RakuAST hanlding of implicit $!, $/, and $_

At the compilation unit and routine level.
rakudo · Jul 7, 2020 · 55e15db · 55e15db
1 parent bd890a8
commit 55e15db
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Showing 3 changed files with 49 additions and 2 deletions.
diff --git a/src/Raku/ast/code.rakumod b/src/Raku/ast/code.rakumod
@@ -163,7 +163,8 @@ class RakuAST::PointyBlock is RakuAST::Block {
 
 # Done by all kinds of Routine.
 class RakuAST::Routine is RakuAST::LexicalScope is RakuAST::Term is RakuAST::Code is RakuAST::Meta
-                       is RakuAST::SinkBoundary is RakuAST::Declaration {
+                       is RakuAST::SinkBoundary is RakuAST::Declaration
+                       is RakuAST::ImplicitDeclarations {
     has RakuAST::Name $.name;
     has RakuAST::Signature $.signature;
     has RakuAST::Blockoid $.body;
@@ -201,6 +202,14 @@ class RakuAST::Routine is RakuAST::LexicalScope is RakuAST::Term is RakuAST::Cod
         $routine
     }
 
+    method PRODUCE-IMPLICIT-DECLARATIONS() {
+        self.IMPL-WRAP-LIST([
+            RakuAST::VarDeclaration::Implicit::Special.new(:name('$/')),
+            RakuAST::VarDeclaration::Implicit::Special.new(:name('$!')),
+            RakuAST::VarDeclaration::Implicit::Special.new(:name('$_')),
+        ])
+    }
+
     method IMPL-QAST-FORM-BLOCK(RakuAST::IMPL::QASTContext $context) {
         # TODO return handler
         my $block := QAST::Block.new(

diff --git a/src/Raku/ast/compunit.rakumod b/src/Raku/ast/compunit.rakumod
@@ -69,6 +69,9 @@ class RakuAST::CompUnit is RakuAST::LexicalScope is RakuAST::SinkBoundary
             nqp::push(@decls, RakuAST::VarDeclaration::Implicit::Constant.new(
                 name => '$?PACKAGE', value => $global.compile-time-value
             ));
+            nqp::push(@decls, RakuAST::VarDeclaration::Implicit::Special.new(:name('$/')));
+            nqp::push(@decls, RakuAST::VarDeclaration::Implicit::Special.new(:name('$!')));
+            nqp::push(@decls, RakuAST::VarDeclaration::Implicit::Special.new(:name('$_')));
         }
         self.IMPL-WRAP-LIST(@decls)
     }

diff --git a/src/Raku/ast/variable-declaration.rakumod b/src/Raku/ast/variable-declaration.rakumod
@@ -295,7 +295,7 @@ class RakuAST::VarDeclaration::Simple is RakuAST::Declaration is RakuAST::Implic
     }
 }
 
-# An implicitly declared variable. Typically used for $/, $!, and $_.
+# The commonalities for implicitly declared variables.
 class RakuAST::VarDeclaration::Implicit is RakuAST::Declaration {
     has str $.name;
 
@@ -314,6 +314,12 @@ class RakuAST::VarDeclaration::Implicit is RakuAST::Declaration {
         'my'
     }
 
+    method generate-lookup() {
+        my $lookup := RakuAST::Var::Lexical.new($!name);
+        $lookup.set-resolution(self);
+        $lookup
+    }
+
     method IMPL-TO-QAST(RakuAST::IMPL::QASTContext $context) {
         self.IMPL-LOOKUP-QAST($context)
     }
@@ -323,6 +329,35 @@ class RakuAST::VarDeclaration::Implicit is RakuAST::Declaration {
     }
 }
 
+# An implicitly declared special variable. Typically used for $/, $!, and $_.
+class RakuAST::VarDeclaration::Implicit::Special is RakuAST::VarDeclaration::Implicit
+                                                 is RakuAST::Meta {
+    method PRODUCE-META-OBJECT() {
+        # Reuse the container descriptor for the common cases that we expect
+        # to have.
+        my constant COMMON := nqp::hash(
+            '$_', ContainerDescriptor.new(:of(Mu), :default(Any), :!dynamic, :name('$_')),
+            '$/', ContainerDescriptor.new(:of(Mu), :default(Any), :dynamic, :name('$/')),
+            '$!', ContainerDescriptor.new(:of(Mu), :default(Any), :dynamic, :name('$!'))
+        );
+        my $cont-desc := COMMON{self.name} //
+            ContainerDescriptor.new(:of(Mu), :default(Any), :!dynamic, :name(self.name));
+        my $container := nqp::create(Scalar);
+        nqp::bindattr($container, Scalar, '$!descriptor', $cont-desc);
+        nqp::bindattr($container, Scalar, '$!value', Any);
+        $container
+    }
+
+    method IMPL-QAST-DECL(RakuAST::IMPL::QASTContext $context) {
+        my $container := self.meta-object;
+        $context.ensure-sc($container);
+        QAST::Var.new(
+            :scope('lexical'), :decl('contvar'), :name(self.name),
+            :value($container)
+        )
+    }
+}
+
 # An implicitly declared constant variable - that is, one with a value that is
 # fixed at compile time. Used for $?PACKAGE and similar.
 class RakuAST::VarDeclaration::Implicit::Constant is RakuAST::VarDeclaration::Implicit