Implement ||= and &&=, and re-work //= to short-circuit.

rakudo · Mar 17, 2009 · b117c67 · b117c67
1 parent 1ea27f2
commit b117c67
Show file tree

Hide file tree

Showing 3 changed files with 16 additions and 17 deletions.
diff --git a/src/builtins/assign.pir b/src/builtins/assign.pir
@@ -202,23 +202,6 @@ src/builtins/assign.pir - assignments
 .end
 
 
-=item infix:<//=>
-
-Implemented here as infix:// reduces to a PAST node rather than a call.
-
-=cut
-
-.sub 'infix://='
-    .param pmc a
-    .param pmc b
-    $I0 = 'defined'(a)
-    if $I0 goto done
-    'infix:='(a, b)
-  done:
-    .return (a)
-.end
-
-
 .sub '!REDUCEMETAOPCHAIN'
     .param string opname
     .param string identity

diff --git a/src/parser/actions.pm b/src/parser/actions.pm
@@ -2586,6 +2586,20 @@ method EXPR($/, $key) {
         $past.flat(1);
         make $past;
     }
+    elsif ~$type eq 'infix://=' || ~$type eq 'infix:||=' || ~$type eq 'infix:&&=' {
+        my $lhs := $( $/[0] );
+        my $rhs := $( $/[1] );
+        make PAST::Op.new(
+            :pasttype('call'),
+            :name('infix:='),
+            $lhs,
+            PAST::Op.new($lhs, $rhs, :pasttype(
+                ~$type eq 'infix://=' ?? 'def_or' !!
+                (~$type eq 'infix:||=' ?? 'unless' !!
+                 'if'))
+            )
+        );
+    }
     else {
         my $past := PAST::Op.new(
             :node($/),

diff --git a/src/parser/grammar-oper.pg b/src/parser/grammar-oper.pg
@@ -144,6 +144,8 @@ proto infix:<::=> is equiv(infix:<:=>) { ... }
 proto infix:<.=> is equiv(infix:<:=>) { ... }
 proto infix:«=>» is equiv(infix:<:=>) { ... }
 proto infix:<//=> is equiv(infix:<:=>) { ... }
+proto infix:<&&=> is equiv(infix:<:=>) { ... }
+proto infix:<||=> is equiv(infix:<:=>) { ... }
 
 ## loose unary
 proto prefix:<true> is precedence('h=') is subname('true') { ... }