#include "stdafx.h"
#include "example.h"
#include "inp.h"
#include "lex.h"
#include "out.h"
#include <string>

using namespace std;

namespace experiment {

void PutStd (string s)
{
	PutStr (const_cast <char*> (s.c_str ()));
}

void PutLn (string s)
{
	PutStd (s);
	PutEol ();
}

string GetIdent ()
{
	string result = IdentVal;
	CheckSymbol (IDENT);
	return result;
}

string GetNumber ()
{
	string result = NumVal;
	CheckSymbol (NUM);
	return result;
}

string GetFloat ()
{
	string result = NumVal;
	CheckSymbol (FLT);
	return result;
}

string GetString ()
{
	string result = StrVal;
	CheckSymbol (STR);
	return result;
}

string GetChar ()
{
	string result = string (1, ChrVal);
	CheckSymbol (CHR);
	return result;
}

void mainExpression ();

void simpleExpression ()
{
	string value;

	if (sy == LPAR)
	{
		NextSymbol ();
		PutStd ("(");
		mainExpression ();
		PutStd (")");
		CheckSymbol (RPAR);
	}
	else
	{
		if (sy == IDENT)
			value = GetIdent ();
		else if (sy == NUM)
			value = GetNumber ();
		else if (sy == FLT)
			value = GetFloat ();
		else if (sy == STR)
			value = GetString ();
		else if (sy == CHR)
			value = GetChar ();
		else
			Error ("Expression expected"); // inp.h

	    PutStd (value);
	}
}

void mulExpression ()
{
	simpleExpression ();
	while (sy == ASTERISK || sy == SLASH)
	{
		if (sy == ASTERISK) PutStd ("*"); else  PutStd ("/");
		NextSymbol ();
  	    simpleExpression ();
	}
}

void addExpression ()
{
	mulExpression ();
	while (sy == PLUS || sy == MINUS)
	{
		if (sy == PLUS) PutStd ("+"); else  PutStd ("-");
		NextSymbol ();
  	    mulExpression ();
	}
}

void mainExpression ()
{ 
	PutStd ("[");
	addExpression ();
	PutStd ("]");
}

void expression ()
{ 
	PutStd ("expression ");
	mainExpression ();
	PutEol ();
}

/*
void addExpression1 ()
{
	simpleExpression ();
	if (sy == PLUS || sy == MINUS)
	{
	    NextSymbol ();
  	    addExpression1 ();
	}
}
*/

/*
void addExpression2 ()
{
	addExpression2 ();
	if (sy == PLUS || sy == MINUS)
	{
	    NextSymbol ();
  	    simpleExpression ();
	}
}
*/

void statement ();

void ifStatement ()
{
	PutLn ("if statement");
	Indent ();

	CheckSymbol (IF_);
	CheckSymbol (LPAR);
	expression ();
	CheckSymbol (RPAR);

	PutLn ("then statement");
	Indent ();
	statement ();
	Unindent ();

	if (sy == ELSE_)
	{
  	   PutLn ("else statement");
   	   CheckSymbol (ELSE_);
  	   Indent ();
  	   statement ();
   	   Unindent ();
	}

	Unindent ();
	PutLn ("end of if statement");
}

void compoundStatement ()
{
	CheckSymbol (LBRACE);
	PutLn ("compound statement");
	Indent ();

	while (sy != RBRACE)
	{
		statement ();
	}

	Unindent ();
	PutLn ("end of compound statement");
	CheckSymbol (RBRACE);
}

void simpleStatement ()
{
	PutLn ("simple statement");
	expression ();
    CheckSymbol (ASSIGN);
	expression ();
    CheckSymbol (SEMICOLON);
}

void statement ()
{
	if (sy == LBRACE)
		compoundStatement ();
	else if (sy == IF_)
		ifStatement ();
	else
		simpleStatement ();
}

void example ()
{
      while (sy!=EOS)
	  {
		  statement ();
	  }
}

} // end of namespace