RakuAST: detect a case of double closure

Detects {* + 1}(1) which is {{$_ + 1}}(1) which won't do what's intended.
rakudo · May 2, 2024 · 331f019 · 331f019
1 parent 4988fb3
commit 331f019
Showing 1 changed file with 20 additions and 0 deletions.
diff --git a/src/Raku/ast/expressions.rakumod b/src/Raku/ast/expressions.rakumod
@@ -2466,6 +2466,7 @@ class RakuAST::MetaPostfix::Hyper
 class RakuAST::ApplyPostfix
   is RakuAST::Termish
   is RakuAST::BeginTime
+  is RakuAST::CheckTime
   is RakuAST::WhateverApplicable
 {
     has RakuAST::Postfixish $.postfix;
@@ -2532,6 +2533,25 @@ class RakuAST::ApplyPostfix
         }
     }
 
+    method PERFORM-CHECK(Resolver $resolver, RakuAST::IMPL::QASTContext $context) {
+        #  ApplyPostfix  ⎡(...)⎤
+        #    Block  ⎡{*.{}}⎤
+        #      Blockoid 𝄞 -e:1 ⎡{*.{}}⎤
+        #        StatementList 𝄞 -e:1 ⎡*.{}⎤
+        #          Statement::Expression ▪𝄞 -e:1 ⎡*.{}⎤
+        #            ... [curried]
+        #    Call::Term  ⎡(...)⎤
+        #      ArgList  ⎡...⎤
+        if nqp::istype($!operand, RakuAST::Block) && nqp::istype($!postfix, RakuAST::Call::Term) {
+            my $stmts := $!operand.body.statement-list;
+            if $stmts.IMPL-IS-SINGLE-EXPRESSION && $stmts.code-statements[0].expression.IMPL-CURRIED {
+                self.add-sorry:
+                    $resolver.build-exception: 'X::Syntax::Malformed',
+                        :what('double closure; WhateverCode is already a closure without curlies, so either remove the curlies or use valid parameter syntax instead of *')
+            }
+        }
+    }
+
     method IMPL-EXPR-QAST(RakuAST::IMPL::QASTContext $context) {
         my $postfix-ast := $!postfix.IMPL-POSTFIX-QAST($context, $!operand.IMPL-TO-QAST($context));
         # Method calls may be to a foreign language, and thus return