Merge pull request #1077 from MasterDuke17/make_feed_compile_errors_b…

…etter Make feed compile errors better
rakudo · May 8, 2017 · 10e9d0c · 10e9d0c
2 parents 3f7d133 + 07c7ce1
commit 10e9d0c
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Showing 2 changed files with 28 additions and 11 deletions.
diff --git a/src/Perl6/Actions.nqp b/src/Perl6/Actions.nqp
@@ -6529,10 +6529,10 @@ class Perl6::Actions is HLL::Actions does STDActions {
         # Assemble into list of AST of each step in the pipeline.
         my @stages;
         if $/<infix><sym> eq '==>' {
-            for @($/) { @stages.push(WANTED($_.ast,'==>')); }
+            for @($/) { @stages.push($_); }
         }
         elsif $/<infix><sym> eq '<==' {
-            for @($/) { @stages.unshift(WANTED($_.ast,'<==')); }
+            for @($/) { @stages.unshift($_); }
         }
         else {
             $*W.throw($/, 'X::Comp::NYI',
@@ -6545,25 +6545,27 @@ class Perl6::Actions is HLL::Actions does STDActions {
         # will be passed in as var-arg parts to other things. The
         # first thing is just considered the result.
         my $result := @stages.shift;
+        $result    := WANTED($result.ast, $/<infix><sym>);
         for @stages {
+            my $stage := WANTED($_.ast, $/<infix><sym>);
             # Wrap current result in a block, so it's thunked and can be
             # called at the right point.
             $result := QAST::Block.new( $result );
 
             # Check what we have. XXX Real first step should be looking
             # for @(*) since if we find that it overrides all other things.
             # But that's todo...soon. :-)
-            if $_.isa(QAST::Op) && $_.op eq 'call' {
+            if $stage.isa(QAST::Op) && $stage.op eq 'call' {
                 # It's a call. Stick a call to the current supplier in
                 # as its last argument.
-                $_.push(QAST::Op.new( :op('call'), $result ));
+                $stage.push(QAST::Op.new( :op('call'), $result ));
             }
-            elsif $_ ~~ QAST::Var {
+            elsif $stage ~~ QAST::Var {
                 # It's a variable. We need code that gets the results, pushes
                 # them onto the variable and then returns them (since this
                 # could well be a tap.
                 my $tmp := QAST::Node.unique('feed_tmp');
-                $_ := QAST::Stmts.new(
+                $stage := QAST::Stmts.new(
                     QAST::Op.new(
                         :op('bind'),
                         QAST::Var.new( :scope('local'), :name($tmp), :decl('var') ),
@@ -6574,17 +6576,22 @@ class Perl6::Actions is HLL::Actions does STDActions {
                     ),
                     QAST::Op.new(
                         :op('callmethod'), :name('append'),
-                        $_,
+                        $stage,
                         QAST::Var.new( :scope('local'), :name($tmp) )
                     ),
                     QAST::Var.new( :scope('local'), :name($tmp) )
                 );
-                $_ := QAST::Op.new( :op('locallifetime'), $_, $tmp );
+                $stage := QAST::Op.new( :op('locallifetime'), $stage, $tmp );
             }
             else {
-                $/.panic('Sorry, do not know how to handle this case of a feed operator yet.');
+                my str $error := "Only routine calls or variables that can '.push' may appear on either side of feed operators.";
+                if $stage.isa(QAST::Op) && $stage.op eq 'ifnull' && $stage[0].isa(QAST::Var) && nqp::eqat($stage[0].name, '&', 0) {
+                    $error := "A feed may not sink values into a code object. Did you mean a call like '"
+                            ~ nqp::substr($stage[0].name, 1) ~ "()' instead?";
+                }
+                $_.PRECURSOR.panic($error);
             }
-            $result := $_;
+            $result := $stage;
         }
 
         # WANTED($result,'make_feed');

diff --git a/t/05-messages/01-errors.t b/t/05-messages/01-errors.t
@@ -99,10 +99,20 @@ throws-like ｢m: my @a = for 1..3 <-> { $_ }｣, Exception,
 }
 
 # adapted from S32-exceptions/misc.t
-for <fail die throw rethrow resumable resume> -> $meth {
+for <fail die throw rethrow resume> -> $meth {
     throws-like 'X::NYI.' ~ $meth,
         Exception,
         message => all(/'Invocant'/, /<<$meth>>/, /<<'must be an object instance'>>/, /<<'not a type object'>>/, /<<'Exception'>>/,  /<<'X::NYI'>>/, /\W '.new'>>/),
 }
 
+# RT #112396
+{
+    throws-like q|3 ==> &sin ==> &say|,
+        Exception,
+        message => /<<'sin()'\W/,
+        'sinking to a code object in a feed suggests calling the routine';
+}
+
 done-testing;
+
+# vim: ft=perl6 expandtab sw=4