Generalize type parameterization. T[...] now calls T.^parameterize(..…

….), and ParametricRoleGroupHOW gets to decide about CurriedRoleHOW, which is now an implementation details.

src/Perl6/Actions.pm

@@ -2705,18 +2705,18 @@ class Perl6::Actions is HLL::Actions {
                     }
                 }
                 if $all_compile_time {
-                    my $curried := $*ST.curry_role(%*HOW<role-curried>,
-                        $role, $<arglist>, $/);
+                    my $curried := $*ST.parameterize_type($role, $<arglist>, $/);
                     $past := $*ST.get_object_sc_ref_past($curried);
                     $past<has_compile_time_value> := 1;
                     $past<compile_time_value> := $curried;
                 }
                 else {
+                    my $rref := $*ST.get_object_sc_ref_past($role);
                     $past := $<arglist>[0].ast;
                     $past.pasttype('callmethod');
-                    $past.name('new_type');
-                    $past.unshift($*ST.get_object_sc_ref_past($role));
-                    $past.unshift($*ST.get_object_sc_ref_past(%*HOW<role-curried>));
+                    $past.name('parameterize');
+                    $past.unshift($rref);
+                    $past.unshift(PAST::Op.new( :pirop('get_how PP'), $rref ));
                 }
             }
             elsif ~$<longname> eq 'GLOBAL' {
@@ -3475,10 +3475,10 @@ class Perl6::Actions is HLL::Actions {
                 my $type := $*ST.find_symbol(Perl6::Grammar::parse_name(
                     Perl6::Grammar::canonical_type_longname($<longname>)));
                 if $<arglist> {
-                    $type := $*ST.curry_role(%*HOW<role-curried>, $type, $<arglist>, $/);
+                    $type := $*ST.parameterize_type($type, $<arglist>, $/);
                 }
                 if $<typename> {
-                    $type := $*ST.curry_role_with_args(%*HOW<role-curried>, $type,
+                    $type := $*ST.parameterize_type_with_args($type,
                         [$<typename>[0].ast], hash());
                 }
                 make $type;

src/Perl6/Metamodel/EXPORTHOW.pm

@@ -9,7 +9,6 @@ my module EXPORTHOW {
     ($?PACKAGE.WHO)<role>         := Perl6::Metamodel::ParametricRoleHOW;
     ($?PACKAGE.WHO)<role-attr>    := Attribute;
     ($?PACKAGE.WHO)<role-group>   := Perl6::Metamodel::ParametricRoleGroupHOW;
-    ($?PACKAGE.WHO)<role-curried> := Perl6::Metamodel::CurriedRoleHOW;
     ($?PACKAGE.WHO)<grammar>      := Perl6::Metamodel::GrammarHOW;
     ($?PACKAGE.WHO)<grammar-attr> := Attribute;
     ($?PACKAGE.WHO)<native>       := Perl6::Metamodel::NativeHOW;

src/Perl6/Metamodel/ParametricRoleGroupHOW.pm

@@ -10,6 +10,7 @@
 # group of those, and know how to specialize to a certain parameter
 # list by multi-dispatching over the set of possibilities to pick
 # a particular candidate.
+my $currier := Perl6::Metamodel::CurriedRoleHOW;
 class Perl6::Metamodel::ParametricRoleGroupHOW
     does Perl6::Metamodel::Naming
     does Perl6::Metamodel::Stashing
@@ -36,6 +37,10 @@ class Perl6::Metamodel::ParametricRoleGroupHOW
         self.add_stash(pir::repr_type_object_for__PPS($meta, 'Uninstantiable'));
     }
 
+    method parameterize($obj, *@pos_args, *%named_args) {
+        $currier.new_type($obj, |@pos_args, |%named_args)
+    }
+
     method add_possibility($obj, $possible) {
         @!possibilities[+@!possibilities] := $possible;
         @!add_to_selector[+@!add_to_selector] := $possible;
@@ -46,10 +51,10 @@ class Perl6::Metamodel::ParametricRoleGroupHOW
         # Locate correct parametric role and type environment.
         my $error;
         my @result;
-        try {
+        #try {
             @result := (self.get_selector($obj))(|@pos_args, |%named_args);
-            CATCH { $error := $! }
-        }
+        #    CATCH { $error := $! }
+        #}
         if $error {
             pir::die("None of the parametric role variants for '" ~
                 self.name($obj) ~ "' matched the arguments supplied.\n" ~

src/Perl6/SymbolTable.pm

@@ -1357,7 +1357,7 @@ class Perl6::SymbolTable is HLL::Compiler::SerializationContextBuilder {
     }
 
     # Builds a curried role based on a parsed argument list.
-    method curry_role($curryhow, $role, $arglist, $/) {
+    method parameterize_type($role, $arglist, $/) {
         # Build a list of compile time arguments to the role; whine if
         # we find something without one.
         my @pos_args;
@@ -1376,21 +1376,22 @@ class Perl6::SymbolTable is HLL::Compiler::SerializationContextBuilder {
             }
         }
 
-        self.curry_role_with_args($curryhow, $role, @pos_args, %named_args);
+        self.parameterize_type_with_args($role, @pos_args, %named_args);
     }
 
     # Curries a role with the specified arguments.
-    method curry_role_with_args($curryhow, $role, @pos_args, %named_args) {
+    method parameterize_type_with_args($role, @pos_args, %named_args) {
         # Make the curry right away and add it to the SC.
-        my $curried := $curryhow.new_type($role, |@pos_args, |%named_args);
+        my $curried := $role.HOW.parameterize($role, |@pos_args, |%named_args);
         my $slot := self.add_object($curried);
 
         # Serialize call.
         if self.is_precompilation_mode() {
+            my $rref := self.get_object_sc_ref_past($role);
             my $setup_call := PAST::Op.new(
-                :pasttype('callmethod'), :name('new_type'),
-                self.get_object_sc_ref_past($curryhow),
-                self.get_object_sc_ref_past($role)
+                :pasttype('callmethod'), :name('parameterize'),
+                PAST::Op.new( :pirop('get_how PP'), $rref ),
+                $rref
             );
             for @pos_args {
                 $setup_call.push(self.get_object_sc_ref_past($_));

src/core/EXPORTHOW.pm

@@ -9,7 +9,6 @@ my module EXPORTHOW {
     nqp::bindkey($?PACKAGE.WHO, 'role', Perl6::Metamodel::ParametricRoleHOW);
     nqp::bindkey($?PACKAGE.WHO, 'role-attr', Attribute);
     nqp::bindkey($?PACKAGE.WHO, 'role-group', Perl6::Metamodel::ParametricRoleGroupHOW);
-    nqp::bindkey($?PACKAGE.WHO, 'role-curried', Perl6::Metamodel::CurriedRoleHOW);
     nqp::bindkey($?PACKAGE.WHO, 'grammar', Perl6::Metamodel::GrammarHOW);
     nqp::bindkey($?PACKAGE.WHO, 'grammar-attr', Attribute);
     nqp::bindkey($?PACKAGE.WHO, 'native', Perl6::Metamodel::NativeHOW);