collect variables from patterns

2 files changed, 96 insertions, 0 deletions

diff --git a/sources/scalac/transformer/matching/CollectVariableTraverser.java b/sources/scalac/transformer/matching/CollectVariableTraverser.java
new file mode 100644
index 0000000000..5223bdee46
--- /dev/null
+++ b/sources/scalac/transformer/matching/CollectVariableTraverser.java
@@ -0,0 +1,35 @@
+package scalac.transformer.matching ;
+
+import scalac.util.Name ;
+import scalac.ast.Tree ;
+import scalac.symtab.Symbol ;
+
+import java.util.Vector;
+
+class CollectVariableTraverser extends VariableTraverser {
+
+      Vector vars;
+
+      boolean isVariableName( Name name ) {
+            return ( name.toString().indexOf("$") == -1 )
+                  && super.isVariableName( name );
+      }
+
+
+      void handleVariableSymbol( Symbol sym ) {
+            vars.add( sym );
+      }
+
+      public CollectVariableTraverser() {
+            this.vars = new Vector();
+      }
+
+      static  boolean containsBinding( Tree  pat ) {
+
+            CollectVariableTraverser cvt = new CollectVariableTraverser();
+            cvt.traverse( pat );
+            return !cvt.vars.isEmpty();
+
+      }
+
+}
diff --git a/sources/scalac/transformer/matching/VariableTraverser.java b/sources/scalac/transformer/matching/VariableTraverser.java
new file mode 100644
index 0000000000..d03e2a05e2
--- /dev/null
+++ b/sources/scalac/transformer/matching/VariableTraverser.java
@@ -0,0 +1,61 @@
+package scalac.transformer.matching ;
+
+
+import scalac.ast.Tree;
+import scalac.util.Name;
+import scalac.symtab.Symbol ;
+import scalac.ast.Traverser ;
+
+import Tree.Ident;
+import Tree.Bind;
+
+
+abstract class VariableTraverser extends Traverser {
+
+      boolean isVariableName( Name name ) {
+            return ( name.isVariable() ) && ( name != Name.fromString("_") ) ;
+
+      }
+
+      boolean isVariableSymbol( Symbol sym ) {
+            return ( sym != null )&&( !sym.isPrimaryConstructor() );
+      }
+
+      abstract void handleVariableSymbol( Symbol sym ) ;
+
+      public VariableTraverser() {
+            super();
+      }
+
+
+      public void traverse(Tree tree) {
+            switch (tree) {
+            case Ident(Name name):
+                  Symbol sym;
+
+                  if( isVariableName( name )
+                      && isVariableSymbol( sym = tree.symbol() ) )
+                        handleVariableSymbol( sym );
+
+                  return;
+
+            case Bind(Name name, Tree subtree):
+                  Symbol sym;
+
+                  if( isVariableName( name )
+                      && isVariableSymbol( sym = tree.symbol() ))
+                        handleVariableSymbol( sym );
+
+                  traverse( subtree );
+
+                  return;
+
+            case Select(_,_):
+                  return;
+            default:
+                  super.traverse( tree );
+            }
+      }
+
+
+}