Add some new classes/enums/delegates for 2.0 and some new CAS unit tests
[mono.git] / mcs / mcs / constant.cs
old mode 100755 (executable)
new mode 100644 (file)
index b97972b..18ca2dd
-namespace CIR {
+//
+// constant.cs: Constants.
+//
+// Author:
+//   Miguel de Icaza (miguel@ximian.com)
+//   Marek Safar (marek.safar@seznam.cz)
+//
+// (C) 2001 Ximian, Inc.
+//
+//
+
+namespace Mono.CSharp {
 
        using System;
-       using System.Reflection;
        using System.Reflection.Emit;
+
+       /// <summary>
+       ///   Base class for constants and literals.
+       /// </summary>
+       public abstract class Constant : Expression {
+
+               protected Constant (Location loc)
+               {
+                       this.loc = loc;
+               }
+
+               /// <remarks>
+               ///   This is different from ToString in that ToString
+               ///   is supposed to be there for debugging purposes,
+               ///   and is not guaranteed to be useful for anything else,
+               ///   AsString() will provide something that can be used
+               ///   for round-tripping C# code.  Maybe it can be used
+               ///   for IL assembly as well.
+               /// </remarks>
+               public abstract string AsString ();
+
+               override public string ToString ()
+               {
+                       return this.GetType ().Name + " (" + AsString () + ")";
+               }
+
+               /// <summary>
+               ///  This is used to obtain the actual value of the literal
+               ///  cast into an object.
+               /// </summary>
+               public abstract object GetValue ();
+
+               public virtual object GetTypedValue ()
+               {
+                       return GetValue ();
+               }
+
+               /// <summary>
+               ///   Constants are always born in a fully resolved state
+               /// </summary>
+               public override Expression DoResolve (EmitContext ec)
+               {
+                       return this;
+               }
+
+               //
+               // The various ToXXXX conversion functions are used by the constant
+               // folding evaluator.   A null value is returned if the conversion is
+               // not possible.   
+               //
+               // Note: not all the patterns for catching `implicit_conv' are the same.
+               // some implicit conversions can never be performed between two types
+               // even if the conversion would be lossless (for example short to uint),
+               // but some conversions are explicitly permitted by the standard provided
+               // that there will be no loss of information (for example, int to uint).
+               //
+               public DoubleConstant ToDouble (Location loc)
+               {
+                       DoubleConstant c = ConvertToDouble ();
+
+                       if (c == null)
+                               Error_ValueCannotBeConverted (loc, TypeManager.double_type, false);
+
+                       return c;
+               }
+
+               public FloatConstant ToFloat (Location loc)
+               {
+                       FloatConstant c = ConvertToFloat ();
+
+                       if (c == null)
+                               Error_ValueCannotBeConverted (loc, TypeManager.float_type, false);
+
+                       return c;
+               }
+
+               public ULongConstant ToULong (Location loc)
+               {
+                       ULongConstant c = ConvertToULong ();
+
+                       if (c == null)
+                               Error_ValueCannotBeConverted (loc, TypeManager.uint64_type, false);
+
+                       return c;
+               }
+
+               public LongConstant ToLong (Location loc)
+               {
+                       LongConstant c = ConvertToLong ();
+
+                       if (c == null)
+                               Error_ValueCannotBeConverted (loc, TypeManager.int64_type, false);
+
+                       return c;
+               }
+               
+               public UIntConstant ToUInt (Location loc)
+               {
+                       UIntConstant c = ConvertToUInt ();
+
+                       if (c == null)
+                               Error_ValueCannotBeConverted (loc, TypeManager.uint32_type, false);
+
+                       return c;
+               }
+
+               public IntConstant ToInt (Location loc)
+               {
+                       IntConstant c = ConvertToInt ();
+
+                       if (c == null)
+                               Error_ValueCannotBeConverted (loc, TypeManager.int32_type, false);
+
+                       return c;
+               }
+
+               public DecimalConstant ToDecimal (Location loc)
+               {
+                       DecimalConstant c = ConvertToDecimal ();
+
+                       if (c == null)
+                               Error_ValueCannotBeConverted (loc, TypeManager.decimal_type, false);
+
+                       return c;
+               }
+
+               public virtual Constant ToType (Type type, Location loc)
+               {
+                       if (Type == type)
+                               return this;
+
+                       if (type == TypeManager.object_type)
+                               return this;
+
+                       if (!Convert.ImplicitStandardConversionExists (Convert.ConstantEC, this, type)){
+                               Error_ValueCannotBeConverted (loc, type, false);
+                               return null;
+                       }
+
+                       // Special-case: The 0 literal can be converted to an enum value,
+                       // and ImplicitStandardConversionExists will return true in that case.
+                       if (IsZeroInteger && Type == TypeManager.int32_type && TypeManager.IsEnumType (type)) {
+                               return new EnumConstant (this, type);
+                       }
+
+                       bool fail;                      
+                       object constant_value = TypeManager.ChangeType (GetValue (), type, out fail);
+                       if (fail){
+                               Error_ValueCannotBeConverted (loc, type, false);
+                               
+                               //
+                               // We should always catch the error before this is ever
+                               // reached, by calling Convert.ImplicitStandardConversionExists
+                               //
+                               throw new Exception (
+                                       String.Format ("LookupConstantValue: This should never be reached {0} {1}", Type, type));
+                       }
+
+                       Constant retval;
+                       if (type == TypeManager.int32_type)
+                               retval = new IntConstant ((int) constant_value, loc);
+                       else if (type == TypeManager.uint32_type)
+                               retval = new UIntConstant ((uint) constant_value, loc);
+                       else if (type == TypeManager.int64_type)
+                               retval = new LongConstant ((long) constant_value, loc);
+                       else if (type == TypeManager.uint64_type)
+                               retval = new ULongConstant ((ulong) constant_value, loc);
+                       else if (type == TypeManager.float_type)
+                               retval = new FloatConstant ((float) constant_value, loc);
+                       else if (type == TypeManager.double_type)
+                               retval = new DoubleConstant ((double) constant_value, loc);
+                       else if (type == TypeManager.string_type)
+                               retval = new StringConstant ((string) constant_value, loc);
+                       else if (type == TypeManager.short_type)
+                               retval = new ShortConstant ((short) constant_value, loc);
+                       else if (type == TypeManager.ushort_type)
+                               retval = new UShortConstant ((ushort) constant_value, loc);
+                       else if (type == TypeManager.sbyte_type)
+                               retval = new SByteConstant ((sbyte) constant_value, loc);
+                       else if (type == TypeManager.byte_type)
+                               retval = new ByteConstant ((byte) constant_value, loc);
+                       else if (type == TypeManager.char_type)
+                               retval = new CharConstant ((char) constant_value, loc);
+                       else if (type == TypeManager.bool_type)
+                               retval = new BoolConstant ((bool) constant_value, loc);
+                       else if (type == TypeManager.decimal_type)
+                               retval = new DecimalConstant ((decimal) constant_value, loc);
+                       else
+                               throw new Exception ("LookupConstantValue: Unhandled constant type: " + type);
+                       
+                       return retval;
+               }
+
+               protected void CheckRange (EmitContext ec, ulong value, Type type, ulong max)
+               {
+                       if (!ec.ConstantCheckState)
+                               return;
+
+                       if (value > max)
+                               throw new OverflowException ();
+               }
+
+               protected void CheckRange (EmitContext ec, double value, Type type, long min, long max)
+               {
+                       if (!ec.ConstantCheckState)
+                               return;
+
+                       if (((value < min) || (value > max)))
+                               throw new OverflowException ();
+               }
+
+               protected void CheckUnsigned (EmitContext ec, long value, Type type)
+               {
+                       if (!ec.ConstantCheckState)
+                               return;
+
+                       if (value < 0)
+                               throw new OverflowException ();
+               }
+
+               public abstract Constant Reduce (EmitContext ec, Type target_type);
+
+               /// <summary>
+               ///   Attempts to do a compile-time folding of a constant cast.
+               /// </summary>
+               public Constant TryReduce (EmitContext ec, Type target_type, Location loc)
+               {
+                       try {
+                               return  TryReduce (ec, target_type);
+                       }
+                       catch (OverflowException) {
+                               if (ec.ConstantCheckState) {
+                                       Report.Error (221, loc, "Constant value `{0}' cannot be converted to a `{1}' (use `unchecked' syntax to override)",
+                                               this.GetValue (), TypeManager.CSharpName (target_type));
+                               }
+                               return null;
+                       }
+               }
+
+               Constant TryReduce (EmitContext ec, Type target_type)
+               {
+                       if (Type == target_type)
+                               return this;
+
+                       if (TypeManager.IsEnumType (target_type)) {
+                               Constant c = TryReduce (ec, TypeManager.EnumToUnderlying (target_type));
+                               if (c == null)
+                                       return null;
+
+                               return new EnumConstant (c, target_type);
+                       }
+
+                       return Reduce (ec, target_type);
+               }
+
+
+               public virtual DecimalConstant ConvertToDecimal ()
+               {
+                       return null;
+               }
+               
+               public virtual DoubleConstant ConvertToDouble ()
+               {
+                       return null;
+               }
+
+               public virtual FloatConstant ConvertToFloat ()
+               {
+                       return null;
+               }
+
+               public virtual ULongConstant ConvertToULong ()
+               {
+                       return null;
+               }
+
+               public virtual LongConstant ConvertToLong ()
+               {
+                       return null;
+               }
+
+               public virtual UIntConstant ConvertToUInt ()
+               {
+                       return null;
+               }
+
+               public virtual IntConstant ConvertToInt ()
+               {
+                       return null;
+               }
+
+               public abstract Constant Increment ();
+               
+               public abstract bool IsDefaultValue {
+                       get;
+               }
+
+               public abstract bool IsNegative {
+                       get;
+               }
+
+               //
+               // Returns true iff 1) the stack type of this is one of Object, 
+               // int32, int64 and 2) this == 0 or this == null.
+               //
+               public virtual bool IsZeroInteger {
+                       get { return false; }
+               }
+       }
        
-       public class Constant : Expression {
-               string     name;
-               Expression expr;
-               string     constant_type;
-               int        mod_flags;
+       public class BoolConstant : Constant {
+               public readonly bool Value;
+               
+               public BoolConstant (bool val, Location loc):
+                       base (loc)
+               {
+                       type = TypeManager.bool_type;
+                       eclass = ExprClass.Value;
 
-               public const int AllowedModifiers =
-                       Modifiers.NEW |
-                       Modifiers.PUBLIC |
-                       Modifiers.PROTECTED |
-                       Modifiers.INTERNAL |
-                       Modifiers.PRIVATE;
+                       Value = val;
+               }
+
+               override public string AsString ()
+               {
+                       return Value ? "true" : "false";
+               }
 
-               public Constant (string constant_type, string name, Expression expr, int mod_flags)
+               public override object GetValue ()
+               {
+                       return (object) Value;
+               }
+                               
+               
+               public override void Emit (EmitContext ec)
                {
-                       this.constant_type = constant_type;
-                       this.name = name;
-                       this.expr = expr;
-                       this.mod_flags = Modifiers.Check (AllowedModifiers, mod_flags, Modifiers.PRIVATE);
+                       if (Value)
+                               ec.ig.Emit (OpCodes.Ldc_I4_1);
+                       else
+                               ec.ig.Emit (OpCodes.Ldc_I4_0);
                }
 
-               public string Name {
+               public override Constant Increment ()
+               {
+                       throw new NotSupportedException ();
+               }
+       
+               public override bool IsDefaultValue {
                        get {
-                               return name;
+                               return !Value;
                        }
                }
 
-               public string ConstantType {
+               public override bool IsNegative {
                        get {
-                               return constant_type;
+                               return false;
                        }
                }
+       
+               public override bool IsZeroInteger {
+                       get { return Value == false; }
+               }
+
+               public override Constant Reduce (EmitContext ec, Type target_type)
+               {
+                       return null;
+               }
+
+       }
+
+       public class ByteConstant : Constant {
+               public readonly byte Value;
+
+               public ByteConstant (byte v, Location loc):
+                       base (loc)
+               {
+                       type = TypeManager.byte_type;
+                       eclass = ExprClass.Value;
+                       Value = v;
+               }
+
+               public override void Emit (EmitContext ec)
+               {
+                       IntLiteral.EmitInt (ec.ig, Value);
+               }
+
+               public override string AsString ()
+               {
+                       return Value.ToString ();
+               }
+
+               public override object GetValue ()
+               {
+                       return Value;
+               }
+
+               public override DoubleConstant ConvertToDouble ()
+               {
+                       return new DoubleConstant (Value, loc);
+               }
+
+               public override FloatConstant ConvertToFloat ()
+               {
+                       return new FloatConstant (Value, loc);
+               }
+
+               public override ULongConstant ConvertToULong ()
+               {
+                       return new ULongConstant (Value, loc);
+               }
+
+               public override LongConstant ConvertToLong ()
+               {
+                       return new LongConstant (Value, loc);
+               }
+
+               public override UIntConstant ConvertToUInt ()
+               {
+                       return new UIntConstant (Value, loc);
+               }
+
+               public override IntConstant ConvertToInt ()
+               {
+                       return new IntConstant (Value, loc);
+               }
+
+               public override Constant Increment ()
+               {
+                       return new ByteConstant (checked ((byte)(Value + 1)), loc);
+               }
 
-               public Expression Expr {
+               public override bool IsDefaultValue {
                        get {
-                               return expr;
+                               return Value == 0;
                        }
                }
 
-               public FieldAttributes FieldAttr {
+               public override bool IsNegative {
                        get {
-                               return FieldAttributes.Literal | Modifiers.FieldAttr (mod_flags) ;
+                               return false;
+                       }
+               }
+
+               public override bool IsZeroInteger {
+                       get { return Value == 0; }
+               }
+
+               public override Constant Reduce (EmitContext ec, Type target_type)
+               {
+                       if (target_type == TypeManager.sbyte_type) {
+                               CheckRange (ec, Value, target_type, SByte.MinValue, SByte.MaxValue);
+                               return new SByteConstant ((sbyte) Value, Location);
                        }
+                       if (target_type == TypeManager.short_type)
+                               return new ShortConstant ((short) Value, Location);
+                       if (target_type == TypeManager.ushort_type)
+                               return new UShortConstant ((ushort) Value, Location);
+                       if (target_type == TypeManager.int32_type)
+                               return new IntConstant ((int) Value, Location);
+                       if (target_type == TypeManager.uint32_type)
+                               return new UIntConstant ((uint) Value, Location);
+                       if (target_type == TypeManager.int64_type)
+                               return new LongConstant ((long) Value, Location);
+                       if (target_type == TypeManager.uint64_type)
+                               return new ULongConstant ((ulong) Value, Location);
+                       if (target_type == TypeManager.float_type)
+                               return new FloatConstant ((float) Value, Location);
+                       if (target_type == TypeManager.double_type)
+                               return new DoubleConstant ((double) Value, Location);
+                       if (target_type == TypeManager.char_type)
+                               return new CharConstant ((char) Value, Location);
+                       if (target_type == TypeManager.decimal_type)
+                               return new DecimalConstant ((decimal) Value, Location);
+
+                       return null;
                }
 
-               public override void Resolve (TypeContainer tc)
+       }
+
+       public class CharConstant : Constant {
+               public readonly char Value;
+
+               public CharConstant (char v, Location loc):
+                       base (loc)
                {
+                       type = TypeManager.char_type;
+                       eclass = ExprClass.Value;
+                       Value = v;
                }
 
                public override void Emit (EmitContext ec)
                {
+                       IntLiteral.EmitInt (ec.ig, Value);
                }
-                      
-               // <summary>
-               //   Defines the constant in the @parent
-               // </summary>
-               public void EmitConstant (RootContext rc, TypeContainer parent)
+
+               static public string descape (char c)
                {
-                       FieldBuilder fb;
-                       TypeCode tc;
-                       Type t;
-                       
-                       t = rc.LookupType (parent, constant_type);
-                       if (t == null)
-                               return;
+                       switch (c){
+                       case '\a':
+                               return "\\a"; 
+                       case '\b':
+                               return "\\b"; 
+                       case '\n':
+                               return "\\n"; 
+                       case '\t':
+                               return "\\t"; 
+                       case '\v':
+                               return "\\v"; 
+                       case '\r':
+                               return "\\r"; 
+                       case '\\':
+                               return "\\\\";
+                       case '\f':
+                               return "\\f"; 
+                       case '\0':
+                               return "\\0"; 
+                       case '"':
+                               return "\\\""; 
+                       case '\'':
+                               return "\\\'"; 
+                       }
+                       return c.ToString ();
+               }
 
-                       tc = System.Type.GetTypeCode (t);
-                       
-                       if ((tc == TypeCode.SByte)  || (tc == TypeCode.Byte)   ||
-                           (tc == TypeCode.Int16)  || (tc == TypeCode.UInt16) ||
-                           (tc == TypeCode.Int32)  || (tc == TypeCode.Int64)  ||
-                           (tc == TypeCode.UInt32) || (tc == TypeCode.UInt64)) {
-                               
-                       } else if ((tc == TypeCode.Double) || (tc == TypeCode.Single)) {
+               public override string AsString ()
+               {
+                       return "\"" + descape (Value) + "\"";
+               }
 
-                       } else if (tc == TypeCode.Char) {
-                       } else if (tc == TypeCode.Decimal) {
+               public override object GetValue ()
+               {
+                       return Value;
+               }
 
-                       } else if (t.IsSubclassOf (typeof (System.String))) {
+               public override DoubleConstant ConvertToDouble ()
+               {
+                       return new DoubleConstant (Value, loc);
+               }
 
-                       } else if (t.IsSubclassOf (typeof (System.Enum))) {
+               public override FloatConstant ConvertToFloat ()
+               {
+                       return new FloatConstant (Value, loc);
+               }
 
-                       } else {
-                               rc.Report.Error (-3, "Constant type is not valid (only system types are allowed");
-                               return;
+               public override ULongConstant ConvertToULong ()
+               {
+                       return new ULongConstant (Value, loc);
+               }
+
+               public override LongConstant ConvertToLong ()
+               {
+                       return new LongConstant (Value, loc);
+               }
+
+               public override UIntConstant ConvertToUInt ()
+               {
+                       return new UIntConstant (Value, loc);
+               }
+
+               public override IntConstant ConvertToInt ()
+               {
+                       return new IntConstant (Value, loc);
+               }
+
+               public override Constant Increment ()
+               {
+                       return new CharConstant (checked ((char)(Value + 1)), loc);
+               }
+               
+               public override bool IsDefaultValue {
+                       get {
+                               return Value == 0;
+                       }
+               }
+
+               public override bool IsNegative {
+                       get {
+                               return false;
                        }
+               }
 
-                       fb = parent.TypeBuilder.DefineField (name, t, FieldAttr);
-                       
+               public override bool IsZeroInteger {
+                       get { return Value == '\0'; }
+               }
+
+               public override Constant Reduce (EmitContext ec, Type target_type)
+               {
+                       if (target_type == TypeManager.byte_type) {
+                               CheckRange (ec, Value, target_type, Byte.MinValue, Byte.MaxValue);
+                               return new ByteConstant ((byte) Value, Location);
+                       }
+                       if (target_type == TypeManager.sbyte_type) {
+                               CheckRange (ec, Value, target_type, SByte.MinValue, SByte.MaxValue);
+                               return new SByteConstant ((sbyte) Value, Location);
+                       }
+                       if (target_type == TypeManager.short_type) {
+                               CheckRange (ec, Value, target_type, Int16.MinValue, Int16.MaxValue);
+                               return new ShortConstant ((short) Value, Location);
+                       }
+                       if (target_type == TypeManager.int32_type)
+                               return new IntConstant ((int) Value, Location);
+                       if (target_type == TypeManager.uint32_type)
+                               return new UIntConstant ((uint) Value, Location);
+                       if (target_type == TypeManager.int64_type)
+                               return new LongConstant ((long) Value, Location);
+                       if (target_type == TypeManager.uint64_type)
+                               return new ULongConstant ((ulong) Value, Location);
+                       if (target_type == TypeManager.float_type)
+                               return new FloatConstant ((float) Value, Location);
+                       if (target_type == TypeManager.double_type)
+                               return new DoubleConstant ((double) Value, Location);
+                       if (target_type == TypeManager.decimal_type)
+                               return new DecimalConstant ((decimal) Value, Location);
+
+                       return null;
                }
+
        }
+
+       public class SByteConstant : Constant {
+               public readonly sbyte Value;
+
+               public SByteConstant (sbyte v, Location loc):
+                       base (loc)
+               {
+                       type = TypeManager.sbyte_type;
+                       eclass = ExprClass.Value;
+                       Value = v;
+               }
+
+               public override void Emit (EmitContext ec)
+               {
+                       IntLiteral.EmitInt (ec.ig, Value);
+               }
+
+               public override string AsString ()
+               {
+                       return Value.ToString ();
+               }
+
+               public override object GetValue ()
+               {
+                       return Value;
+               }
+
+               public override DoubleConstant ConvertToDouble ()
+               {
+                       return new DoubleConstant (Value, loc);
+               }
+
+               public override FloatConstant ConvertToFloat ()
+               {
+                       return new FloatConstant (Value, loc);
+               }
+
+               public override ULongConstant ConvertToULong ()
+               {
+                       if (Value >= 0)
+                               return new ULongConstant ((ulong) Value, loc);
+                       
+                       return null;
+               }
+
+               public override LongConstant ConvertToLong ()
+               {
+                       return new LongConstant (Value, loc);
+               }
+
+               public override UIntConstant ConvertToUInt ()
+               {
+                       return null;
+               }
+
+               public override IntConstant ConvertToInt ()
+               {
+                       return new IntConstant (Value, loc);
+               }
+
+               public override Constant Increment ()
+               {
+                   return new SByteConstant (checked((sbyte)(Value + 1)), loc);
+               }
+
+               public override bool IsDefaultValue {
+                       get {
+                               return Value == 0;
+                       }
+               }
+
+               public override bool IsNegative {
+                       get {
+                               return Value < 0;
+                       }
+               }
+               
+               public override bool IsZeroInteger {
+                       get { return Value == 0; }
+               }
+
+               public override Constant Reduce (EmitContext ec, Type target_type)
+               {
+                       if (target_type == TypeManager.byte_type) {
+                               CheckUnsigned (ec, Value, target_type);
+                               return new ByteConstant ((byte) Value, Location);
+                       }
+                       if (target_type == TypeManager.short_type)
+                               return new ShortConstant ((short) Value, Location);
+                       if (target_type == TypeManager.ushort_type) {
+                               CheckUnsigned (ec, Value, target_type);
+                               return new UShortConstant ((ushort) Value, Location);
+                       } if (target_type == TypeManager.int32_type)
+                                 return new IntConstant ((int) Value, Location);
+                       if (target_type == TypeManager.uint32_type) {
+                               CheckUnsigned (ec, Value, target_type);
+                               return new UIntConstant ((uint) Value, Location);
+                       } if (target_type == TypeManager.int64_type)
+                                 return new LongConstant ((long) Value, Location);
+                       if (target_type == TypeManager.uint64_type) {
+                               CheckUnsigned (ec, Value, target_type);
+                               return new ULongConstant ((ulong) Value, Location);
+                       }
+                       if (target_type == TypeManager.float_type)
+                               return new FloatConstant ((float) Value, Location);
+                       if (target_type == TypeManager.double_type)
+                               return new DoubleConstant ((double) Value, Location);
+                       if (target_type == TypeManager.char_type) {
+                               CheckUnsigned (ec, Value, target_type);
+                               return new CharConstant ((char) Value, Location);
+                       }
+                       if (target_type == TypeManager.decimal_type)
+                               return new DecimalConstant ((decimal) Value, Location);
+
+                       return null;
+               }
+
+       }
+
+       public class ShortConstant : Constant {
+               public readonly short Value;
+
+               public ShortConstant (short v, Location loc):
+                       base (loc)
+               {
+                       type = TypeManager.short_type;
+                       eclass = ExprClass.Value;
+                       Value = v;
+               }
+
+               public override void Emit (EmitContext ec)
+               {
+                       IntLiteral.EmitInt (ec.ig, Value);
+               }
+
+               public override string AsString ()
+               {
+                       return Value.ToString ();
+               }
+
+               public override object GetValue ()
+               {
+                       return Value;
+               }
+
+               public override DoubleConstant ConvertToDouble ()
+               {
+                       return new DoubleConstant (Value, loc);
+               }
+
+               public override FloatConstant ConvertToFloat ()
+               {
+                       return new FloatConstant (Value, loc);
+               }
+
+               public override ULongConstant ConvertToULong ()
+               {
+                       return null;
+               }
+
+               public override LongConstant ConvertToLong ()
+               {
+                       return new LongConstant (Value, loc);
+               }
+
+               public override UIntConstant ConvertToUInt ()
+               {
+                       return null;
+               }
+
+               public override IntConstant ConvertToInt ()
+               {
+                       return new IntConstant (Value, loc);
+               }
+
+               public override Constant Increment ()
+               {
+                       return new ShortConstant (checked((short)(Value + 1)), loc);
+               }
+
+               public override bool IsDefaultValue {
+                       get {
+                               return Value == 0;
+                       }
+               }
+               
+               public override bool IsZeroInteger {
+                       get { return Value == 0; }
+               }
+
+               public override bool IsNegative {
+                       get {
+                               return Value < 0;
+                       }
+               }
+
+               public override Constant Reduce (EmitContext ec, Type target_type)
+               {
+                       if (target_type == TypeManager.byte_type) {
+                               CheckRange (ec, Value, target_type, Byte.MinValue, Byte.MaxValue);
+                               return new ByteConstant ((byte) Value, Location);
+                       }
+                       if (target_type == TypeManager.sbyte_type) {
+                               CheckRange (ec, Value, target_type, SByte.MinValue, SByte.MaxValue);
+                               return new SByteConstant ((sbyte) Value, Location);
+                       }
+                       if (target_type == TypeManager.ushort_type) {
+                               CheckUnsigned (ec, Value, target_type);
+                               return new UShortConstant ((ushort) Value, Location);
+                       }
+                       if (target_type == TypeManager.int32_type)
+                               return new IntConstant ((int) Value, Location);
+                       if (target_type == TypeManager.uint32_type) {
+                               CheckUnsigned (ec, Value, target_type);
+                               return new UIntConstant ((uint) Value, Location);
+                       }
+                       if (target_type == TypeManager.int64_type)
+                               return new LongConstant ((long) Value, Location);
+                       if (target_type == TypeManager.uint64_type) {
+                               CheckUnsigned (ec, Value, target_type);
+                               return new ULongConstant ((ulong) Value, Location);
+                       }
+                       if (target_type == TypeManager.float_type)
+                               return new FloatConstant ((float) Value, Location);
+                       if (target_type == TypeManager.double_type)
+                               return new DoubleConstant ((double) Value, Location);
+                       if (target_type == TypeManager.char_type) {
+                               CheckRange (ec, Value, target_type, Char.MinValue, Char.MaxValue);
+                               return new CharConstant ((char) Value, Location);
+                       }
+                       if (target_type == TypeManager.decimal_type)
+                               return new DecimalConstant ((decimal) Value, Location);
+
+                       return null;
+               }
+
+       }
+
+       public class UShortConstant : Constant {
+               public readonly ushort Value;
+
+               public UShortConstant (ushort v, Location loc):
+                       base (loc)
+               {
+                       type = TypeManager.ushort_type;
+                       eclass = ExprClass.Value;
+                       Value = v;
+               }
+
+               public override void Emit (EmitContext ec)
+               {
+                       IntLiteral.EmitInt (ec.ig, Value);
+               }
+
+               public override string AsString ()
+               {
+                       return Value.ToString ();
+               }
+
+               public override object GetValue ()
+               {
+                       return Value;
+               }
+
+               public override DoubleConstant ConvertToDouble ()
+               {
+                       return new DoubleConstant (Value, loc);
+               }
+
+               public override FloatConstant ConvertToFloat ()
+               {
+                       return new FloatConstant (Value, loc);
+               }
+
+               public override ULongConstant ConvertToULong ()
+               {
+                       return new ULongConstant (Value, loc);
+               }
+
+               public override LongConstant ConvertToLong ()
+               {
+                       return new LongConstant (Value, loc);
+               }
+
+               public override UIntConstant ConvertToUInt ()
+               {
+                       return new UIntConstant (Value, loc);
+               }
+
+               public override IntConstant ConvertToInt ()
+               {
+                       return new IntConstant (Value, loc);
+               }
+       
+               public override Constant Increment ()
+               {
+                       return new UShortConstant (checked((ushort)(Value + 1)), loc);
+               }
+
+               public override bool IsDefaultValue {
+                       get {
+                               return Value == 0;
+                       }
+               }
+
+               public override bool IsNegative {
+                       get {
+                               return false;
+                       }
+               }
+       
+               public override bool IsZeroInteger {
+                       get { return Value == 0; }
+               }
+
+               public override Constant Reduce (EmitContext ec, Type target_type)
+               {
+                       if (target_type == TypeManager.byte_type) {
+                               CheckRange (ec, Value, target_type, Byte.MinValue, Byte.MaxValue);
+                               return new ByteConstant ((byte) Value, Location);
+                       }
+                       if (target_type == TypeManager.sbyte_type) {
+                               CheckRange (ec, Value, target_type, SByte.MinValue, SByte.MaxValue);
+                               return new SByteConstant ((sbyte) Value, Location);
+                       }
+                       if (target_type == TypeManager.short_type) {
+                               CheckRange (ec, Value, target_type, Int16.MinValue, Int16.MaxValue);
+                               return new ShortConstant ((short) Value, Location);
+                       }
+                       if (target_type == TypeManager.int32_type)
+                               return new IntConstant ((int) Value, Location);
+                       if (target_type == TypeManager.uint32_type)
+                               return new UIntConstant ((uint) Value, Location);
+                       if (target_type == TypeManager.int64_type)
+                               return new LongConstant ((long) Value, Location);
+                       if (target_type == TypeManager.uint64_type)
+                               return new ULongConstant ((ulong) Value, Location);
+                       if (target_type == TypeManager.float_type)
+                               return new FloatConstant ((float) Value, Location);
+                       if (target_type == TypeManager.double_type)
+                               return new DoubleConstant ((double) Value, Location);
+                       if (target_type == TypeManager.char_type) {
+                               CheckRange (ec, Value, target_type, Char.MinValue, Char.MaxValue);
+                               return new CharConstant ((char) Value, Location);
+                       }
+                       if (target_type == TypeManager.decimal_type)
+                               return new DecimalConstant ((decimal) Value, Location);
+
+                       return null;
+               }
+       }
+
+       public class IntConstant : Constant {
+               public readonly int Value;
+
+               public IntConstant (int v, Location loc):
+                       base (loc)
+               {
+                       type = TypeManager.int32_type;
+                       eclass = ExprClass.Value;
+                       Value = v;
+               }
+
+               static public void EmitInt (ILGenerator ig, int i)
+               {
+                       switch (i){
+                       case -1:
+                               ig.Emit (OpCodes.Ldc_I4_M1);
+                               break;
+                               
+                       case 0:
+                               ig.Emit (OpCodes.Ldc_I4_0);
+                               break;
+                               
+                       case 1:
+                               ig.Emit (OpCodes.Ldc_I4_1);
+                               break;
+                               
+                       case 2:
+                               ig.Emit (OpCodes.Ldc_I4_2);
+                               break;
+                               
+                       case 3:
+                               ig.Emit (OpCodes.Ldc_I4_3);
+                               break;
+                               
+                       case 4:
+                               ig.Emit (OpCodes.Ldc_I4_4);
+                               break;
+                               
+                       case 5:
+                               ig.Emit (OpCodes.Ldc_I4_5);
+                               break;
+                               
+                       case 6:
+                               ig.Emit (OpCodes.Ldc_I4_6);
+                               break;
+                               
+                       case 7:
+                               ig.Emit (OpCodes.Ldc_I4_7);
+                               break;
+                               
+                       case 8:
+                               ig.Emit (OpCodes.Ldc_I4_8);
+                               break;
+
+                       default:
+                               if (i >= -128 && i <= 127){
+                                       ig.Emit (OpCodes.Ldc_I4_S, (sbyte) i);
+                               } else
+                                       ig.Emit (OpCodes.Ldc_I4, i);
+                               break;
+                       }
+               }
+
+               public override void Emit (EmitContext ec)
+               {
+                       EmitInt (ec.ig, Value);
+               }
+
+               public override string AsString ()
+               {
+                       return Value.ToString ();
+               }
+
+               public override object GetValue ()
+               {
+                       return Value;
+               }
+
+               public override DecimalConstant ConvertToDecimal()
+               {
+                       return new DecimalConstant (Value, loc);
+               }
+
+               public override DoubleConstant ConvertToDouble ()
+               {
+                       return new DoubleConstant (Value, loc);
+               }
+
+               public override FloatConstant ConvertToFloat ()
+               {
+                       return new FloatConstant (Value, loc);
+               }
+
+               public override ULongConstant ConvertToULong ()
+               {
+                       if (Value < 0)
+                               return null;
+
+                       return new ULongConstant ((ulong) Value, loc);
+               }
+
+               public override LongConstant ConvertToLong ()
+               {
+                       return new LongConstant (Value, loc);
+               }
+
+               public override UIntConstant ConvertToUInt ()
+               {
+                       if (Value < 0)
+                               return null;
+
+                       return new UIntConstant ((uint) Value, loc);
+               }
+
+               public override IntConstant ConvertToInt ()
+               {
+                       return this;
+               }
+
+               public override Constant Increment ()
+               {
+                       return new IntConstant (checked(Value + 1), loc);
+               }
+
+               public override bool IsDefaultValue {
+                       get {
+                               return Value == 0;
+                       }
+               }
+               
+               public override bool IsNegative {
+                       get {
+                               return Value < 0;
+                       }
+               }
+
+               public override bool IsZeroInteger {
+                       get { return Value == 0; }
+               }
+
+               public override Constant Reduce (EmitContext ec, Type target_type)
+               {
+                       if (target_type == TypeManager.byte_type) {
+                               CheckRange (ec, Value, target_type, Byte.MinValue, Byte.MaxValue);
+                               return new ByteConstant ((byte) Value, Location);
+                       }
+                       if (target_type == TypeManager.sbyte_type) {
+                               CheckRange (ec, Value, target_type, SByte.MinValue, SByte.MaxValue);
+                               return new SByteConstant ((sbyte) Value, Location);
+                       }
+                       if (target_type == TypeManager.short_type) {
+                               CheckRange (ec, Value, target_type, Int16.MinValue, Int16.MaxValue);
+                               return new ShortConstant ((short) Value, Location);
+                       }
+                       if (target_type == TypeManager.ushort_type) {
+                               CheckRange (ec, Value, target_type, UInt16.MinValue, UInt16.MaxValue);
+                               return new UShortConstant ((ushort) Value, Location);
+                       }
+                       if (target_type == TypeManager.uint32_type) {
+                               CheckRange (ec, Value, target_type, Int32.MinValue, Int32.MaxValue);
+                               return new UIntConstant ((uint) Value, Location);
+                       }
+                       if (target_type == TypeManager.int64_type)
+                               return new LongConstant ((long) Value, Location);
+                       if (target_type == TypeManager.uint64_type) {
+                               CheckUnsigned (ec, Value, target_type);
+                               return new ULongConstant ((ulong) Value, Location);
+                       }
+                       if (target_type == TypeManager.float_type)
+                               return new FloatConstant ((float) Value, Location);
+                       if (target_type == TypeManager.double_type)
+                               return new DoubleConstant ((double) Value, Location);
+                       if (target_type == TypeManager.char_type) {
+                               CheckRange (ec, Value, target_type, Char.MinValue, Char.MaxValue);
+                               return new CharConstant ((char) Value, Location);
+                       }
+                       if (target_type == TypeManager.decimal_type)
+                               return new DecimalConstant ((decimal) Value, Location);
+
+                       return null;
+               }
+       }
+
+       public class UIntConstant : Constant {
+               public readonly uint Value;
+
+               public UIntConstant (uint v, Location loc):
+                       base (loc)
+               {
+                       type = TypeManager.uint32_type;
+                       eclass = ExprClass.Value;
+                       Value = v;
+               }
+
+               public override void Emit (EmitContext ec)
+               {
+                       IntLiteral.EmitInt (ec.ig, unchecked ((int) Value));
+               }
+
+               public override string AsString ()
+               {
+                       return Value.ToString ();
+               }
+
+               public override object GetValue ()
+               {
+                       return Value;
+               }
+
+               public override DoubleConstant ConvertToDouble ()
+               {
+                       return new DoubleConstant (Value, loc);
+               }
+
+               public override FloatConstant ConvertToFloat ()
+               {
+                       return new FloatConstant (Value, loc);
+               }
+
+               public override ULongConstant ConvertToULong ()
+               {
+                       return new ULongConstant (Value, loc);
+               }
+
+               public override LongConstant ConvertToLong ()
+               {
+                       return new LongConstant (Value, loc);
+               }
+
+               public override UIntConstant ConvertToUInt ()
+               {
+                       return this;
+               }
+
+               public override IntConstant ConvertToInt ()
+               {
+                       return null;
+               }
+       
+               public override Constant Increment ()
+               {
+                       return new UIntConstant (checked(Value + 1), loc);
+               }
+       
+               public override bool IsDefaultValue {
+                       get {
+                               return Value == 0;
+                       }
+               }
+
+               public override bool IsNegative {
+                       get {
+                               return false;
+                       }
+               }
+
+               public override bool IsZeroInteger {
+                       get { return Value == 0; }
+               }
+
+               public override Constant Reduce (EmitContext ec, Type target_type)
+               {
+                       if (target_type == TypeManager.byte_type) {
+                               CheckRange (ec, Value, target_type, Char.MinValue, Char.MaxValue);
+                               return new ByteConstant ((byte) Value, Location);
+                       }
+                       if (target_type == TypeManager.sbyte_type) {
+                               CheckRange (ec, Value, target_type, SByte.MinValue, SByte.MaxValue);
+                               return new SByteConstant ((sbyte) Value, Location);
+                       }
+                       if (target_type == TypeManager.short_type) {
+                               CheckRange (ec, Value, target_type, Int16.MinValue, Int16.MaxValue);
+                               return new ShortConstant ((short) Value, Location);
+                       }
+                       if (target_type == TypeManager.ushort_type) {
+                               CheckRange (ec, Value, target_type, UInt16.MinValue, UInt16.MaxValue);
+                               return new UShortConstant ((ushort) Value, Location);
+                       }
+                       if (target_type == TypeManager.int32_type) {
+                               CheckRange (ec, Value, target_type, Int32.MinValue, Int32.MaxValue);
+                               return new IntConstant ((int) Value, Location);
+                       }
+                       if (target_type == TypeManager.int64_type)
+                               return new LongConstant ((long) Value, Location);
+                       if (target_type == TypeManager.uint64_type)
+                               return new ULongConstant ((ulong) Value, Location);
+                       if (target_type == TypeManager.float_type)
+                               return new FloatConstant ((float) Value, Location);
+                       if (target_type == TypeManager.double_type)
+                               return new DoubleConstant ((double) Value, Location);
+                       if (target_type == TypeManager.char_type) {
+                               CheckRange (ec, Value, target_type, Char.MinValue, Char.MaxValue);
+                               return new CharConstant ((char) Value, Location);
+                       }
+                       if (target_type == TypeManager.decimal_type)
+                               return new DecimalConstant ((decimal) Value, Location);
+
+                       return null;
+               }
+
+       }
+
+       public class LongConstant : Constant {
+               public readonly long Value;
+
+               public LongConstant (long v, Location loc):
+                       base (loc)
+               {
+                       type = TypeManager.int64_type;
+                       eclass = ExprClass.Value;
+                       Value = v;
+               }
+
+               public override void Emit (EmitContext ec)
+               {
+                       ILGenerator ig = ec.ig;
+
+                       EmitLong (ig, Value);
+               }
+
+               static public void EmitLong (ILGenerator ig, long l)
+               {
+                       if ((l >> 32) == 0){
+                               IntLiteral.EmitInt (ig, unchecked ((int) l));
+                               ig.Emit (OpCodes.Conv_U8);
+                       } else {
+                               ig.Emit (OpCodes.Ldc_I8, l);
+                       }
+               }
+
+               public override string AsString ()
+               {
+                       return Value.ToString ();
+               }
+
+               public override object GetValue ()
+               {
+                       return Value;
+               }
+
+               public override DoubleConstant ConvertToDouble ()
+               {
+                       return new DoubleConstant (Value, loc);
+               }
+
+               public override FloatConstant ConvertToFloat ()
+               {
+                       return new FloatConstant (Value, loc);
+               }
+
+               public override ULongConstant ConvertToULong ()
+               {
+                       if (Value < 0)
+                               return null;
+                       
+                       return new ULongConstant ((ulong) Value, loc);
+               }
+
+               public override LongConstant ConvertToLong ()
+               {
+                       return this;
+               }
+
+               public override UIntConstant ConvertToUInt ()
+               {
+                       return null;
+               }
+
+               public override IntConstant ConvertToInt ()
+               {
+                       return null;
+               }
+
+               public override Constant Increment ()
+               {
+                       return new LongConstant (checked(Value + 1), loc);
+               }
+               
+               public override bool IsDefaultValue {
+                       get {
+                               return Value == 0;
+                       }
+               }
+
+               public override bool IsNegative {
+                       get {
+                               return Value < 0;
+                       }
+               }
+
+               public override bool IsZeroInteger {
+                       get { return Value == 0; }
+               }
+
+               public override Constant Reduce (EmitContext ec, Type target_type)
+               {
+                       if (target_type == TypeManager.byte_type) {
+                               CheckRange (ec, Value, target_type, Byte.MinValue, Byte.MaxValue);
+                               return new ByteConstant ((byte) Value, Location);
+                       }
+                       if (target_type == TypeManager.sbyte_type) {
+                               CheckRange (ec, Value, target_type, SByte.MinValue, SByte.MaxValue);
+                               return new SByteConstant ((sbyte) Value, Location);
+                       }
+                       if (target_type == TypeManager.short_type) {
+                               CheckRange (ec, Value, target_type, Int16.MinValue, Int16.MaxValue);
+                               return new ShortConstant ((short) Value, Location);
+                       }
+                       if (target_type == TypeManager.ushort_type) {
+                               CheckRange (ec, Value, target_type, UInt16.MinValue, UInt16.MaxValue);
+                               return new UShortConstant ((ushort) Value, Location);
+                       }
+                       if (target_type == TypeManager.int32_type) {
+                               CheckRange (ec, Value, target_type, Int32.MinValue, Int32.MaxValue);
+                               return new IntConstant ((int) Value, Location);
+                       }
+                       if (target_type == TypeManager.uint32_type) {
+                               CheckRange (ec, Value, target_type, UInt32.MinValue, UInt32.MaxValue);
+                               return new UIntConstant ((uint) Value, Location);
+                       }
+                       if (target_type == TypeManager.uint64_type) {
+                               CheckUnsigned (ec, Value, target_type);
+                               return new ULongConstant ((ulong) Value, Location);
+                       }
+                       if (target_type == TypeManager.float_type)
+                               return new FloatConstant ((float) Value, Location);
+                       if (target_type == TypeManager.double_type)
+                               return new DoubleConstant ((double) Value, Location);
+                       if (target_type == TypeManager.char_type) {
+                               CheckRange (ec, Value, target_type, Char.MinValue, Char.MaxValue);
+                               return new CharConstant ((char) Value, Location);
+                       }
+                       if (target_type == TypeManager.decimal_type)
+                               return new DecimalConstant ((decimal) Value, Location);
+
+                       return null;
+               }
+
+       }
+
+       public class ULongConstant : Constant {
+               public readonly ulong Value;
+
+               public ULongConstant (ulong v, Location loc):
+                       base (loc)
+               {
+                       type = TypeManager.uint64_type;
+                       eclass = ExprClass.Value;
+                       Value = v;
+               }
+
+               public override void Emit (EmitContext ec)
+               {
+                       ILGenerator ig = ec.ig;
+
+                       LongLiteral.EmitLong (ig, unchecked ((long) Value));
+               }
+
+               public override string AsString ()
+               {
+                       return Value.ToString ();
+               }
+
+               public override object GetValue ()
+               {
+                       return Value;
+               }
+
+               public override DoubleConstant ConvertToDouble ()
+               {
+                       return new DoubleConstant (Value, loc);
+               }
+
+               public override FloatConstant ConvertToFloat ()
+               {
+                       return new FloatConstant (Value, loc);
+               }
+
+               public override ULongConstant ConvertToULong ()
+               {
+                       return this;
+               }
+
+               public override LongConstant ConvertToLong ()
+               {
+                       return null;
+               }
+
+               public override UIntConstant ConvertToUInt ()
+               {
+                       return null;
+               }
+
+               public override IntConstant ConvertToInt ()
+               {
+                       return null;
+               }
+
+               public override Constant Increment ()
+               {
+                       return new ULongConstant (checked(Value + 1), loc);
+               }
+
+               public override bool IsDefaultValue {
+                       get {
+                               return Value == 0;
+                       }
+               }
+
+               public override bool IsNegative {
+                       get {
+                               return false;
+                       }
+               }
+
+               public override bool IsZeroInteger {
+                       get { return Value == 0; }
+               }
+
+               public override Constant Reduce (EmitContext ec, Type target_type)
+               {
+                       if (target_type == TypeManager.byte_type) {
+                               CheckRange (ec, Value, target_type, Byte.MaxValue);
+                               return new ByteConstant ((byte) Value, Location);
+                       }
+                       if (target_type == TypeManager.sbyte_type) {
+                               CheckRange (ec, Value, target_type, (ulong) SByte.MaxValue);
+                               return new SByteConstant ((sbyte) Value, Location);
+                       }
+                       if (target_type == TypeManager.short_type) {
+                               CheckRange (ec, Value, target_type, (ulong) Int16.MaxValue);
+                               return new ShortConstant ((short) Value, Location);
+                       }
+                       if (target_type == TypeManager.ushort_type) {
+                               CheckRange (ec, Value, target_type, UInt16.MaxValue);
+                               return new UShortConstant ((ushort) Value, Location);
+                       }
+                       if (target_type == TypeManager.int32_type) {
+                               CheckRange (ec, Value, target_type, Int32.MaxValue);
+                               return new IntConstant ((int) Value, Location);
+                       }
+                       if (target_type == TypeManager.uint32_type) {
+                               CheckRange (ec, Value, target_type, UInt32.MaxValue);
+                               return new UIntConstant ((uint) Value, Location);
+                       }
+                       if (target_type == TypeManager.int64_type) {
+                               CheckRange (ec, Value, target_type, (ulong) Int64.MaxValue);
+                               return new LongConstant ((long) Value, Location);
+                       }
+                       if (target_type == TypeManager.float_type)
+                               return new FloatConstant ((float) Value, Location);
+                       if (target_type == TypeManager.double_type)
+                               return new DoubleConstant ((double) Value, Location);
+                       if (target_type == TypeManager.char_type) {
+                               CheckRange (ec, Value, target_type, Char.MaxValue);
+                               return new CharConstant ((char) Value, Location);
+                       }
+                       if (target_type == TypeManager.decimal_type)
+                               return new DecimalConstant ((decimal) Value, Location);
+
+                       return null;
+               }
+
+       }
+
+       public class FloatConstant : Constant {
+               public readonly float Value;
+
+               public FloatConstant (float v, Location loc):
+                       base (loc)
+               {
+                       type = TypeManager.float_type;
+                       eclass = ExprClass.Value;
+                       Value = v;
+               }
+
+               public override void Emit (EmitContext ec)
+               {
+                       ec.ig.Emit (OpCodes.Ldc_R4, Value);
+               }
+
+               public override string AsString ()
+               {
+                       return Value.ToString ();
+               }
+
+               public override object GetValue ()
+               {
+                       return Value;
+               }
+
+               public override DoubleConstant ConvertToDouble ()
+               {
+                       return new DoubleConstant (Value, loc);
+               }
+
+               public override FloatConstant ConvertToFloat ()
+               {
+                       return this;
+               }
+
+               public override LongConstant ConvertToLong ()
+               {
+                       return null;
+               }
+
+               public override UIntConstant ConvertToUInt ()
+               {
+                       return null;
+               }
+
+               public override IntConstant ConvertToInt ()
+               {
+                       return null;
+               }
+
+               public override Constant Increment ()
+               {
+                       return new FloatConstant (checked(Value + 1), loc);
+               }
+
+               public override bool IsDefaultValue {
+                       get {
+                               return Value == 0;
+                       }
+               }
+
+               public override bool IsNegative {
+                       get {
+                               return Value < 0;
+                       }
+               }
+
+               public override Constant Reduce (EmitContext ec, Type target_type)
+               {
+                       if (target_type == TypeManager.byte_type)
+                               return new ByteConstant ((byte) Value, Location);
+                       if (target_type == TypeManager.sbyte_type)
+                               return new SByteConstant ((sbyte) Value, Location);
+                       if (target_type == TypeManager.short_type)
+                               return new ShortConstant ((short) Value, Location);
+                       if (target_type == TypeManager.ushort_type)
+                               return new UShortConstant ((ushort) Value, Location);
+                       if (target_type == TypeManager.int32_type)
+                               return new IntConstant ((int) Value, Location);
+                       if (target_type == TypeManager.uint32_type)
+                               return new UIntConstant ((uint) Value, Location);
+                       if (target_type == TypeManager.int64_type)
+                               return new LongConstant ((long) Value, Location);
+                       if (target_type == TypeManager.uint64_type)
+                               return new ULongConstant ((ulong) Value, Location);
+                       if (target_type == TypeManager.double_type)
+                               return new DoubleConstant ((double) Value, Location);
+                       if (target_type == TypeManager.char_type)
+                               return new CharConstant ((char) Value, Location);
+                       if (target_type == TypeManager.decimal_type)
+                               return new DecimalConstant ((decimal) Value, Location);
+
+                       return null;
+               }
+
+       }
+
+       public class DoubleConstant : Constant {
+               public readonly double Value;
+
+               public DoubleConstant (double v, Location loc):
+                       base (loc)
+               {
+                       type = TypeManager.double_type;
+                       eclass = ExprClass.Value;
+                       Value = v;
+               }
+
+               public override void Emit (EmitContext ec)
+               {
+                       ec.ig.Emit (OpCodes.Ldc_R8, Value);
+               }
+
+               public override string AsString ()
+               {
+                       return Value.ToString ();
+               }
+
+               public override object GetValue ()
+               {
+                       return Value;
+               }
+
+               public override DoubleConstant ConvertToDouble ()
+               {
+                       return this;
+               }
+
+               public override FloatConstant ConvertToFloat ()
+               {
+                       return null;
+               }
+
+               public override ULongConstant ConvertToULong ()
+               {
+                       return null;
+               }
+
+               public override LongConstant ConvertToLong ()
+               {
+                       return null;
+               }
+
+               public override UIntConstant ConvertToUInt ()
+               {
+                       return null;
+               }
+
+               public override IntConstant ConvertToInt ()
+               {
+                       return null;
+               }
+
+               public override Constant Increment ()
+               {
+                       return new DoubleConstant (checked(Value + 1), loc);
+               }
+
+               public override bool IsDefaultValue {
+                       get {
+                               return Value == 0;
+                       }
+               }
+
+               public override bool IsNegative {
+                       get {
+                               return Value < 0;
+                       }
+               }
+
+               public override Constant Reduce (EmitContext ec, Type target_type)
+               {
+                       if (target_type == TypeManager.byte_type) {
+                               CheckRange (ec, Value, target_type, Byte.MinValue, Byte.MaxValue);
+                               return new ByteConstant ((byte) Value, Location);
+                       }
+                       if (target_type == TypeManager.sbyte_type) {
+                               CheckRange (ec, Value, target_type, SByte.MinValue, SByte.MaxValue);
+                               return new SByteConstant ((sbyte) Value, Location);
+                       }
+                       if (target_type == TypeManager.short_type)
+                               return new ShortConstant ((short) Value, Location);
+                       if (target_type == TypeManager.ushort_type)
+                               return new UShortConstant ((ushort) Value, Location);
+                       if (target_type == TypeManager.int32_type)
+                               return new IntConstant ((int) Value, Location);
+                       if (target_type == TypeManager.uint32_type)
+                               return new UIntConstant ((uint) Value, Location);
+                       if (target_type == TypeManager.int64_type)
+                               return new LongConstant ((long) Value, Location);
+                       if (target_type == TypeManager.uint64_type)
+                               return new ULongConstant ((ulong) Value, Location);
+                       if (target_type == TypeManager.float_type)
+                               return new FloatConstant ((float) Value, Location);
+                       if (target_type == TypeManager.char_type) {
+                               CheckRange (ec, Value, target_type, char.MinValue, char.MaxValue);
+                               return new CharConstant ((char) Value, Location);
+                       }
+                       if (target_type == TypeManager.decimal_type)
+                               return new DecimalConstant ((decimal) Value, Location);
+
+                       return null;
+               }
+
+       }
+
+       public class DecimalConstant : Constant {
+               public readonly decimal Value;
+
+               public DecimalConstant (decimal d, Location loc):
+                       base (loc)
+               {
+                       type = TypeManager.decimal_type;
+                       eclass = ExprClass.Value;
+                       Value = d;
+               }
+
+               override public string AsString ()
+               {
+                       return Value.ToString ();
+               }
+
+               public override object GetValue ()
+               {
+                       return (object) Value;
+               }
+
+               public override void Emit (EmitContext ec)
+               {
+                       ILGenerator ig = ec.ig;
+
+                       int [] words = Decimal.GetBits (Value);
+                       int power = (words [3] >> 16) & 0xff;
+
+                       if (power == 0 && Value <= int.MaxValue && Value >= int.MinValue)
+                       {
+                               IntConstant.EmitInt (ig, (int)Value);
+                               ig.Emit (OpCodes.Newobj, TypeManager.void_decimal_ctor_int_arg);
+                               return;
+                       }
+
+                       
+                       //
+                       // FIXME: we could optimize this, and call a better 
+                       // constructor
+                       //
+
+                       IntConstant.EmitInt (ig, words [0]);
+                       IntConstant.EmitInt (ig, words [1]);
+                       IntConstant.EmitInt (ig, words [2]);
+
+                       // sign
+                       IntConstant.EmitInt (ig, words [3] >> 31);
+
+                       // power
+                       IntConstant.EmitInt (ig, power);
+
+                       ig.Emit (OpCodes.Newobj, TypeManager.void_decimal_ctor_five_args);
+               }
+
+               public override Constant Increment ()
+               {
+                       return new DecimalConstant (checked (Value + 1), loc);
+               }
+
+               public override bool IsDefaultValue {
+                       get {
+                               return Value == 0;
+                       }
+               }
+
+               public override bool IsNegative {
+                       get {
+                               return Value < 0;
+                       }
+               }
+
+               public override Constant Reduce (EmitContext ec, Type target_type)
+               {
+                       if (target_type == TypeManager.sbyte_type)
+                               return new SByteConstant ((sbyte)Value, loc);
+                       if (target_type == TypeManager.byte_type)
+                               return new ByteConstant ((byte)Value, loc);
+                       if (target_type == TypeManager.short_type)
+                               return new ShortConstant ((short)Value, loc);
+                       if (target_type == TypeManager.ushort_type)
+                               return new UShortConstant ((ushort)Value, loc);
+                       if (target_type == TypeManager.int32_type)
+                               return new IntConstant ((int)Value, loc);
+                       if (target_type == TypeManager.uint32_type)
+                               return new UIntConstant ((uint)Value, loc);
+                       if (target_type == TypeManager.int64_type)
+                               return new LongConstant ((long)Value, loc);
+                       if (target_type == TypeManager.uint64_type)
+                               return new ULongConstant ((ulong)Value, loc);
+                       if (target_type == TypeManager.char_type)
+                               return new CharConstant ((char)Value, loc);
+                       if (target_type == TypeManager.float_type)
+                               return new FloatConstant ((float)Value, loc);
+                       if (target_type == TypeManager.double_type)
+                               return new DoubleConstant ((double)Value, loc);
+
+                       return null;
+               }
+
+       }
+
+       public class StringConstant : Constant {
+               public readonly string Value;
+
+               public StringConstant (string s, Location loc):
+                       base (loc)
+               {
+                       type = TypeManager.string_type;
+                       eclass = ExprClass.Value;
+                       Value = s;
+               }
+
+               // FIXME: Escape the string.
+               override public string AsString ()
+               {
+                       return "\"" + Value + "\"";
+               }
+
+               public override object GetValue ()
+               {
+                       return Value;
+               }
+               
+               public override void Emit (EmitContext ec)
+               {
+                       if (Value == null)
+                               ec.ig.Emit (OpCodes.Ldnull);
+                       else
+                               ec.ig.Emit (OpCodes.Ldstr, Value);
+               }
+
+               public override Constant Increment ()
+               {
+                       throw new NotSupportedException ();
+               }
+
+               public override bool IsDefaultValue {
+                       get {
+                               return Value == null;
+                       }
+               }
+
+               public override bool IsNegative {
+                       get {
+                               return false;
+                       }
+               }
+
+               public override Constant Reduce (EmitContext ec, Type target_type)
+               {
+                       return null;
+               }
+       }
+
 }