/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.Collections.Generic;

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[] candidates = ResolveMember();

			if (candidates.Length == 1) return CreateGetter(candidates[0]);

			return EmitMethodDispatcher(Getters(candidates));

		}



		private IEnumerable<MethodInfo> Getters(MemberInfo[] candidates)

		{

			foreach (MemberInfo info in candidates)

			{

				PropertyInfo p = info as PropertyInfo;

				if (null == p) continue;

				MethodInfo getter = p.GetGetMethod(true);

				if (null == getter) continue;

				yield return getter;

			}

		}



		private Dispatcher CreateGetter(MemberInfo member)

		{

			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)

		{

			return EmitMethodDispatcher(new MethodInfo[] { candidate });

		}



		private Dispatcher EmitMethodDispatcher(IEnumerable<MethodInfo> candidates)

		{

			CandidateMethod method = ResolveMethod(GetArgumentTypes(), candidates);

			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();

			return candidates;

		}



		public Dispatcher CreateSetter()

		{

			MemberInfo[] candidates = ResolveMember();

			if (candidates.Length > 1) throw new AmbiguousMatchException(Builtins.join(candidates, ", "));

			return CreateSetter(candidates[0]);

		}



		private Dispatcher CreateSetter(MemberInfo member)

		{

			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();

					}

			}

		}

	}

}