BEGIN LICENSE BLOCK *****
Version: EPL 2.0/GPL 2.0/LGPL 2.1
The contents of this file are subject to the Eclipse Public
License Version 2.0 (the "License"); you may not use this file
except in compliance with the License. You may obtain a copy of
the License at http://www.eclipse.org/legal/epl-v20.html
Software distributed under the License is distributed on an "AS
IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
implied. See the License for the specific language governing
rights and limitations under the License.
Copyright (C) 2001 Alan Moore 
Copyright (C) 2001-2002 Jan Arne Petersen 
Copyright (C) 2002 Anders Bengtsson 
Copyright (C) 2004 Charles O Nutter 
Copyright (C) 2004 Stefan Matthias Aust 
Alternatively, the contents of this file may be used under the terms of
either of the GNU General Public License Version 2 or later (the "GPL"),
or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
in which case the provisions of the GPL or the LGPL are applicable instead
of those above. If you wish to allow use of your version of this file only
under the terms of either the GPL or the LGPL, and not to allow others to
use your version of this file under the terms of the EPL, indicate your
decision by deleting the provisions above and replace them with the notice
and other provisions required by the GPL or the LGPL. If you do not delete
the provisions above, a recipient may use your version of this file under
the terms of any one of the EPL, the GPL or the LGPL.
END LICENSE BLOCK /***** BEGIN LICENSE BLOCK *****
 * Version: EPL 2.0/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Eclipse Public
 * License Version 2.0 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.eclipse.org/legal/epl-v20.html
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * Copyright (C) 2001 Alan Moore <alan_moore@gmx.net>
 * Copyright (C) 2001-2002 Jan Arne Petersen <jpetersen@uni-bonn.de>
 * Copyright (C) 2002 Anders Bengtsson <ndrsbngtssn@yahoo.se>
 * Copyright (C) 2004 Charles O Nutter <headius@headius.com>
 * Copyright (C) 2004 Stefan Matthias Aust <sma@3plus4.de>
 * 
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the EPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the EPL, the GPL or the LGPL.
 ***** END LICENSE BLOCK *****/

package org.jruby;

import org.jruby.anno.JRubyMethod;
import org.jruby.anno.JRubyClass;
import org.jruby.internal.runtime.methods.AliasMethod;
import org.jruby.internal.runtime.methods.DelegatingDynamicMethod;
import org.jruby.internal.runtime.methods.DynamicMethod;
import org.jruby.internal.runtime.methods.IRMethodArgs;
import org.jruby.internal.runtime.methods.ProcMethod;
import org.jruby.runtime.ArgumentDescriptor;
import org.jruby.runtime.Block;
import org.jruby.runtime.ClassIndex;
import org.jruby.runtime.Helpers;
import org.jruby.runtime.MethodBlockBody;
import org.jruby.runtime.ObjectAllocator;
import org.jruby.runtime.PositionAware;
import org.jruby.runtime.Signature;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.builtin.IRubyObject;
import org.jruby.runtime.callsite.CacheEntry;

The RubyMethod class represents a RubyMethod object.
You can get such a method by calling the "method" method of an object.
Note: This was renamed from Method.java
Author:
 jpetersen
Since:
0.2.3/** 
 * The RubyMethod class represents a RubyMethod object.
 * 
 * You can get such a method by calling the "method" method of an object.
 * 
 * Note: This was renamed from Method.java
 * 
 * @author  jpetersen
 * @since 0.2.3
 */
@JRubyClass(name="Method")
public class RubyMethod extends AbstractRubyMethod {
    protected IRubyObject receiver;

    protected RubyMethod(Ruby runtime, RubyClass rubyClass) {
        super(runtime, rubyClass);
    }

    
Create the RubyMethod class and add it to the Ruby runtime.
/** Create the RubyMethod class and add it to the Ruby runtime.
     * 
     */
    public static RubyClass createMethodClass(Ruby runtime) {
        // TODO: NOT_ALLOCATABLE_ALLOCATOR is probably ok here. Confirm. JRUBY-415
        RubyClass methodClass = runtime.defineClass("Method", runtime.getObject(), ObjectAllocator.NOT_ALLOCATABLE_ALLOCATOR);
        runtime.setMethod(methodClass);

        methodClass.setClassIndex(ClassIndex.METHOD);
        methodClass.setReifiedClass(RubyMethod.class);

        methodClass.defineAnnotatedMethods(AbstractRubyMethod.class);
        methodClass.defineAnnotatedMethods(RubyMethod.class);
        
        return methodClass;
    }

    public static RubyMethod newMethod(
        RubyModule implementationModule,
        String methodName,
        RubyModule originModule,
        String originName,
        CacheEntry entry,
        IRubyObject receiver) {
        Ruby runtime = implementationModule.getRuntime();
        RubyMethod newMethod = new RubyMethod(runtime, runtime.getMethod());

        newMethod.implementationModule = implementationModule;
        newMethod.methodName = methodName;
        newMethod.originModule = originModule;
        newMethod.originName = originName;
        newMethod.entry = entry;
        newMethod.method = entry.method;
        newMethod.sourceModule = entry.sourceModule;
        newMethod.receiver = receiver;

        return newMethod;
    }

    
Call the method.
/** Call the method.
     * 
     */
    @JRubyMethod(name = {"call", "[]"})
    public IRubyObject call(ThreadContext context, Block block) {
        return method.call(context, receiver, sourceModule, methodName, block);
    }
    @JRubyMethod(name = {"call", "[]"})
    public IRubyObject call(ThreadContext context, IRubyObject arg, Block block) {
        return method.call(context, receiver, sourceModule, methodName, arg, block);
    }
    @JRubyMethod(name = {"call", "[]"})
    public IRubyObject call(ThreadContext context, IRubyObject arg0, IRubyObject arg1, Block block) {
        return method.call(context, receiver, sourceModule, methodName, arg0, arg1, block);
    }
    @JRubyMethod(name = {"call", "[]"})
    public IRubyObject call(ThreadContext context, IRubyObject arg0, IRubyObject arg1, IRubyObject arg2, Block block) {
        return method.call(context, receiver, sourceModule, methodName, arg0, arg1, arg2, block);
    }
    @JRubyMethod(name = {"call", "[]"}, rest = true)
    public IRubyObject call(ThreadContext context, IRubyObject[] args, Block block) {
        return method.call(context, receiver, sourceModule, methodName, args, block);
    }

    
Returns the number of arguments a method accepted.
Returns:
the number of arguments of a method./** Returns the number of arguments a method accepted.
     * 
     * @return the number of arguments of a method.
     */
    @JRubyMethod
    public RubyFixnum arity() {
        int value;
        if (method instanceof IRMethodArgs) {
            value = ((IRMethodArgs) method).getSignature().arityValue();
        } else {
            value = method.getArity().getValue();
        }

        return getRuntime().newFixnum(value);
    }

    @JRubyMethod(name = "eql?", required = 1)
    public IRubyObject op_eql(ThreadContext context, IRubyObject other) {
        return op_equal(context, other);
    }

    @Override
    @JRubyMethod(name = "==", required = 1)
    public RubyBoolean op_equal(ThreadContext context, IRubyObject other) {
        return context.runtime.newBoolean( equals(other) );
    }

    @Override
    @JRubyMethod(name = "===", required = 1)
    public IRubyObject op_eqq(ThreadContext context, IRubyObject other) {
        return method.call(context, receiver, sourceModule, methodName, other, Block.NULL_BLOCK);
    }

    @Override
    public boolean equals(Object other) {
        if (!(other instanceof RubyMethod)) {
            return false;
        }
        if (method instanceof ProcMethod) {
            return ((ProcMethod) method).isSame(((RubyMethod) other).getMethod());
        }
        if (getMetaClass() != ((RubyBasicObject) other).getMetaClass()) {
            return false;
        }

        RubyMethod otherMethod = (RubyMethod)other;
        return receiver == otherMethod.receiver && originModule == otherMethod.originModule &&
            ( isSerialMatch(otherMethod.method) || isMethodMissingMatch(otherMethod.getMethod().getRealMethod()) );
    }

    private boolean isMethodMissingMatch(DynamicMethod other) {
        return (method.getRealMethod() instanceof RubyModule.RespondToMissingMethod) &&
                ((RubyModule.RespondToMissingMethod) method.getRealMethod()).equals(other);
    }

    private boolean isSerialMatch(DynamicMethod otherMethod) {
        return method.getRealMethod().getSerialNumber() == otherMethod.getRealMethod().getSerialNumber();
    }

    @JRubyMethod
    public RubyFixnum hash(ThreadContext context) {
        return context.runtime.newFixnum(hashCodeImpl());
    }

    @Override
    public int hashCode() {
        return (int) hashCodeImpl();
    }

    private long hashCodeImpl() {
        return receiver.hashCode() * method.getRealMethod().getSerialNumber();
    }

    @JRubyMethod(name = "clone")
    @Override
    public RubyMethod rbClone() {
        RubyMethod newMethod = newMethod(implementationModule, methodName, originModule, originName, entry, receiver);
        newMethod.setMetaClass(getMetaClass());
        return newMethod;
    }

    
Create a Proc object.
/** Create a Proc object.
     * 
     */
    @JRubyMethod
    public IRubyObject to_proc(ThreadContext context) {
        Ruby runtime = context.runtime;

        MethodBlockBody body;
        Signature signature;
        ArgumentDescriptor[] argsDesc;
        if (method instanceof IRMethodArgs) {
            signature = ((IRMethodArgs) method).getSignature();
            argsDesc = ((IRMethodArgs) method).getArgumentDescriptors();
        } else {
            signature = Signature.from(method.getArity());
            argsDesc = Helpers.methodToArgumentDescriptors(method);
        }

        int line = getLine(); // getLine adds 1 to 1-index but we need to reset to 0-index internally
        body = new MethodBlockBody(runtime.getStaticScopeFactory().getDummyScope(), signature, entry, argsDesc,
                receiver, originModule, originName, getFilename(), line == -1 ? -1 : line - 1);
        Block b = MethodBlockBody.createMethodBlock(body);
        
        return RubyProc.newProc(runtime, b, Block.Type.LAMBDA);
    }

    @JRubyMethod
    public RubyUnboundMethod unbind() {
        RubyUnboundMethod unboundMethod =
        	RubyUnboundMethod.newUnboundMethod(implementationModule, methodName, originModule, originName, entry);
        unboundMethod.infectBy(this);
        
        return unboundMethod;
    }
    
    @JRubyMethod(name = {"inspect", "to_s"})
    @Override
    public IRubyObject inspect() {
        Ruby runtime = getRuntime();
        ThreadContext context = runtime.getCurrentContext();

        RubyString str = RubyString.newString(runtime, "#<");
        String sharp = "#";
        
        str.catString(getType().getName()).catString(": ");

        RubyModule definedClass;
        RubyModule mklass = originModule;

        if (method instanceof AliasMethod || method instanceof DelegatingDynamicMethod) {
            definedClass = method.getRealMethod().getDefinedClass();
        }
        else {
            definedClass = method.getDefinedClass();
        }

        if (definedClass.isIncluded()) {
            definedClass = definedClass.getMetaClass();
        }

        if (mklass.isSingleton()) {
            IRubyObject attached = ((MetaClass) mklass).getAttached();
            if (receiver == null) {
                str.cat19(inspect(context, mklass).convertToString());
            } else if (receiver == attached) {
                str.cat19(inspect(context, attached).convertToString());
                sharp = ".";
            } else {
                str.cat19(inspect(context, receiver).convertToString());
                str.catString("(");
                str.cat19(inspect(context, attached).convertToString());
                str.catString(")");
                sharp = ".";
            }
        } else {
            str.catString(mklass.getName());
            if (definedClass != mklass) {
                str.catString("(");
                str.catString(definedClass.getName());
                str.catString(")");
            }
        }
        str.catString(sharp);
        str.catString(this.methodName);
        if (!methodName.equals(method.getName())) {
            str.catString("(");
            str.catString(method.getName());
            str.catString(")");
        }
        if (method.isNotImplemented()) {
            str.catString(" (not-implemented)");
        }
        str.catString(">");

        return str;
    }

    @JRubyMethod
    public IRubyObject receiver(ThreadContext context) {
        return receiver;
    }

    @JRubyMethod
    public IRubyObject source_location(ThreadContext context) {
        Ruby runtime = context.runtime;

        String filename = getFilename();
        if (filename != null) {
            return runtime.newArray(runtime.newString(filename), runtime.newFixnum(getLine()));
        }

        return context.nil;
    }

    public String getFilename() {
        DynamicMethod realMethod = method.getRealMethod(); // Follow Aliases
        if (realMethod instanceof PositionAware) {
            PositionAware poser = (PositionAware) realMethod;
            return poser.getFile();
        }
        return null;
    }

    public int getLine() {
        DynamicMethod realMethod = method.getRealMethod(); // Follow Aliases
        if (realMethod instanceof PositionAware) {
            PositionAware poser = (PositionAware) realMethod;
            return poser.getLine() + 1;
        }
        return -1;
    }

    @JRubyMethod
    public IRubyObject parameters(ThreadContext context) {
        return Helpers.methodToParameters(context.runtime, this);
    }

    @JRubyMethod(optional = 1)
    public IRubyObject curry(ThreadContext context, IRubyObject[] args) {
        return to_proc(context).callMethod(context, "curry", args);
    }

    @JRubyMethod
    public IRubyObject super_method(ThreadContext context) {
        return super_method(context, receiver, sourceModule.getSuperClass());
    }

    @JRubyMethod
    public IRubyObject original_name(ThreadContext context) {
        if (method instanceof AliasMethod) {
            return context.runtime.newSymbol(((AliasMethod)method).getOldName());
        }
        return name(context);
    }

}