Also make "last foo" work on .grep

If "foo" is true, then that value will be passed through and the iteration will be terminated. If the "foo" is false, then it will just terminate the iteration.
rakudo · Jun 19, 2021 · 8886a8d · 8886a8d
1 parent 7f093a0
commit 8886a8d
Showing 1 changed file with 73 additions and 42 deletions.
diff --git a/src/core.c/Any-iterable-methods.pm6 b/src/core.c/Any-iterable-methods.pm6
@@ -355,18 +355,15 @@ Consider using a block if any of these are necessary for your mapping code."
                         )
                       )
                     ),
-                    'LABELED',
-                    $!label,
-                    'NEXT',
-                    nqp::if(
+                    'LABELED', $!label,
+                    'NEXT', nqp::if(
                       nqp::eqaddr(
                         ($value := $!source.pull-one),IterationEnd
                       ),
                       ($result := IterationEnd),
                       ($redo = 1)
                     ),
-                    'REDO',
-                    ($redo = 1),
+                    'REDO', ($redo = 1),
                     'LAST', nqp::if(
                       nqp::isnull($result := nqp::getpayload(nqp::exception)),
                       ($result := IterationEnd),
@@ -511,18 +508,15 @@ Consider using a block if any of these are necessary for your mapping code."
                         )
                       )
                     ),
-                    'LABELED',
-                    $!label,
-                    'NEXT',
-                    nqp::if(
+                    'LABELED', $!label,
+                    'NEXT', nqp::if(
                       nqp::eqaddr(
                         ($value := $!source.pull-one),IterationEnd
                       ),
                       ($result := IterationEnd),
                       ($redo = 1)
                     ),
-                    'REDO',
-                    ($redo = 1),
+                    'REDO', ($redo = 1),
                     'LAST', nqp::if(
                       nqp::isnull($result := nqp::getpayload(nqp::exception)),
                       ($result  := IterationEnd),
@@ -916,43 +910,80 @@ Consider using a block if any of these are necessary for your mapping code."
         method is-deterministic(--> Bool:D) { $!iter.is-deterministic }
     }
     method !grep-callable(Callable:D $test) {
-        nqp::if(
-          $test.count == 1,
-          sequential-map(
-            self.iterator,
-            {
-                (nqp::istype((my \result := $test($_)),Regex)
-                  ?? result.ACCEPTS($_)
-                  !! nqp::istype(result,Junction)
-                    ?? result.Bool
-                    !! result
-                ) ?? $_
-                  !! Empty
-            },
-            Any)
-          ,
-          nqp::stmts(
-            (my role CheatArity {
+        my int $done;
+        if $test.count == 1 {
+            sequential-map(
+              self.iterator,
+              {
+                  nqp::if(
+                    $done,
+                    IterationEnd,
+                    nqp::if(
+                      nqp::stmts(
+                        nqp::handle(
+                          (my $result := $test($_)),
+                          'LAST', nqp::stmts(
+                            ($done = 1),
+                            ($result := nqp::ifnull(
+                              nqp::getpayload(nqp::exception),
+                              False
+                            ))
+                          )
+                        ),
+                        nqp::if(
+                          nqp::istype($result,Regex),
+                          $result.ACCEPTS($_),
+                          nqp::if(
+                            nqp::istype($result,Junction),
+                            $result.Bool,
+                            $result
+                          )
+                        )
+                      ),
+                      $_,
+                      Empty
+                    )
+                  )
+              },
+              Any
+            )
+        }
+        else {
+            my role CheatArity {
                 has $!arity;
                 has $!count;
 
-                method set-cheat($new-arity, $new-count --> Nil) {
-                    $!arity = $new-arity;
-                    $!count = $new-count;
+                method with-arity-count($new-arity, $new-count) {
+                    $!arity := $new-arity;
+                    $!count := $new-count;
+                    self
                 }
 
                 method arity(Code:D:) { $!arity }
                 method count(Code:D:) { $!count }
-            }),
-            (my &tester = -> |c {
-                #note "*cough* {c.raku} -> {$test(|c).raku}";
-                next unless $test(|c);
-                c.list
-            } but CheatArity),
-            &tester.set-cheat($test.arity, $test.count),
-            self.map(&tester)
-          )
-        )
+            }
+            my &tester := -> |c {
+                nqp::if(
+                  $done,
+                  IterationEnd,
+                  nqp::stmts(
+                    nqp::handle(
+                      (my $result := $test(|c)),
+                      'LAST', nqp::stmts(
+                        ($done = 1),
+                        ($result := nqp::ifnull(
+                          nqp::getpayload(nqp::exception),
+                          False
+                        ))
+                      )
+                    ),
+                    nqp::if($result,c.list,Empty)
+                  )
+                )
+            } but CheatArity;
+
+            self.map(&tester.with-arity-count($test.arity, $test.count))
+        }
     }
 
     # Create a braid and fail cursor that we can use with all the normal,