LuaFuncRef.h

/*
This file is part of the Lua_icxx library. 
Copyright 2010 (c) by Oliver Schoenborn. 
License terms in LICENSE.txt.
*/


#pragma once

#ifndef LUA_ICXX_FUNCREF_INCLUDED
#define LUA_ICXX_FUNCREF_INCLUDED


#include "LuaObjRef.h"
#include "LuaAdapters.h"
#include "luaFuncCalls.h"


class LuaFuncCallParams;
class LuaTableRef;


class LUA_ICXX_CPP_API
LuaFuncRef: public LuaObjRef
{
public: 
    explicit LuaFuncRef( const std::string& id = "nil" ): LuaObjRef(id) {}


    LuaFuncRef( const LuaTempResult& res): LuaObjRef(res) {}
    LuaFuncRef( const LuaTempResult::Item& item): LuaObjRef(item) {}
    LuaFuncRef( lua_State* lua, int stackPos ): LuaObjRef(lua, stackPos) {}

    bool setEnv(const LuaTableRef&);
    LuaTempResult getEnv() const;


    DECL_FN_CALLS(operator());
    DECL_FN_CALLS(call);

private: 
    inline LuaFuncCallParams prepCall() const;
};


class LUA_ICXX_CPP_API
LuaBoundMethRef
{
public:
    LuaBoundMethRef() {} // nil
    LuaBoundMethRef( const LuaObjRef & obj, const LuaFuncRef & fn )
        : mMethRef( fn ), mObjRef(obj) {}
    LuaBoundMethRef( const LuaTempResult & res )
        : mObjRef( res[1] ), mMethRef( res[2] ) {}


    void resetRef( const LuaObjRef & obj, const LuaFuncRef & fn );
    void resetRef( const LuaTempResult& result ) { resetRef(result[1], result[2]); }
    LuaBoundMethRef& operator=(const LuaTempResult& result )  { resetRef(result); return *this;}

    bool isNil() const { return mObjRef.isNil() || mMethRef.isNil(); }
    std::string typeName() const { return isNil() ? "nil" : "boundmethod"; }
    std::string getID() const { return mObjRef.getID() + ":" + mMethRef.getID(); }



    DECL_FN_CALLS(operator());
    DECL_FN_CALLS(call);

private:
    LuaObjRef   mObjRef;
    LuaFuncRef  mMethRef;
};


class LUA_ICXX_CPP_API
LuaClassObjRef: public LuaObjRef
{
public:
    explicit LuaClassObjRef( const std::string& id = "nil" ): LuaObjRef(id) {}

    LuaClassObjRef( const LuaTempResult& res): LuaObjRef(res) {}
    LuaClassObjRef( const LuaTempResult::Item& item): LuaObjRef(item) {}
    LuaClassObjRef( lua_State* lua, int stackPos ): LuaObjRef(lua, stackPos) {}

    LuaBoundMethRef getBoundMethod(const std::string&) const;



    DECL_FN_CALLS(callMethod);

private: 
    inline LuaFuncCallParams prepCall(const std::string&) const;
};


// ----------------------------------------------------------------------

template <typename TT>
struct NotAllowedAsFunctionArgument 
{ 
    static inline const TT& ref(const TT& obj) { return obj; } 
};

template <>
struct NotAllowedAsFunctionArgument<LuaTempResult>;

template <>
struct NotAllowedAsFunctionArgument<LuaTempResult::Item>;


/*  Puts the function call parameters on the Lua stack, makes the call, and 
    encapsulates the return values in a LuaTempResult. 
    */
class LUA_ICXX_CPP_API
LuaFuncCallParams
{
public:
    LuaFuncCallParams(const std::string& funcID, lua_State* lua, int currStackTop, 
        int alreadyOnStack = 0)
        : mFuncID(funcID.empty() ? "<anonymous>" : funcID), mLua(lua), 
        preStackTop(currStackTop), argsOnStack(alreadyOnStack) {}

public:
    template <typename TT>
    inline LuaFuncCallParams& operator<<(const TT& obj)
    { 
        pushValToStack(mLua, NotAllowedAsFunctionArgument<TT>::ref(obj));
        argsOnStack ++;
        return *this;
    }

    LuaTempResult doCall() const 
    {
        assert(mLua);
        const int numRets = LUA_MULTRET;
        const int errCode = lua_pcall(mLua, argsOnStack, numRets, 0);
        return LuaTempResult(mLua, preStackTop, errCode, "Function call " + mFuncID + "()");
    }

    // doesn't work: 
    //operator LuaTempResult() const 

private:
    lua_State * mLua;
    std::string mFuncID; 
    const int preStackTop;
    int argsOnStack;
};


inline LuaFuncCallParams 
LuaFuncRef::prepCall() 
const 
{
    const int curStackTop = (mLua ? lua_gettop(mLua) : 0);
    pushObj();
    return LuaFuncCallParams(getID(), mLua, curStackTop);
}


inline LuaFuncCallParams 
LuaClassObjRef::prepCall(const std::string& methName) 
const 
{
    const int curStackTop = (mLua ? lua_gettop(mLua) : 0);
    // get method of object:
    pushObj();
    lua_getfield(mLua, -1, methName.c_str());
    // move method before object since object must be first arg to function call: 
    lua_insert(mLua, -2);
    assert( lua_gettop(mLua) == curStackTop + 2 );
    return LuaFuncCallParams(getID(), mLua, curStackTop, 1);
}


// ----------- LuaFuncRef::call(...) and operator()(...) for 0 to 9 args of any type ------------------------

DEF_FN_CALL_0(LuaFuncRef::call,   prepCall().doCall() );
DEF_FN_CALL_1(LuaFuncRef::call, ( prepCall() << arg1 ).doCall() );
DEF_FN_CALL_2(LuaFuncRef::call, ( prepCall() << arg1 << arg2 ).doCall() );
DEF_FN_CALL_3(LuaFuncRef::call, ( prepCall() << arg1 << arg2 << arg3 ).doCall() );
DEF_FN_CALL_4(LuaFuncRef::call, ( prepCall() << arg1 << arg2 << arg3 << arg4 ).doCall() );
DEF_FN_CALL_5(LuaFuncRef::call, ( prepCall() << arg1 << arg2 << arg3 << arg4 << arg5 ).doCall() );
DEF_FN_CALL_6(LuaFuncRef::call, ( prepCall() << arg1 << arg2 << arg3 << arg4 << arg5 << arg6 ).doCall() );
DEF_FN_CALL_7(LuaFuncRef::call, ( prepCall() << arg1 << arg2 << arg3 << arg4 << arg5 << arg6 << arg7 ).doCall() );
DEF_FN_CALL_8(LuaFuncRef::call, ( prepCall() << arg1 << arg2 << arg3 << arg4 << arg5 << arg6 << arg7 << arg8 ).doCall() );
DEF_FN_CALL_9(LuaFuncRef::call, ( prepCall() << arg1 << arg2 << arg3 << arg4 << arg5 << arg6 << arg7 << arg8 << arg9 ).doCall() );

DEF_FN_CALL_0(LuaFuncRef::operator(), call() );
DEF_FN_CALL_1(LuaFuncRef::operator(), call(arg1) );
DEF_FN_CALL_2(LuaFuncRef::operator(), call(arg1, arg2 ) );
DEF_FN_CALL_3(LuaFuncRef::operator(), call(arg1, arg2, arg3 ) );
DEF_FN_CALL_4(LuaFuncRef::operator(), call(arg1, arg2, arg3, arg4 ) );
DEF_FN_CALL_5(LuaFuncRef::operator(), call(arg1, arg2, arg3, arg4, arg5 ) );
DEF_FN_CALL_6(LuaFuncRef::operator(), call(arg1, arg2, arg3, arg4, arg5, arg6 ) );
DEF_FN_CALL_7(LuaFuncRef::operator(), call(arg1, arg2, arg3, arg4, arg5, arg6, arg7 ) );
DEF_FN_CALL_8(LuaFuncRef::operator(), call(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8 ) );
DEF_FN_CALL_9(LuaFuncRef::operator(), call(arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9 ) );


// same for LuaBoundMethRef: 

DEF_FN_CALL_0(LuaBoundMethRef::call, mMethRef(mObjRef) );
DEF_FN_CALL_1(LuaBoundMethRef::call, mMethRef(mObjRef, arg1) );
DEF_FN_CALL_2(LuaBoundMethRef::call, mMethRef(mObjRef, arg1, arg2) );
DEF_FN_CALL_3(LuaBoundMethRef::call, mMethRef(mObjRef, arg1, arg2, arg3) );
DEF_FN_CALL_4(LuaBoundMethRef::call, mMethRef(mObjRef, arg1, arg2, arg3, arg4) );
DEF_FN_CALL_5(LuaBoundMethRef::call, mMethRef(mObjRef, arg1, arg2, arg3, arg4, arg5) );
DEF_FN_CALL_6(LuaBoundMethRef::call, mMethRef(mObjRef, arg1, arg2, arg3, arg4, arg5, arg6) );
DEF_FN_CALL_7(LuaBoundMethRef::call, mMethRef(mObjRef, arg1, arg2, arg3, arg4, arg5, arg6, arg7) );
DEF_FN_CALL_8(LuaBoundMethRef::call, mMethRef(mObjRef, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8) );
DEF_FN_CALL_9(LuaBoundMethRef::call, mMethRef(mObjRef, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9) );

DEF_FN_CALL_0(LuaBoundMethRef::operator(), call() );
DEF_FN_CALL_1(LuaBoundMethRef::operator(), call( arg1) );
DEF_FN_CALL_2(LuaBoundMethRef::operator(), call( arg1, arg2) );
DEF_FN_CALL_3(LuaBoundMethRef::operator(), call( arg1, arg2, arg3) );
DEF_FN_CALL_4(LuaBoundMethRef::operator(), call( arg1, arg2, arg3, arg4) );
DEF_FN_CALL_5(LuaBoundMethRef::operator(), call( arg1, arg2, arg3, arg4, arg5) );
DEF_FN_CALL_6(LuaBoundMethRef::operator(), call( arg1, arg2, arg3, arg4, arg5, arg6) );
DEF_FN_CALL_7(LuaBoundMethRef::operator(), call( arg1, arg2, arg3, arg4, arg5, arg6, arg7) );
DEF_FN_CALL_8(LuaBoundMethRef::operator(), call( arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8) );
DEF_FN_CALL_9(LuaBoundMethRef::operator(), call( arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9) );


// for LuaClassObjRef:

DEF_FN_CALL_1(LuaClassObjRef::callMethod, prepCall(arg1).doCall() );
DEF_FN_CALL_2(LuaClassObjRef::callMethod, ( prepCall(arg1) << arg2 ).doCall() );
DEF_FN_CALL_3(LuaClassObjRef::callMethod, ( prepCall(arg1) << arg2 << arg3 ).doCall() );
DEF_FN_CALL_4(LuaClassObjRef::callMethod, ( prepCall(arg1) << arg2 << arg3 << arg4 ).doCall() );
DEF_FN_CALL_5(LuaClassObjRef::callMethod, ( prepCall(arg1) << arg2 << arg3 << arg4 << arg5 ).doCall() );
DEF_FN_CALL_6(LuaClassObjRef::callMethod, ( prepCall(arg1) << arg2 << arg3 << arg4 << arg5 << arg6 ).doCall() );
DEF_FN_CALL_7(LuaClassObjRef::callMethod, ( prepCall(arg1) << arg2 << arg3 << arg4 << arg5 << arg6 << arg7 ).doCall() );
DEF_FN_CALL_8(LuaClassObjRef::callMethod, ( prepCall(arg1) << arg2 << arg3 << arg4 << arg5 << arg6 << arg7 << arg8 ).doCall() );
DEF_FN_CALL_9(LuaClassObjRef::callMethod, ( prepCall(arg1) << arg2 << arg3 << arg4 << arg5 << arg6 << arg7 << arg8 << arg9 ).doCall() );


#endif // LUA_ICXX_FUNCREF_INCLUDED