/Dependencies/boo/src/Boo.Lang/Runtime/SliceDispatcherFactory.cs

#region license
// Copyright (c) 2003, 2004, 2005 Rodrigo B. de Oliveira (rbo@acm.org)
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without modification,
// are permitted provided that the following conditions are met:
// 
//     * Redistributions of source code must retain the above copyright notice,
//     this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright notice,
//     this list of conditions and the following disclaimer in the documentation
//     and/or other materials provided with the distribution.
//     * Neither the name of Rodrigo B. de Oliveira nor the names of its
//     contributors may be used to endorse or promote products derived from this
//     software without specific prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
// THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#endregion


using System;
using System.Reflection;

namespace Boo.Lang.Runtime
{
	class SliceDispatcherFactory : AbstractDispatcherFactory
	{
		public SliceDispatcherFactory(ExtensionRegistry extensions, object target, Type type, string name, params object[] arguments) : base(extensions, target, type, name == "" ? RuntimeServices.GetDefaultMemberName(type) : name, arguments)
		{
		}

		public Dispatcher CreateGetter()
		{
			MemberInfo member = ResolveMember();
			switch (member.MemberType)
			{
				case MemberTypes.Field:
				{	
					FieldInfo field = (FieldInfo)member;
					return
						delegate(object o, object[] arguments) { return RuntimeServices.GetSlice(field.GetValue(o), "", arguments); };
				}
				case MemberTypes.Property:
				{
					MethodInfo getter = ((PropertyInfo) member).GetGetMethod(true);
					if (null == getter) throw MissingField();

					if (getter.GetParameters().Length > 0) return EmitMethodDispatcher(getter);

					// TODO: remove the reflection invocation getter.Invoke from the path

					// otherwise its a simple property and the slice
					// should be applied to the return value
					return
						delegate(object o, object[] arguments) { return RuntimeServices.GetSlice(getter.Invoke(o, null), "", arguments); };
				}
				default:
				{
					throw MissingField();
				}
			}
		}

		private Dispatcher EmitMethodDispatcher(MethodInfo candidate)
		{
			CandidateMethod method = ResolveMethod(GetArgumentTypes(), new MethodInfo[] { candidate });
			if (null == method) throw MissingField();

			return new MethodDispatcherEmitter(_type, method, GetArgumentTypes()).Emit();
		}

		private MemberInfo ResolveMember()
		{
			MemberInfo[] candidates = _type.GetMember(_name, MemberTypes.Property | MemberTypes.Field, RuntimeServices.DefaultBindingFlags);
			if (candidates.Length == 0) throw MissingField();
			if (candidates.Length > 1) throw new AmbiguousMatchException(Builtins.join(candidates, ", "));

			return candidates[0];
		}

		public Dispatcher CreateSetter()
		{
			MemberInfo member = ResolveMember();
			switch (member.MemberType)
			{
				case MemberTypes.Field:
				{
					FieldInfo field = (FieldInfo)member;
					return
						delegate(object o, object[] arguments) { return RuntimeServices.SetSlice(field.GetValue(o), "", arguments); };
				}
				case MemberTypes.Property:
				{
					PropertyInfo property = (PropertyInfo)member;
					if (property.GetIndexParameters().Length > 0)
					{
						MethodInfo setter = property.GetSetMethod(true);
						if (null == setter) throw MissingField();
						return EmitMethodDispatcher(setter);
					}

					return delegate(object o, object[] arguments)
			       	{
			       		return RuntimeServices.SetSlice(RuntimeServices.GetProperty(o, _name), "", arguments);
			       	};
				}
				default:
				{
					throw MissingField();
				}
			}
		}
	}
}