Good error on parameterizing a non-parametric.

Now it shows what went wrong and where, rather than just a method not found error.
rakudo · Jul 15, 2015 · e4077e3 · e4077e3
1 parent d378509
commit e4077e3
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Showing 3 changed files with 19 additions and 9 deletions.
diff --git a/src/Perl6/Actions.nqp b/src/Perl6/Actions.nqp
@@ -3988,7 +3988,7 @@ Compilation unit '$file' contained the following violations:
             }
             if $need_role {
                 if nqp::existskey(%*PARAM_INFO, 'nominal_type') {
-                    %*PARAM_INFO<nominal_type> := $*W.parameterize_type_with_args(
+                    %*PARAM_INFO<nominal_type> := $*W.parameterize_type_with_args($/,
                         $role_type, [%*PARAM_INFO<nominal_type>], nqp::hash());
                 }
                 else {
@@ -6191,7 +6191,7 @@ Compilation unit '$file' contained the following violations:
                         $<accept> ?? $<accept>.ast !! $*W.find_symbol(['Any']));
                 }
                 elsif $<typename> {
-                    $type := $*W.parameterize_type_with_args($type,
+                    $type := $*W.parameterize_type_with_args($/, $type,
                         [$<typename>.ast], hash());
                 }
                 make $type;

diff --git a/src/Perl6/World.nqp b/src/Perl6/World.nqp
@@ -1180,9 +1180,9 @@ class Perl6::World is HLL::World {
                 my $vtype              := @value_type[0];
                 my $base_type_name     := nqp::objprimspec($vtype) ?? 'array' !! 'Array';
                 %info<container_base>  := self.find_symbol([$base_type_name]);
-                %info<container_type>  := self.parameterize_type_with_args(
+                %info<container_type>  := self.parameterize_type_with_args($/,
                     %info<container_base>, [$vtype], nqp::hash());
-                %info<bind_constraint> := self.parameterize_type_with_args(
+                %info<bind_constraint> := self.parameterize_type_with_args($/,
                     %info<bind_constraint>, [$vtype], nqp::hash());
                 %info<value_type>      := $vtype;
                 %info<default_value>   := $vtype;
@@ -1232,9 +1232,9 @@ class Perl6::World is HLL::World {
                     self.throw($/, 'X::Comp::NYI',
                       feature => "native value types for hashes");
                 }
-                %info<container_type>  := self.parameterize_type_with_args(
+                %info<container_type>  := self.parameterize_type_with_args($/,
                     %info<container_base>, @value_type, nqp::hash());
-                %info<bind_constraint> := self.parameterize_type_with_args(
+                %info<bind_constraint> := self.parameterize_type_with_args($/,
                     %info<bind_constraint>, @value_type, nqp::hash());
                 %info<value_type>      := @value_type[0];
                 %info<default_value>   := @value_type[0];
@@ -1250,7 +1250,7 @@ class Perl6::World is HLL::World {
             %info<container_type>  := %info<container_base>;
             %info<bind_constraint> := self.find_symbol(['Callable']);
             if @value_type {
-                %info<bind_constraint> := self.parameterize_type_with_args(
+                %info<bind_constraint> := self.parameterize_type_with_args($/,
                     %info<bind_constraint>, [@value_type[0]], nqp::hash());
             }
             %info<value_type>     := %info<bind_constraint>;
@@ -2457,13 +2457,16 @@ class Perl6::World is HLL::World {
             }
         }
 
-        self.parameterize_type_with_args($role, @pos_args, %named_args);
+        self.parameterize_type_with_args($/, $role, @pos_args, %named_args);
     }
 
     # Curries a role with the specified arguments.
-    method parameterize_type_with_args($role, @pos_args, %named_args) {
+    method parameterize_type_with_args($/, $role, @pos_args, %named_args) {
         # Make the curry right away and add it to the SC.
         if @pos_args || %named_args {
+            unless nqp::can($role.HOW, 'parameterize') {
+                self.throw($/, 'X::NotParametric', type => $role);
+            }
             my $curried := $role.HOW.parameterize($role, |@pos_args, |%named_args);
             self.add_object($curried);
             return $curried;

diff --git a/src/core/Exception.pm b/src/core/Exception.pm
@@ -2039,4 +2039,11 @@ my class X::TooLateForREPR is X::Comp  {
     }
 }
 
+my class X::NotParametric is Exception {
+    has $.type;
+    method message() {
+        "$!type.^name() cannot be parameterized";
+    }
+}
+
 # vim: ft=perl6 expandtab sw=4