implement labels for while loops

This allows the declaration of labels for all statements, and adds next/redo/last LABEL functionality for while loops.
Raku · Nov 24, 2013 · 3203a9f · 3203a9f
1 parent 2339be2
commit 3203a9f
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Showing 3 changed files with 44 additions and 10 deletions.
diff --git a/src/NQP/Actions.nqp b/src/NQP/Actions.nqp
@@ -290,7 +290,10 @@ class NQP::Actions is HLL::Actions {
     method statement_control:sym<while>($/) {
         my $past := xblock_immediate( $<xblock>.ast );
         $past.op(~$<sym>);
-        unless $*CONTROL_USED {
+        if $*LABEL {
+            $past.push(QAST::WVal.new( :value($*W.find_sym([$*LABEL])), :named('label') ));
+        }
+        elsif !$*CONTROL_USED {
             $past.push(QAST::IVal.new( :value(1), :named('nohandler') ));
         }
         make $past;
@@ -1574,9 +1577,33 @@ class NQP::Actions is HLL::Actions {
         );
     }
 
-    method term:sym<next>($/) { make QAST::Op.new( :op('control'), :name('next') ) }
-    method term:sym<last>($/) { make QAST::Op.new( :op('control'), :name('last') ) }
-    method term:sym<redo>($/) { make QAST::Op.new( :op('control'), :name('redo') ) }
+    method term:sym<next>($/) {
+        my $ast := QAST::Op.new( :op('control'), :name('next') );
+
+        if $<identifier> {
+            $ast.push(QAST::WVal.new( :value($*W.find_sym([$<identifier>])), :named('label') ));
+        }
+
+        make $ast
+    }
+    method term:sym<last>($/) {
+        my $ast := QAST::Op.new( :op('control'), :name('last') );
+
+        if $<identifier> {
+            $ast.push(QAST::WVal.new( :value($*W.find_sym([$<identifier>])), :named('label') ));
+        }
+
+        make $ast
+    }
+    method term:sym<redo>($/) {
+        my $ast := QAST::Op.new( :op('control'), :name('redo') );
+
+        if $<identifier> {
+            $ast.push(QAST::WVal.new( :value($*W.find_sym([$<identifier>])), :named('label') ));
+        }
+
+        make $ast
+    }
 
     method infix:sym<~~>($/) {
         make QAST::Op.new( :op<callmethod>, :name<ACCEPTS>, :node($/) );

diff --git a/src/NQP/Grammar.nqp b/src/NQP/Grammar.nqp
@@ -152,14 +152,19 @@ grammar NQP::Grammar is HLL::Grammar {
     }
 
     token label {
-        :my $label;
         <identifier> ':' <?[\s]> <.ws>
+        {
+            $*LABEL := ~$<identifier>;
+            my $label := $*W.find_sym(['NQPLabel']).new();
+            $*W.add_object($label);
+            $*W.install_lexical_symbol($*W.cur_lexpad(), $*LABEL, $label);
+        }
     }
 
-    token statement {
+    token statement($*LABEL = '') {
         <!before <[\])}]> | $ >
         [
-        | <label> <statement>
+        | <label> <statement($*LABEL)> { $*LABEL := '' if $*LABEL }
         | <statement_control>
         | <EXPR> <.ws>
             [
@@ -311,9 +316,9 @@ grammar NQP::Grammar is HLL::Grammar {
     token term:sym<regex_declarator>   { <regex_declarator> }
     token term:sym<statement_prefix>   { <statement_prefix> }
     token term:sym<lambda>             { <?lambda> <pblock> }
-    token term:sym<last>               { <sym> <!identifier> { $*CONTROL_USED := 1 } }
-    token term:sym<next>               { <sym> <!identifier> { $*CONTROL_USED := 1 } }
-    token term:sym<redo>               { <sym> <!identifier> { $*CONTROL_USED := 1 } }
+    token term:sym<last>               { <sym> [<.ws> <identifier> <?{ $*W.is_lexical(~$<identifier>) }>]? { $*CONTROL_USED := 1 } }
+    token term:sym<next>               { <sym> [<.ws> <identifier> <?{ $*W.is_lexical(~$<identifier>) }>]? { $*CONTROL_USED := 1 } }
+    token term:sym<redo>               { <sym> [<.ws> <identifier> <?{ $*W.is_lexical(~$<identifier>) }>]? { $*CONTROL_USED := 1 } }
 
     token fatarrow {
         <key=.identifier> \h* '=>' <.ws> <val=.EXPR('i=')>

diff --git a/src/core/NQPMu.nqp b/src/core/NQPMu.nqp
@@ -134,3 +134,5 @@ nqp::sethllconfig('nqp', nqp::hash(
     'hash_iter', NQPHashIter
 ));
 #?endif
+
+my class NQPLabel { }