Thread: #define question

I have put it like this now. So I have put void Help() outside the button control event handler but this does not either compile :\. Am I doing it wrong.

Code:

private: System::Void button1_Click(System::Object^  sender, System::EventArgs^  e) 
{
			 
bool ParseIf(const std::string& strToParse);
bool OperationEqual(const std::string& strToParse, const std::string& strVariable);
std::map<std::string, bool (*)(const std::string&)> ParseMap;
std::map<std::string, bool (*)(const std::string&, const std::string&)> ParseMap2;
std::map<std::string, long> VariablesMap;
}

	void Help()
	{


	ParseMap["if"] = &ParseIf;
	ParseMap2["=="] = &OperationEqual;
	VariablesMap["Number1"] = 1;

	std::string strToParse = "if (Number1 == 1)";
	std::string::size_type index = strToParse.find(" ");
	std::string strKeyword = strToParse.substr(0, index);
	if ( ParseMap.find( strKeyword.c_str() )->second( strToParse.substr(index + 1) ) )
	; // The if evaluated to true; execute action underneath the if
	else
	; // The if evaluated to false; skip everything underneath the if
	}

I have put it excatly like you did above but this does not either compile.

Yes ofcourse. I get these errors:

Code:

error C2039: 'ParseMap' : is not a member of 'std'
error C2535: 'void Form2::Form1::Help(void)' : member function already defined or declared see declaration of 'Form2::Form1::Help'
error C4368: cannot define 'ParseMap' as a member of managed 'Form2::Form1': mixed types are not supported
error C4368: cannot define 'ParseMap2' as a member of managed 'Form2::Form1': mixed types are not supported
error C4368: cannot define 'VariablesMap' as a member of managed 'Form2::Form1': mixed types are not supported
error C2678: binary '[' : no operator found which takes a left-hand operand of type 'std::map<_Kty,_Ty>' (or there is no acceptable conversion)

I dont really get it to compile anyway.
I think it would be better for me perheps to buy a book about interpreters as it is kind of complex if you dont know the basics of this like me

I would be interested about any tips if any of sites or books.
I did found this link: It sounds to be something to start with.
http://www.amazon.com/gp/product/047...r_dp_orig_subj

Yes you are probably right. I have put this only to native now like this and have only a few errors.

If I // these 4 lines like this, it will compile. Is something missing for what I have done.

// bool ParseIf(const std::string& strToParse);
// bool OperationEqual(const std::string& strToParse, const std::string& strVariable);
// ParseMap["if"] = &ParseIf;
// ParseMap2["=="] = &OperationEqual;

Code:

#pragma once
#include "stdafx.h"
#include <iostream>
#include <fstream>
#include <sstream> 
#include <string>  
#include <vector>
#include <cmath>
#include <algorithm>
#include <limits>
#include <ios>
#include <cstdio>
#include <map>

using namespace System;

void Help();



int main(array<System::String ^> ^args)
{
    Help();

    return 0;
}

bool ParseIf(const std::string& strToParse);
bool OperationEqual(const std::string& strToParse, const std::string& strVariable);
std::map<std::string, bool (*)(const std::string&)> ParseMap;
std::map<std::string, bool (*)(const std::string&, const std::string&)> ParseMap2;
std::map<std::string, long> VariablesMap;



void Help()
{
	ParseMap["if"] = &ParseIf;
	ParseMap2["=="] = &OperationEqual;
	VariablesMap["Number1"] = 1;

	std::string strToParse = "if (Number1 == 1)";
	std::string::size_type index = strToParse.find(" ");
	std::string strKeyword = strToParse.substr(0, index);
	if ( ParseMap.find( strKeyword.c_str() )->second( strToParse.substr(index + 1) ) )
		; // The if evaluated to true; execute action underneath the if
	else
		; // The if evaluated to false; skip everything underneath the if
}

I think I have put it right now as above but with int main() etc... I get these compile errors.

Anyway I think I will wait with writing an interpreter, because I dont really understand the whole process of how this is working. It is to difficult for me I think right now.
My picture that I get is that it is very difficult. Is it ?
Perheps it will be more easy when I understand exactly how the interpreter works.
I dont do that now. Like from step 1 to 10 and here a book maybe is a good idéa.

Code:

error LNK2019: unresolved external symbol "bool __cdecl OperationEqual(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" (?OperationEqual@@YA_NABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@0@Z) referenced in function "void __cdecl Help(void)" (?Help@@YAXXZ)
error LNK2019: unresolved external symbol "bool __cdecl ParseIf(class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &)" (?ParseIf@@YA_NABV?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@@Z) referenced in function "void __cdecl Help(void)" (?Help@@YAXXZ)
fatal error LNK1120: 2 unresolved externals