move retry word to continuations

core/continuations/continuations-docs.factor

@@ -79,6 +79,7 @@ $nl
 { $subsection continue-with }
 "Continuations as control-flow:"
 { $subsection attempt-all }
+{ $subsection retry }
 { $subsection with-return }
 "Reflecting the datastack:"
 { $subsection with-datastack }
@@ -237,6 +238,20 @@ HELP: attempt-all
     }
 } ;
 
+HELP: retry
+{ $values
+     { "quot" quotation } { "n" null }
+}
+{ $description "Tries the quotation up to " { $snippet "n" } " times until it returns true. Retries the quotation if an exception is thrown or if the quotation returns " { $link f } ". The quotation is expected to have side effects that may fail, such as generating a random name for a new file until successful." }
+{ $examples
+    { $unchecked-example "USING: continuations math prettyprint ;"
+        "[ 5 random 0 = ] retry t"
+        "t"
+    }
+} ;
+
+{ attempt-all retry } related-words
+
 HELP: return
 { $description "Returns early from a quotation by reifying the continuation captured by " { $link with-return } " ; execution is resumed starting immediately after " { $link with-return } "." } ;
 

core/continuations/continuations.factor

@@ -154,6 +154,8 @@ ERROR: attempt-all-error ;
         ] { } make peek swap [ rethrow ] when
     ] if ; inline
 
+: retry ( quot: ( -- ? )  n -- ) swap [ drop ] prepose attempt-all ; inline
+
 TUPLE: condition error restarts continuation ;
 
 C: <condition> condition ( error restarts cc -- condition )