Implement Supply.uniq

rakudo · Apr 18, 2014 · 9ce36b9 · 9ce36b9
1 parent 3922904
commit 9ce36b9
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Showing 2 changed files with 67 additions and 7 deletions.
diff --git a/src/core/Supply.pm b/src/core/Supply.pm
@@ -81,13 +81,14 @@ my role Supply {
         }, *;
     }
 
-    method for(|c)          { SupplyOperations.for(|c) }
-    method interval(|c)     { SupplyOperations.interval(|c) }
-    method do(&side_effect) { SupplyOperations.do(self, &side_effect) }
-    method grep(&filter)    { SupplyOperations.grep(self, &filter) }
-    method map(&mapper)     { SupplyOperations.map(self, &mapper) }
-    method merge($s)        { SupplyOperations.merge(self, $s) }
-    method zip($s, *@with)  { SupplyOperations.zip(self, $s, |@with) }
+    method for(|c)           { SupplyOperations.for(|c) }
+    method interval(|c)      { SupplyOperations.interval(|c) }
+    method do(&side_effect)  { SupplyOperations.do(self, &side_effect) }
+    method grep(&filter)     { SupplyOperations.grep(self, &filter) }
+    method map(&mapper)      { SupplyOperations.map(self, &mapper) }
+    method uniq(:&as,:&with) { SupplyOperations.uniq(self, :&as, :&with) }
+    method merge($s)         { SupplyOperations.merge(self, $s) }
+    method zip($s, *@with)   { SupplyOperations.zip(self, $s, |@with) }
 }
 
 # The on meta-combinator provides a mechanism for implementing thread-safe

diff --git a/src/core/SupplyOperations.pm b/src/core/SupplyOperations.pm
@@ -101,6 +101,65 @@ my class SupplyOperations is repr('Uninstantiable') {
         }
         GrepSupply.new(:source($a), :&filter)
     }
+
+    method uniq(Supply $a, :&as, :&with) {
+        my class UniqSupply does Supply does PrivatePublishing {
+            has $!source;
+            has &!as;
+            has &!with;
+
+            submethod BUILD(:$!source, :&!as, :&!with) { }
+
+            method tap(|c) {
+                my $sub = self.Supply::tap(|c);
+                my &more = do {
+                    if &!with and &!with !=== &[===] {
+                        my @seen;  # should be Mu, but doesn't work in settings
+                        my Mu $target;
+                        &as
+                          ?? -> \val {
+                              $target = &!as(val);
+                              if @seen.first({ &!with($target,$_) } ) =:= Nil {
+                                  @seen.push($target);
+                                  self!more(val);
+                              }
+                          }
+                          !! -> \val {
+                              if @seen.first({ &!with(val,$_) } ) =:= Nil {
+                                  @seen.push(val);
+                                  self!more(val);
+                              }
+                          };
+                    }
+                    else {
+                        my $seen := nqp::hash();
+                        my str $target;
+                        &as
+                          ?? -> \val {
+                              $target = nqp::unbox_s(&!as(val).WHICH);
+                              unless nqp::existskey($seen, $target) {
+                                  nqp::bindkey($seen, $target, 1);
+                                  self!more(val);
+                              }
+                          }
+                          !! -> \val {
+                              $target = nqp::unbox_s(val.WHICH);
+                              unless nqp::existskey($seen, $target) {
+                                  nqp::bindkey($seen, $target, 1);
+                                  self!more(val);
+                              }
+                          };
+                    }
+                };
+                $!source.tap( &more,
+                  done => { self!done(); },
+                  quit => -> $ex { self!quit($ex) }
+                );
+                $sub
+            }
+        }
+        UniqSupply.new(:source($a), :&as, :&with);
+    }
 
     method map(Supply $a, &mapper) {
         my class MapSupply does Supply does PrivatePublishing {