parser: added helper word use-first-word? to simplify no-word

core/parser/parser-docs.factor

@@ -284,6 +284,10 @@ HELP: auto-use?
 { $var-description "If set to a true value, the behavior of the parser when encountering an unknown word name is changed. If only one loaded vocabulary has a word with this name, instead of throwing an error, the parser adds the vocabulary to the search path and prints a parse note. Off by default." }
 { $notes "This feature is intended to help during development. To generate a " { $link POSTPONE: USING: } " form automatically, enable " { $link auto-use? } ", load the source file, and copy and paste the " { $link POSTPONE: USING: } " form printed by the parser back into the file, then disable " { $link auto-use? } ". See " { $link "word-search-errors" } "." } ;
 
+HELP: use-first-word?
+{ $values { "words" sequence } { "?" boolean } }
+{ $description "Checks if the first word can be used automatically without first throwing a restartable " { $link no-word-error } } ;
+
 HELP: scan-object
 { $values { "object" object } }
 { $description "Parses a literal representation of an object." }

core/parser/parser-tests.factor

@@ -641,3 +641,9 @@ EXCLUDE: qualified.tests.bar => x ;
 
 [ "GENERIC: 33 ( -- )" <string-reader> "generic identifier test" parse-stream ]
 [ error>> lexer-error? ] must-fail-with
+
+{ t } [
+    t auto-use? [
+        { private? } use-first-word?
+    ] with-variable
+] unit-test

core/parser/parser.factor

@@ -36,17 +36,17 @@ SYMBOL: auto-use?
 
 : private? ( word -- ? ) vocabulary>> ".private" tail? ;
 
+: use-first-word? ( words -- ? )
+    [ length 1 = ] [ ?first dup [ private? not ] [ ] ?if ] bi and
+    auto-use? get and ;
+
 ! True branch is a singleton public word with no name conflicts
 ! False branch, singleton private words need confirmation regardless
 ! of name conflicts
 : no-word ( name -- newword )
     dup words-named ignore-forwards
-    dup [ length 1 = ]
-    [ [ f ] [ first private? not ] if-empty ] bi and
-    auto-use? get and
-    [ nip first no-word-restarted ]
-    [ <no-word-error> throw-restarts no-word-restarted ]
-    if ;
+    dup use-first-word? [ nip first ] [ <no-word-error> throw-restarts ] if
+    no-word-restarted ;
 
 : parse-word ( string -- word )
     dup search [ ] [ no-word ] ?if ;