- Added SymbolSubstTypeMap.java

1 files changed, 147 insertions, 0 deletions

diff --git a/sources/scalac/symtab/SymbolSubstTypeMap.java b/sources/scalac/symtab/SymbolSubstTypeMap.java
new file mode 100644
index 0000000000..0ecbacc1d9
--- /dev/null
+++ b/sources/scalac/symtab/SymbolSubstTypeMap.java
@@ -0,0 +1,147 @@
+/*     ____ ____  ____ ____  ______                                     *\
+**    / __// __ \/ __// __ \/ ____/    SOcos COmpiles Scala             **
+**  __\_ \/ /_/ / /__/ /_/ /\_ \       (c) 2002, LAMP/EPFL              **
+** /_____/\____/\___/\____/____/                                        **
+\*                                                                      */
+
+// $Id$
+
+package scalac.symtab;
+
+import java.util.Iterator;
+import java.util.Map;
+import java.util.HashMap;
+import java.util.Set;
+
+import scalac.util.Debug;
+
+/** A type map that substitues symbols and types for symbols. */
+public class SymbolSubstTypeMap extends Type.Map {
+
+    //########################################################################
+    // Private Fields
+
+    /** A table containing the symbol to symbol substitutions */
+    private Map/*<Symbol, Symbol>*/ symbols;
+
+    /** A table containing the symbol to type substitutions */
+    private Map/*<Symbol, Type>*/ types;
+
+    //########################################################################
+    // Public Constructors
+
+    public SymbolSubstTypeMap() {
+        this.symbols = new HashMap();
+        this.types = new HashMap();
+    }
+
+    public SymbolSubstTypeMap(Map symbols, Map types) {
+        this();
+        insertSymbol(symbols);
+        insertType(symbols);
+    }
+
+    //########################################################################
+    // Public Methods - Inserting and removing symbol to symbol substitutions
+
+    public void insertSymbol(Symbol[] keys, Symbol[] values) {
+        assert keys.length == values.length : keys.length+" != "+values.length;
+        for (int i = 0; i < keys.length; i++) insertSymbol(keys[i], values[i]);
+    }
+
+    public void insertSymbol(Symbol key, Symbol value) {
+        assert !types.containsKey(key) : Debug.show(key);
+        symbols.put(key, value);
+    }
+
+    public void insertSymbol(Map map) {
+        assert checkLeftContainsNoKeyFromRight(types, map);
+        symbols.putAll(map);
+    }
+
+    public void removeSymbol(Symbol[] keys) {
+        for (int i = 0; i < keys.length; i++) removeSymbol(keys[i]);
+    }
+
+    public void removeSymbol(Symbol key) {
+        symbols.remove(key);
+    }
+
+    public void removeSymbol(Set keys) {
+        symbols.keySet().removeAll(keys);
+    }
+
+    //########################################################################
+    // Public Methods - Inserting and removing symbol to type substitutions
+
+    public void insertType(Symbol[] keys, Type[] values) {
+        assert keys.length == values.length : keys.length+" != "+values.length;
+        for (int i = 0; i < keys.length; i++) insertType(keys[i], values[i]);
+    }
+
+    public void insertType(Symbol key, Type value) {
+        assert !symbols.containsKey(key) : Debug.show(key);
+        types.put(key, value);
+    }
+
+    public void insertType(Map map) {
+        assert checkLeftContainsNoKeyFromRight(symbols, map);
+        types.putAll(map);
+    }
+
+    public void removeType(Symbol[] keys) {
+        for (int i = 0; i < keys.length; i++) removeType(keys[i]);
+    }
+
+    public void removeType(Symbol key) {
+        types.remove(key);
+    }
+
+    public void removeType(Set keys) {
+        types.keySet().removeAll(keys);
+    }
+
+    //########################################################################
+    // Public Methods - Applying the substitutions
+
+    public Type apply(Type type) {
+        switch (type) {
+
+        case TypeRef(ThisType(_), Symbol symbol, Type[] args): {
+            Object value = types.get(symbol);
+            if (value != null) return (Type)value;
+            value = symbols.get(symbol);
+            if (value == null) return super.map(type);
+            Type prefix = ((Type.TypeRef)type).pre;
+            return Type.typeRef(apply(prefix), (Symbol)value, map(args));
+        }
+
+        case SingleType(ThisType(_), Symbol symbol): {
+            Object value = types.get(symbol);
+            if (value != null) return (Type)value;
+            value = symbols.get(symbol);
+            if (value == null) return super.map(type);
+            Type prefix = ((Type.TypeRef)type).pre;
+            return Type.singleType(apply(prefix), (Symbol)value);
+        }
+
+            // TODO what should we do with PolyTypes?
+
+        default:
+            return super.map(type);
+        }
+    }
+
+    //########################################################################
+    // Private Function
+
+    private static boolean checkLeftContainsNoKeyFromRight(Map lf, Map rg) {
+        for (Iterator i = rg.keySet().iterator(); i.hasNext(); ) {
+            Object key = i.next();
+            assert !lf.containsKey(key) : Debug.show(key);
+        }
+        return true;
+    }
+
+    //########################################################################
+}