[examples/rubyish] added "undeclared variable" error message

Author: dwarring

examples/rubyish/rubyish.nqp

@@ -57,8 +57,9 @@ grammar Rubyish::Grammar is HLL::Grammar {
         :my $*CLASS_BLOCK := $*CUR_BLOCK;
         :my $*IN_TEMPLATE := 0;
         :my $*IN_PARENS   := 0;
-        :my %*SYM;
-        :my %*CLASS_SYMS;
+        :my %*SYM;                # symbols in current scope
+        :my %*SYM-GBL;            # globals and package variables
+        :my %*SYM-CLASS;          # class-inherited methods
 
         ^ ~ $ <stmtlist>
             || <.panic('Syntax error')>
@@ -93,7 +94,13 @@ grammar Rubyish::Grammar is HLL::Grammar {
         :my $*CUR_BLOCK := QAST::Block.new(QAST::Stmts.new());
         <operation> {
             $*DEF := ~$<operation>;
-            %*SYM{$*DEF} := $*IN_CLASS ?? 'method' !! 'func';
+            if $*IN_CLASS {
+                %*SYM{$*DEF} := 'method';
+                %*SYM<self> := 'var';
+            }
+            else {
+                %*SYM{$*DEF} := 'func';
+            }
         }
         ['(' ~ ')' <signature>?]? <separator>?
         <stmtlist>
@@ -130,7 +137,7 @@ grammar Rubyish::Grammar is HLL::Grammar {
         [ '<' <super=.ident> { inherit-syms(~$<super>) } ]?
         <separator>
         <stmtlist> {
-            %*CLASS_SYMS{~$<ident>} := %*SYM;
+            %*SYM-CLASS{~$<ident>} := %*SYM;
         }
     }
 
@@ -203,9 +210,12 @@ grammar Rubyish::Grammar is HLL::Grammar {
     token var {
         :my $*MAYBE_DECL := 0;
         \+?
-        [$<sigil>=[ \$ | \@ ] | <pkg=.ident>'::'<?before <[A..Z]>> | <!keyword> ]
-        <ident><!before [\!|\?|<hs>\(]>
-        [ <?before <hs> <bind-op> { $*MAYBE_DECL := 1 }> || <?> ]
+        $<var>=[[$<sigil>=[ \$ | \@ ] | <pkg=.ident>'::'<?before <[A..Z]>> | <!keyword> ] <ident>]
+        <!before [\!|\?|<hs>\(]>
+        [  <?before <hs> <bind-op> { $*MAYBE_DECL := 1 }>
+        || <?{ variable(~$<var>) || ~$<sigil> eq '@' }>
+        || <!{ callable(~$<var>) }> <.panic("undeclared variable: $<var>")>
+        ]
     }
 
     token term:sym<var>   { <var> }
@@ -445,13 +455,19 @@ grammar Rubyish::Grammar is HLL::Grammar {
 
     # Functions
     sub callable($op) {
-       my $type := %*SYM{$op} || (%builtins{$op} && 'func');
+       my $type := %*SYM{$op} // (%builtins{$op} && 'func');
 
        $type && ($type eq 'func' || $type eq 'method');
     }
 
+    sub variable($op) {
+       my $type := %*SYM{$op} // %*SYM-GBL{$op};
+
+       $type && ($type eq 'var');
+    }
+
     sub inherit-syms($class) {
-        if my %syms := %*CLASS_SYMS{$class} {
+        if my %syms := %*SYM-CLASS{$class} {
             %*SYM{$_} := %syms{$_}
                 for %syms;
         }
@@ -579,8 +595,6 @@ class Rubyish::Actions is HLL::Actions {
         make $<call-args>.ast;
     }
 
-    my $tmpsym := 0;
-
     method term:sym<new>($/) {
 
         my $tmp-obj := '$new-obj$';
@@ -672,6 +686,9 @@ class Rubyish::Actions is HLL::Actions {
 
                 if $sigil eq '$' || $ns {
                     $block := $*TOP_BLOCK;
+                    %*SYM-GBL{$name} := 'var';
+                    %*SYM{~$<ident>} := 'var'
+                        if $ns;
                 }
                 elsif !$sigil {
                     $block := $*CUR_BLOCK;

examples/rubyish/t/scoping.t

@@ -21,6 +21,7 @@ class DerivedClass < BaseClass
 end
 
 class DisjointClass
+  Y = 42;
   def set_inst1(v); @i1 = v;             end
   def set_inst2(v); @i2 = v;             end
   def get_inst1; @i1;                    end