Try to awesomify error for #123834

rakudo · Feb 15, 2015 · 6245cfb · 6245cfb
1 parent 0b48529
commit 6245cfb
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Showing 2 changed files with 14 additions and 3 deletions.
diff --git a/src/Perl6/Grammar.nqp b/src/Perl6/Grammar.nqp
@@ -2811,7 +2811,12 @@ grammar Perl6::Grammar is HLL::Grammar does STD {
         <post_constraint>*
         [
             <default_value>
-            [<!before <[,;)\]{}-]> > { self.typed_panic("X::Parameter::MisplacedDefault") }]?
+            [ <modifier=.trait> {
+                self.typed_panic: "X::Parameter::AfterDefault", type => "trait", modifier => $<modifier>, default => $<default_value>
+            }]?
+            [ <modifier=.post_constraint> {
+                self.typed_panic: "X::Parameter::AfterDefault", type => "post constraint", modifier => $<modifier>, default => $<default_value>
+            }]?
         ]**0..1
 
         # enforce zone constraints

diff --git a/src/core/Exception.pm b/src/core/Exception.pm
@@ -757,8 +757,14 @@ my class X::Parameter::Default does X::Comp {
     }
 }
 
-my class X::Parameter::MisplacedDefault does X::Syntax {
-    method message() { "Default expression must come last" }
+my class X::Parameter::AfterDefault does X::Syntax {
+    has $.type;
+    has $.modifier;
+    has $.default;
+    method message() {
+        "The $.type \"$.modifier\" came after the default value\n"
+        ~ "(did you mean \"...$.modifier $.default\"?)"
+    }
 }
 
 my class X::Parameter::Placeholder does X::Comp {