From a3413060bb9f4e33a02ba9b2273e168c2d143b73 Mon Sep 17 00:00:00 2001
From: Slava Pestov <slava@slava-pestovs-macbook-pro.local>
Date: Fri, 26 Mar 2010 03:42:07 -0400
Subject: [PATCH] lexer: each-token and map-tokens did not handle EOF properly

---
 core/lexer/lexer.factor         |  15 +-
 core/parser/parser-tests.factor | 514 ++++++++++++++++----------------
 core/syntax/syntax.factor       |   4 +-
 3 files changed, 268 insertions(+), 265 deletions(-)

diff --git a/core/lexer/lexer.factor b/core/lexer/lexer.factor
index 7f6324c251..f9554fa9bb 100644
--- a/core/lexer/lexer.factor
+++ b/core/lexer/lexer.factor
@@ -86,8 +86,7 @@ M: lexer skip-word ( lexer -- )
 
 : scan ( -- str/f ) lexer get parse-token ;
 
-PREDICATE: unexpected-eof < unexpected
-    got>> not ;
+PREDICATE: unexpected-eof < unexpected got>> not ;
 
 : unexpected-eof ( word -- * ) f unexpected ;
 
@@ -97,14 +96,15 @@ PREDICATE: unexpected-eof < unexpected
     [ unexpected-eof ]
     if* ;
 
-: (each-token) ( end quot -- pred quot )
-    [ [ [ scan dup ] ] dip [ = not ] curry [ [ f ] if* ] curry compose ] dip ; inline
-
 : each-token ( ... end quot: ( ... token -- ... ) -- ... )
-    (each-token) while drop ; inline
+    [ scan ] 2dip {
+        { [ 2over = ] [ 3drop ] }
+        { [ pick not ] [ drop unexpected-eof ] }
+        [ [ nip call ] [ each-token ] 2bi ]
+    } cond ; inline recursive
 
 : map-tokens ( ... end quot: ( ... token -- ... elt ) -- ... seq )
-    (each-token) produce nip ; inline
+    collector [ each-token ] dip ; inline
 
 : parse-tokens ( end -- seq )
     [ ] map-tokens ;
@@ -112,6 +112,7 @@ PREDICATE: unexpected-eof < unexpected
 TUPLE: lexer-error line column line-text parsing-words error ;
 
 M: lexer-error error-file error>> error-file ;
+
 M: lexer-error error-line [ error>> error-line ] [ line>> ] bi or ;
 
 : <lexer-error> ( msg -- error )
diff --git a/core/parser/parser-tests.factor b/core/parser/parser-tests.factor
index 266a65b957..ac2310d3f9 100644
--- a/core/parser/parser-tests.factor
+++ b/core/parser/parser-tests.factor
@@ -7,332 +7,334 @@ vocabs.parser words.symbol multiline source-files.errors
 tools.crossref grouping ;
 IN: parser.tests
 
+[ 1 [ 2 [ 3 ] 4 ] 5 ]
+[ "1\n[\n2\n[\n3\n]\n4\n]\n5" eval( -- a b c ) ]
+unit-test
+
+[ t t f f ]
+[ "t t f f" eval( -- ? ? ? ? ) ]
+unit-test
+
+[ "hello world" ]
+[ "\"hello world\"" eval( -- string ) ]
+unit-test
+
+[ "\n\r\t\\" ]
+[ "\"\\n\\r\\t\\\\\"" eval( -- string ) ]
+unit-test
+
+[ "hello world" ]
 [
-    [ 1 [ 2 [ 3 ] 4 ] 5 ]
-    [ "1\n[\n2\n[\n3\n]\n4\n]\n5" eval( -- a b c ) ]
-    unit-test
+    "IN: parser.tests : hello ( -- str ) \"hello world\" ;"
+    eval( -- ) "USE: parser.tests hello" eval( -- string )
+] unit-test
 
-    [ t t f f ]
-    [ "t t f f" eval( -- ? ? ? ? ) ]
-    unit-test
+[ ]
+[ "! This is a comment, people." eval( -- ) ]
+unit-test
 
-    [ "hello world" ]
-    [ "\"hello world\"" eval( -- string ) ]
-    unit-test
+! Test escapes
 
-    [ "\n\r\t\\" ]
-    [ "\"\\n\\r\\t\\\\\"" eval( -- string ) ]
-    unit-test
+[ " " ]
+[ "\"\\u000020\"" eval( -- string ) ]
+unit-test
 
-    [ "hello world" ]
-    [
-        "IN: parser.tests : hello ( -- str ) \"hello world\" ;"
-        eval( -- ) "USE: parser.tests hello" eval( -- string )
-    ] unit-test
+[ "'" ]
+[ "\"\\u000027\"" eval( -- string ) ]
+unit-test
 
-    [ ]
-    [ "! This is a comment, people." eval( -- ) ]
-    unit-test
+! Test EOL comments in multiline strings.
+[ "Hello" ] [ "#! This calls until-eol.\n\"Hello\"" eval( -- string ) ] unit-test
 
-    ! Test escapes
+[ word ] [ \ f class ] unit-test
 
-    [ " " ]
-    [ "\"\\u000020\"" eval( -- string ) ]
-    unit-test
+! Test stack effect parsing
 
-    [ "'" ]
-    [ "\"\\u000027\"" eval( -- string ) ]
-    unit-test
+: effect-parsing-test ( a b -- c ) + ;
 
-    ! Test EOL comments in multiline strings.
-    [ "Hello" ] [ "#! This calls until-eol.\n\"Hello\"" eval( -- string ) ] unit-test
+[ t ] [
+    "effect-parsing-test" "parser.tests" lookup
+    \ effect-parsing-test eq?
+] unit-test
 
-    [ word ] [ \ f class ] unit-test
+[ T{ effect f { "a" "b" } { "c" } f } ]
+[ \ effect-parsing-test "declared-effect" word-prop ] unit-test
 
-    ! Test stack effect parsing
+: baz ( a b -- * ) 2array throw ;
 
-    : effect-parsing-test ( a b -- c ) + ;
+[ t ]
+[ \ baz "declared-effect" word-prop terminated?>> ]
+unit-test
 
-    [ t ] [
-        "effect-parsing-test" "parser.tests" lookup
-        \ effect-parsing-test eq?
-    ] unit-test
+[ ] [ "IN: parser.tests USE: math : effect-parsing-test ( a b -- d ) - ;" eval( -- ) ] unit-test
 
-    [ T{ effect f { "a" "b" } { "c" } f } ]
-    [ \ effect-parsing-test "declared-effect" word-prop ] unit-test
+[ t ] [
+    "effect-parsing-test" "parser.tests" lookup
+    \ effect-parsing-test eq?
+] unit-test
 
-    : baz ( a b -- * ) 2array throw ;
+[ T{ effect f { "a" "b" } { "d" } f } ]
+[ \ effect-parsing-test "declared-effect" word-prop ] unit-test
 
-    [ t ]
-    [ \ baz "declared-effect" word-prop terminated?>> ]
-    unit-test
+[ "IN: parser.tests : missing-- ( a b ) ;" eval( -- ) ] must-fail
 
-    [ ] [ "IN: parser.tests USE: math : effect-parsing-test ( a b -- d ) - ;" eval( -- ) ] unit-test
+! Funny bug
+[ 2 ] [ "IN: parser.tests : \0. ( -- x ) 2 ; \0." eval( -- n ) ] unit-test
 
-    [ t ] [
-        "effect-parsing-test" "parser.tests" lookup
-        \ effect-parsing-test eq?
-    ] unit-test
+! These should throw errors
+[ "HEX: zzz" eval( -- obj ) ] must-fail
+[ "OCT: 999" eval( -- obj ) ] must-fail
+[ "BIN: --0" eval( -- obj ) ] must-fail
 
-    [ T{ effect f { "a" "b" } { "d" } f } ]
-    [ \ effect-parsing-test "declared-effect" word-prop ] unit-test
+DEFER: foo
 
-    ! Funny bug
-    [ 2 ] [ "IN: parser.tests : \0. ( -- x ) 2 ; \0." eval( -- n ) ] unit-test
+"IN: parser.tests USING: math prettyprint ; SYNTAX: foo 2 2 + . ;" eval( -- )
 
-    [ "IN: parser.tests : missing-- ( a b ) ;" eval( -- ) ] must-fail
+[ ] [ "USE: parser.tests foo" eval( -- ) ] unit-test
 
-    ! These should throw errors
-    [ "HEX: zzz" eval( -- obj ) ] must-fail
-    [ "OCT: 999" eval( -- obj ) ] must-fail
-    [ "BIN: --0" eval( -- obj ) ] must-fail
+"IN: parser.tests USING: math prettyprint ; : foo ( -- ) 2 2 + . ;" eval( -- )
 
-    DEFER: foo
+[ t ] [
+    "USE: parser.tests \\ foo" eval( -- word )
+    "foo" "parser.tests" lookup eq?
+] unit-test
 
-    "IN: parser.tests USING: math prettyprint ; SYNTAX: foo 2 2 + . ;" eval( -- )
+! parse-tokens should do the right thing on EOF
+[ "USING: kernel" eval( -- ) ]
+[ error>> T{ unexpected { want ";" } } = ] must-fail-with
 
-    [ ] [ "USE: parser.tests foo" eval( -- ) ] unit-test
+! Test smudging
 
-    "IN: parser.tests USING: math prettyprint ; : foo ( -- ) 2 2 + . ;" eval( -- )
+[ 1 ] [
+    "IN: parser.tests : smudge-me ( -- ) ;" <string-reader> "foo"
+    parse-stream drop
 
-    [ t ] [
-        "USE: parser.tests \\ foo" eval( -- word )
-        "foo" "parser.tests" lookup eq?
-    ] unit-test
+    "foo" source-file definitions>> first assoc-size
+] unit-test
 
-    ! Test smudging
+[ t ] [ "smudge-me" "parser.tests" lookup >boolean ] unit-test
 
-    [ 1 ] [
-        "IN: parser.tests : smudge-me ( -- ) ;" <string-reader> "foo"
-        parse-stream drop
+[ ] [
+    "IN: parser.tests : smudge-me-more ( -- ) ;" <string-reader> "foo"
+    parse-stream drop
+] unit-test
 
-        "foo" source-file definitions>> first assoc-size
-    ] unit-test
+[ t ] [ "smudge-me-more" "parser.tests" lookup >boolean ] unit-test
+[ f ] [ "smudge-me" "parser.tests" lookup >boolean ] unit-test
 
-    [ t ] [ "smudge-me" "parser.tests" lookup >boolean ] unit-test
+[ 3 ] [
+    "IN: parser.tests USING: math strings ; GENERIC: smudge-me ( a -- b ) M: integer smudge-me ; M: string smudge-me ;" <string-reader> "foo"
+    parse-stream drop
 
-    [ ] [
-        "IN: parser.tests : smudge-me-more ( -- ) ;" <string-reader> "foo"
-        parse-stream drop
-    ] unit-test
+    "foo" source-file definitions>> first assoc-size
+] unit-test
 
-    [ t ] [ "smudge-me-more" "parser.tests" lookup >boolean ] unit-test
-    [ f ] [ "smudge-me" "parser.tests" lookup >boolean ] unit-test
+[ 1 ] [
+    "IN: parser.tests USING: arrays ; M: array smudge-me ;" <string-reader> "bar"
+    parse-stream drop
 
-    [ 3 ] [
-        "IN: parser.tests USING: math strings ; GENERIC: smudge-me ( a -- b ) M: integer smudge-me ; M: string smudge-me ;" <string-reader> "foo"
-        parse-stream drop
+    "bar" source-file definitions>> first assoc-size
+] unit-test
 
-        "foo" source-file definitions>> first assoc-size
-    ] unit-test
+[ 2 ] [
+    "IN: parser.tests USING: math strings ; GENERIC: smudge-me ( a -- b ) M: integer smudge-me ;" <string-reader> "foo"
+    parse-stream drop
 
-    [ 1 ] [
-        "IN: parser.tests USING: arrays ; M: array smudge-me ;" <string-reader> "bar"
-        parse-stream drop
+    "foo" source-file definitions>> first assoc-size
+] unit-test
 
-        "bar" source-file definitions>> first assoc-size
-    ] unit-test
+[ t ] [
+    array "smudge-me" "parser.tests" lookup order member-eq?
+] unit-test
 
-    [ 2 ] [
-        "IN: parser.tests USING: math strings ; GENERIC: smudge-me ( a -- b ) M: integer smudge-me ;" <string-reader> "foo"
-        parse-stream drop
+[ t ] [
+    integer "smudge-me" "parser.tests" lookup order member-eq?
+] unit-test
 
-        "foo" source-file definitions>> first assoc-size
-    ] unit-test
-    
-    [ t ] [
-        array "smudge-me" "parser.tests" lookup order member-eq?
-    ] unit-test
-    
-    [ t ] [
-        integer "smudge-me" "parser.tests" lookup order member-eq?
-    ] unit-test
-    
-    [ f ] [
-        string "smudge-me" "parser.tests" lookup order member-eq?
-    ] unit-test
+[ f ] [
+    string "smudge-me" "parser.tests" lookup order member-eq?
+] unit-test
 
-    [ ] [
-        "IN: parser.tests USE: math 2 2 +" <string-reader> "a"
-        parse-stream drop
-    ] unit-test
-    
-    [ t ] [
-        "a" <pathname> \ + usage member?
-    ] unit-test
+[ ] [
+    "IN: parser.tests USE: math 2 2 +" <string-reader> "a"
+    parse-stream drop
+] unit-test
 
-    [ ] [
-        "IN: parser.tests USE: math 2 2 -" <string-reader> "a"
-        parse-stream drop
-    ] unit-test
-    
-    [ f ] [
-        "a" <pathname> \ + usage member?
-    ] unit-test
-    
-    [ ] [
-        "a" source-files get delete-at
-        2 [
-            "IN: parser.tests DEFER: x : y ( -- ) x ; : x ( -- ) y ;"
-            <string-reader> "a" parse-stream drop
-        ] times
-    ] unit-test
-    
+[ t ] [
+    "a" <pathname> \ + usage member?
+] unit-test
+
+[ ] [
+    "IN: parser.tests USE: math 2 2 -" <string-reader> "a"
+    parse-stream drop
+] unit-test
+
+[ f ] [
+    "a" <pathname> \ + usage member?
+] unit-test
+
+[ ] [
     "a" source-files get delete-at
-
-    [
-        "IN: parser.tests : x ( -- ) ; : y ( -- * ) 3 throw ; this is an error"
-        <string-reader> "a" parse-stream
-    ] [ source-file-error? ] must-fail-with
-
-    [ t ] [
-        "y" "parser.tests" lookup >boolean
-    ] unit-test
-
-    [ f ] [
-        "IN: parser.tests : x ( -- ) ;"
+    2 [
+        "IN: parser.tests DEFER: x : y ( -- ) x ; : x ( -- ) y ;"
         <string-reader> "a" parse-stream drop
-        
-        "y" "parser.tests" lookup
-    ] unit-test
+    ] times
+] unit-test
 
-    ! Test new forward definition logic
-    [ ] [
-        "IN: axx : axx ( -- ) ;"
-        <string-reader> "axx" parse-stream drop
-    ] unit-test
+"a" source-files get delete-at
 
-    [ ] [
-        "USE: axx IN: bxx : bxx ( -- ) ; : cxx ( -- ) axx bxx ;"
-        <string-reader> "bxx" parse-stream drop
-    ] unit-test
+[
+    "IN: parser.tests : x ( -- ) ; : y ( -- * ) 3 throw ; this is an error"
+    <string-reader> "a" parse-stream
+] [ source-file-error? ] must-fail-with
 
-    ! So we move the bxx word to axx...
-    [ ] [
-        "IN: axx : axx ( -- ) ; : bxx ( -- ) ;"
-        <string-reader> "axx" parse-stream drop
-    ] unit-test
+[ t ] [
+    "y" "parser.tests" lookup >boolean
+] unit-test
 
-    [ t ] [ "bxx" "axx" lookup >boolean ] unit-test
-
-    ! And reload the file that uses it...
-    [ ] [
-        "USE: axx IN: bxx ( -- ) : cxx ( -- ) axx bxx ;"
-        <string-reader> "bxx" parse-stream drop
-    ] unit-test
+[ f ] [
+    "IN: parser.tests : x ( -- ) ;"
+    <string-reader> "a" parse-stream drop
     
-    ! And hope not to get a forward-error!
+    "y" "parser.tests" lookup
+] unit-test
 
-    ! Turning a generic into a non-generic could cause all
-    ! kinds of funnyness
-    [ ] [
-        "IN: ayy USE: kernel GENERIC: ayy ( a -- b ) M: object ayy ;"
-        <string-reader> "ayy" parse-stream drop
-    ] unit-test
+! Test new forward definition logic
+[ ] [
+    "IN: axx : axx ( -- ) ;"
+    <string-reader> "axx" parse-stream drop
+] unit-test
 
-    [ ] [
-        "IN: ayy USE: kernel : ayy ( -- ) ;"
-        <string-reader> "ayy" parse-stream drop
-    ] unit-test
+[ ] [
+    "USE: axx IN: bxx : bxx ( -- ) ; : cxx ( -- ) axx bxx ;"
+    <string-reader> "bxx" parse-stream drop
+] unit-test
 
-    [ ] [
-        "IN: azz TUPLE: my-class ; GENERIC: a-generic ( a -- b )"
-        <string-reader> "azz" parse-stream drop
-    ] unit-test
+! So we move the bxx word to axx...
+[ ] [
+    "IN: axx : axx ( -- ) ; : bxx ( -- ) ;"
+    <string-reader> "axx" parse-stream drop
+] unit-test
 
-    [ ] [
-        "USE: azz M: my-class a-generic ;"
-        <string-reader> "azz-2" parse-stream drop
-    ] unit-test
+[ t ] [ "bxx" "axx" lookup >boolean ] unit-test
 
-    [ ] [
-        "IN: azz GENERIC: a-generic ( a -- b )"
-        <string-reader> "azz" parse-stream drop
-    ] unit-test
+! And reload the file that uses it...
+[ ] [
+    "USE: axx IN: bxx ( -- ) : cxx ( -- ) axx bxx ;"
+    <string-reader> "bxx" parse-stream drop
+] unit-test
 
-    [ ] [
-        "USE: azz USE: math M: integer a-generic ;"
-        <string-reader> "azz-2" parse-stream drop
-    ] unit-test
+! And hope not to get a forward-error!
 
-    [ ] [
-        "IN: parser.tests : <bogus-error> ( -- ) ; : bogus ( -- error ) <bogus-error> ;"
-        <string-reader> "bogus-error" parse-stream drop
-    ] unit-test
+! Turning a generic into a non-generic could cause all
+! kinds of funnyness
+[ ] [
+    "IN: ayy USE: kernel GENERIC: ayy ( a -- b ) M: object ayy ;"
+    <string-reader> "ayy" parse-stream drop
+] unit-test
 
-    [ ] [
-        "IN: parser.tests TUPLE: bogus-error ; C: <bogus-error> bogus-error : bogus ( -- error ) <bogus-error> ;"
-        <string-reader> "bogus-error" parse-stream drop
-    ] unit-test
+[ ] [
+    "IN: ayy USE: kernel : ayy ( -- ) ;"
+    <string-reader> "ayy" parse-stream drop
+] unit-test
 
-    ! Problems with class predicates -vs- ordinary words
-    [ ] [
-        "IN: parser.tests TUPLE: killer ;"
-        <string-reader> "removing-the-predicate" parse-stream drop
-    ] unit-test
+[ ] [
+    "IN: azz TUPLE: my-class ; GENERIC: a-generic ( a -- b )"
+    <string-reader> "azz" parse-stream drop
+] unit-test
 
-    [ ] [
-        "IN: parser.tests GENERIC: killer? ( a -- b )"
-        <string-reader> "removing-the-predicate" parse-stream drop
-    ] unit-test
-    
-    [ t ] [
-        "killer?" "parser.tests" lookup >boolean
-    ] unit-test
+[ ] [
+    "USE: azz M: my-class a-generic ;"
+    <string-reader> "azz-2" parse-stream drop
+] unit-test
 
-    [
-        "IN: parser.tests TUPLE: another-pred-test ; GENERIC: another-pred-test? ( a -- b )"
-        <string-reader> "removing-the-predicate" parse-stream
-    ] [ error>> error>> error>> redefine-error? ] must-fail-with
+[ ] [
+    "IN: azz GENERIC: a-generic ( a -- b )"
+    <string-reader> "azz" parse-stream drop
+] unit-test
 
-    [
-        "IN: parser.tests TUPLE: class-redef-test ; TUPLE: class-redef-test ;"
-        <string-reader> "redefining-a-class-1" parse-stream
-    ] [ error>> error>> error>> redefine-error? ] must-fail-with
+[ ] [
+    "USE: azz USE: math M: integer a-generic ;"
+    <string-reader> "azz-2" parse-stream drop
+] unit-test
 
-    [ ] [
-        "IN: parser.tests TUPLE: class-redef-test ; SYMBOL: class-redef-test"
-        <string-reader> "redefining-a-class-2" parse-stream drop
-    ] unit-test
+[ ] [
+    "IN: parser.tests : <bogus-error> ( -- ) ; : bogus ( -- error ) <bogus-error> ;"
+    <string-reader> "bogus-error" parse-stream drop
+] unit-test
 
-    [
-        "IN: parser.tests TUPLE: class-redef-test ; SYMBOL: class-redef-test : class-redef-test ( -- ) ;"
-        <string-reader> "redefining-a-class-3" parse-stream drop
-    ] [ error>> error>> error>> redefine-error? ] must-fail-with
+[ ] [
+    "IN: parser.tests TUPLE: bogus-error ; C: <bogus-error> bogus-error : bogus ( -- error ) <bogus-error> ;"
+    <string-reader> "bogus-error" parse-stream drop
+] unit-test
 
-    [ ] [
-        "IN: parser.tests TUPLE: class-fwd-test ;"
-        <string-reader> "redefining-a-class-3" parse-stream drop
-    ] unit-test
+! Problems with class predicates -vs- ordinary words
+[ ] [
+    "IN: parser.tests TUPLE: killer ;"
+    <string-reader> "removing-the-predicate" parse-stream drop
+] unit-test
 
-    [
-        "IN: parser.tests \\ class-fwd-test"
-        <string-reader> "redefining-a-class-3" parse-stream drop
-    ] [ error>> error>> error>> no-word-error? ] must-fail-with
+[ ] [
+    "IN: parser.tests GENERIC: killer? ( a -- b )"
+    <string-reader> "removing-the-predicate" parse-stream drop
+] unit-test
 
-    [ ] [
-        "IN: parser.tests TUPLE: class-fwd-test ; SYMBOL: class-fwd-test"
-        <string-reader> "redefining-a-class-3" parse-stream drop
-    ] unit-test
+[ t ] [
+    "killer?" "parser.tests" lookup >boolean
+] unit-test
 
-    [
-        "IN: parser.tests \\ class-fwd-test"
-        <string-reader> "redefining-a-class-3" parse-stream drop
-    ] [ error>> error>> error>> no-word-error? ] must-fail-with
+[
+    "IN: parser.tests TUPLE: another-pred-test ; GENERIC: another-pred-test? ( a -- b )"
+    <string-reader> "removing-the-predicate" parse-stream
+] [ error>> error>> error>> redefine-error? ] must-fail-with
 
-    [
-        "IN: parser.tests : foo ( -- ) ; TUPLE: foo ;"
-        <string-reader> "redefining-a-class-4" parse-stream drop
-    ] [ error>> error>> error>> redefine-error? ] must-fail-with
+[
+    "IN: parser.tests TUPLE: class-redef-test ; TUPLE: class-redef-test ;"
+    <string-reader> "redefining-a-class-1" parse-stream
+] [ error>> error>> error>> redefine-error? ] must-fail-with
 
-    [ ] [
-        "IN: parser.tests : foo ( x y -- z ) 1 2 ; : bar ( a -- b ) ;" eval( -- )
-    ] unit-test
+[ ] [
+    "IN: parser.tests TUPLE: class-redef-test ; SYMBOL: class-redef-test"
+    <string-reader> "redefining-a-class-2" parse-stream drop
+] unit-test
 
-    [
-        "IN: parser.tests : foo ( x y -- z) 1 2 ; : bar ( a -- b ) ;" eval( -- )
-    ] must-fail
-] with-file-vocabs
+[
+    "IN: parser.tests TUPLE: class-redef-test ; SYMBOL: class-redef-test : class-redef-test ( -- ) ;"
+    <string-reader> "redefining-a-class-3" parse-stream drop
+] [ error>> error>> error>> redefine-error? ] must-fail-with
+
+[ ] [
+    "IN: parser.tests TUPLE: class-fwd-test ;"
+    <string-reader> "redefining-a-class-3" parse-stream drop
+] unit-test
+
+[
+    "IN: parser.tests \\ class-fwd-test"
+    <string-reader> "redefining-a-class-3" parse-stream drop
+] [ error>> error>> error>> no-word-error? ] must-fail-with
+
+[ ] [
+    "IN: parser.tests TUPLE: class-fwd-test ; SYMBOL: class-fwd-test"
+    <string-reader> "redefining-a-class-3" parse-stream drop
+] unit-test
+
+[
+    "IN: parser.tests \\ class-fwd-test"
+    <string-reader> "redefining-a-class-3" parse-stream drop
+] [ error>> error>> error>> no-word-error? ] must-fail-with
+
+[
+    "IN: parser.tests : foo ( -- ) ; TUPLE: foo ;"
+    <string-reader> "redefining-a-class-4" parse-stream drop
+] [ error>> error>> error>> redefine-error? ] must-fail-with
+
+[ ] [
+    "IN: parser.tests : foo ( x y -- z ) 1 2 ; : bar ( a -- b ) ;" eval( -- )
+] unit-test
+
+[
+    "IN: parser.tests : foo ( x y -- z) 1 2 ; : bar ( a -- b ) ;" eval( -- )
+] must-fail
 
 [ ] [
     "IN: parser.tests USE: kernel PREDICATE: foo < object ( x -- y ) ;" eval( -- )
diff --git a/core/syntax/syntax.factor b/core/syntax/syntax.factor
index 84a753fb1b..bd70b0be62 100644
--- a/core/syntax/syntax.factor
+++ b/core/syntax/syntax.factor
@@ -1,4 +1,4 @@
-! Copyright (C) 2004, 2009 Slava Pestov.
+! Copyright (C) 2004, 2010 Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
 USING: accessors alien arrays byte-arrays byte-vectors definitions generic
 hashtables kernel math namespaces parser lexer sequences strings
@@ -125,7 +125,7 @@ IN: bootstrap.syntax
     ] define-core-syntax
 
     "SYMBOLS:" [
-        ";" [ create-in dup reset-generic define-symbol ] each-token
+        ";" [ create-in [ reset-generic ] [ define-symbol ] bi ] each-token
     ] define-core-syntax
 
     "SINGLETONS:" [