core: \foo is literally just foo. To escape it, do ``\ foo`` instead.

Fix smalltalk too.

core/effects/parser/parser.factor

@@ -81,7 +81,7 @@ ERROR: can't-nest-definitions word ;
 
 : (:) ( -- word def effect )
     [
-        scan-new-word
+        scan-new-syntax-word
         scan-effect
         parse-definition swap
     ] with-definition ;

core/lexer/lexer.factor

@@ -118,10 +118,16 @@ DEFER: parse-token
         nip
     ] if ;
 
+: unescape-token ( string -- string' )
+    dup length 1 = [ "\\" ?head drop ] unless ;
+
+: unescape-tokens ( seq -- seq' )
+    [ unescape-token ] map ;
+
 : parse-token ( lexer -- str/f )
     dup parse-raw [ skip-comments ] [ drop f ] if* ;
 
-: ?scan-token ( -- str/f ) lexer get parse-token ;
+: ?scan-token ( -- str/f ) lexer get parse-token unescape-token ;
 
 PREDICATE: unexpected-eof < unexpected got>> not ;
 
@@ -143,12 +149,6 @@ PREDICATE: unexpected-eof < unexpected got>> not ;
 : parse-tokens ( end -- seq )
     [ ] map-tokens ;
 
-: unescape-token ( string -- string' )
-    "\\" ?head drop ;
-
-: unescape-tokens ( seq -- seq' )
-    [ unescape-token ] map ;
-
 TUPLE: lexer-error line column line-text parsing-words error ;
 
 M: lexer-error error-file error>> error-file ;

extra/smalltalk/compiler/compiler.factor

@@ -26,14 +26,14 @@ M: ast-name compile-ast name>> swap lookup-reader ;
     [ compile-arguments ] 2bi
     [ new ] 3append ;
 
-: compile-ifTrue:ifFalse: ( lexenv ast -- quot )
+: \compile-ifTrue:ifFalse: ( lexenv ast -- quot )
     [ receiver>> compile-ast ]
     [ compile-arguments ] 2bi
     [ if ] 3append ;
 
 M: ast-message-send compile-ast
     dup selector>> {
-        { "ifTrue:ifFalse:" [ compile-ifTrue:ifFalse: ] }
+        { "ifTrue:ifFalse:" [ \compile-ifTrue:ifFalse: ] }
         { "new" [ compile-new ] }
         [
             drop

extra/smalltalk/library/library.factor

@@ -17,8 +17,8 @@ SELECTOR: tab
 SELECTOR: nl
 
 M: object selector-print: [ present ] dip stream-print nil ;
-M: object selector-nextPutAll: selector-print: ;
+M: object selector-nextPutAll: \selector-print: ;
-M: object selector-tab "    " swap selector-print: ;
+M: object selector-tab "    " swap \selector-print: ;
 M: object selector-nl stream-nl nil ;
 
 SELECTOR: +