// lambda.cs: support for lambda expressions
//
// Authors: Miguel de Icaza (miguel@gnu.org)
+// Marek Safar (marek.safar@gmail.com)
//
-// Licensed under the terms of the GNU GPL
+// Dual licensed under the terms of the MIT X11 or GNU GPL
//
-// (C) 2007 Novell, Inc
+// Copyright 2007-2008 Novell, Inc
//
using System;
using System.Collections;
+using System.Reflection;
+using System.Reflection.Emit;
namespace Mono.CSharp {
- public class LambdaExpression : Expression {
- public LambdaExpression (ArrayList parameters, object body, Location loc)
+ public class LambdaExpression : AnonymousMethodExpression
+ {
+ readonly bool explicit_parameters;
+
+ //
+ // The parameters can either be:
+ // A list of Parameters (explicitly typed parameters)
+ // An ImplicitLambdaParameter
+ //
+ public LambdaExpression (Parameters parameters, Location loc)
+ : base (parameters, loc)
+ {
+ if (parameters.Count > 0)
+ explicit_parameters = !(parameters.FixedParameters [0] is ImplicitLambdaParameter);
+ }
+
+ protected override Expression CreateExpressionTree (EmitContext ec, Type delegate_type)
+ {
+ if (ec.IsInProbingMode)
+ return this;
+
+ Expression args = Parameters.CreateExpressionTree (ec, loc);
+ Expression expr = Block.CreateExpressionTree (ec);
+ if (expr == null)
+ return null;
+
+ ArrayList arguments = new ArrayList (2);
+ arguments.Add (new Argument (expr));
+ arguments.Add (new Argument (args));
+ return CreateExpressionFactoryCall ("Lambda",
+ new TypeArguments (loc, new TypeExpression (delegate_type, loc)),
+ arguments);
+ }
+
+ public override bool HasExplicitParameters {
+ get {
+ return explicit_parameters;
+ }
+ }
+
+ protected override Parameters ResolveParameters (EmitContext ec, TypeInferenceContext tic, Type delegateType)
{
- this.loc = loc;
+ if (!TypeManager.IsDelegateType (delegateType))
+ return null;
+
+ AParametersCollection d_params = TypeManager.GetDelegateParameters (delegateType);
+
+ if (explicit_parameters) {
+ if (!VerifyExplicitParameters (delegateType, d_params, ec.IsInProbingMode))
+ return null;
+
+ return Parameters;
+ }
+
+ //
+ // If L has an implicitly typed parameter list we make implicit parameters explicit
+ // Set each parameter of L is given the type of the corresponding parameter in D
+ //
+ if (!VerifyParameterCompatibility (delegateType, d_params, ec.IsInProbingMode))
+ return null;
+
+ Type [] ptypes = new Type [Parameters.Count];
+ for (int i = 0; i < d_params.Count; i++) {
+ // D has no ref or out parameters
+ if ((d_params.FixedParameters [i].ModFlags & Parameter.Modifier.ISBYREF) != 0)
+ return null;
+
+ Type d_param = d_params.Types [i];
+
+#if MS_COMPATIBLE
+ // Blablabla, because reflection does not work with dynamic types
+ if (d_param.IsGenericParameter)
+ d_param = delegateType.GetGenericArguments () [d_param.GenericParameterPosition];
+#endif
+ //
+ // When type inference context exists try to apply inferred type arguments
+ //
+ if (tic != null) {
+ d_param = tic.InflateGenericArgument (d_param);
+ }
+
+ ptypes [i] = d_param;
+ ((ImplicitLambdaParameter) Parameters.FixedParameters [i]).Type = d_param;
+ }
+
+ Parameters.Types = ptypes;
+ return Parameters;
}
public override Expression DoResolve (EmitContext ec)
{
- throw new NotImplementedException ();
+ //
+ // Only explicit parameters can be resolved at this point
+ //
+ if (explicit_parameters) {
+ if (!Parameters.Resolve (ec))
+ return null;
+ }
+
+ eclass = ExprClass.Value;
+ type = TypeManager.anonymous_method_type;
+ return this;
+ }
+
+ protected override AnonymousMethodBody CompatibleMethodFactory (Type returnType, Type delegateType, Parameters p, ToplevelBlock b)
+ {
+ return new LambdaMethod (p, b, returnType, delegateType, loc);
+ }
+
+ public override string GetSignatureForError ()
+ {
+ return "lambda expression";
+ }
+ }
+
+ public class LambdaMethod : AnonymousMethodBody
+ {
+ public LambdaMethod (Parameters parameters,
+ ToplevelBlock block, Type return_type, Type delegate_type,
+ Location loc)
+ : base (parameters, block, return_type, delegate_type, loc)
+ {
+ }
+
+ public override string ContainerType {
+ get {
+ return "lambda expression";
+ }
+ }
+
+ public override Expression CreateExpressionTree (EmitContext ec)
+ {
+ Expression args = parameters.CreateExpressionTree (ec, loc);
+ Expression expr = Block.CreateExpressionTree (ec);
+ if (expr == null)
+ return null;
+
+ ArrayList arguments = new ArrayList (2);
+ arguments.Add (new Argument (expr));
+ arguments.Add (new Argument (args));
+ return CreateExpressionFactoryCall ("Lambda",
+ new TypeArguments (loc, new TypeExpression (type, loc)),
+ arguments);
+ }
+ }
+
+ //
+ // This is a return statement that is prepended lambda expression bodies that happen
+ // to be expressions. Depending on the return type of the delegate this will behave
+ // as either { expr (); return (); } or { return expr (); }
+ //
+ public class ContextualReturn : Return
+ {
+ public ContextualReturn (Expression expr)
+ : base (expr, expr.Location)
+ {
+ }
+
+ public override Expression CreateExpressionTree (EmitContext ec)
+ {
+ return Expr.CreateExpressionTree (ec);
}
public override void Emit (EmitContext ec)
{
- throw new NotImplementedException ();
+ if (ec.ReturnType == TypeManager.void_type) {
+ ((ExpressionStatement) Expr).EmitStatement (ec);
+ ec.ig.Emit (OpCodes.Ret);
+ return;
+ }
+
+ base.Emit (ec);
+ }
+
+ protected override bool DoResolve (EmitContext ec)
+ {
+ //
+ // When delegate returns void, only expression statements can be used
+ //
+ if (ec.ReturnType == TypeManager.void_type) {
+ Expr = Expr.Resolve (ec);
+ if (Expr == null)
+ return false;
+
+ if (Expr is ExpressionStatement)
+ return true;
+
+ Expr.Error_InvalidExpressionStatement ();
+ return false;
+ }
+
+ return base.DoResolve (ec);
}
}
}
projects / mono.git / blobdiff