X-Git-Url: http://wien.tomnetworks.com/gitweb/?a=blobdiff_plain;f=mcs%2Fmcs%2Fconstant.cs;h=18ca2dd7bdd3d8f57defbfb04817b737b351abec;hb=a4c049eb2217fb63d763181b7a1280b2190ebe31;hp=b97972b79778cbe645fb6a4cbe0ceda4d3d7dabc;hpb=2ca4ca638d4805527be8e12dd7ddacaf12a70ea4;p=mono.git

diff --git a/mcs/mcs/constant.cs b/mcs/mcs/constant.cs
old mode 100755
new mode 100644
index b97972b7977..18ca2dd7bdd
--- a/mcs/mcs/constant.cs
+++ b/mcs/mcs/constant.cs
@@ -1,100 +1,1913 @@
-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;
+		}
+	}
+
 }