Fix "class A is B{}" LTA error

Partial fix to R#2052
rakudo · Jul 12, 2018 · 1956df2 · 1956df2
1 parent 8f09082
commit 1956df2
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diff --git a/src/core/Exception.pm6 b/src/core/Exception.pm6
@@ -1389,6 +1389,14 @@ my class X::Syntax::KeywordAsFunction does X::Syntax {
     }
 }
 
+my class X::Syntax::ParentAsHash does X::Syntax {
+    has $.parent;
+    method message() {
+        "Syntax error while specifying a parent class:\n"
+        ~ "Must specify a space between {$.parent.^name} and \{";
+    }
+}  
+
 my class X::Syntax::Malformed::Elsif does X::Syntax {
     has $.what = 'else if';
     method message() { qq{In Perl 6, please use "elsif' instead of "$.what"} }

diff --git a/src/core/traits.pm6 b/src/core/traits.pm6
@@ -1,4 +1,5 @@
 # for errors
+my class X::Syntax::ParentAsHash { ... }
 my class X::Inheritance::Unsupported { ... }
 my class X::Inheritance::UnknownParent { ... }
 my class X::Export::NameClash        { ... }
@@ -59,6 +60,9 @@ multi sub trait_mod:<is>(Mu:U $type, :$hidden!) {
 multi sub trait_mod:<is>(Mu:U $type, Mu :$array_type!) {
     $type.^set_array_type($array_type);
 }
+multi sub trait_mod:<is>(Mu:U $type, Mu:U $parent, Hash) {
+    X::Syntax::ParentAsHash.new(:$parent).throw;
+}
 multi sub trait_mod:<is>(Mu:U $type, *%fail) {
     if %fail.keys[0] !eq $type.^name {
         X::Inheritance::UnknownParent.new(