
 ident = (([a-zA-Z])+) [[ >string ]]
 digit = ([0-9]) [[ digit> ]]
 number = ((digit)+) [[ unclip [ swap 10 * + ] reduce ]]