colobot/src/CBot/CBotInstr/CBotWhile.cpp

153 lines
5.2 KiB
C++

/*
* This file is part of the Colobot: Gold Edition source code
* Copyright (C) 2001-2015, Daniel Roux, EPSITEC SA & TerranovaTeam
* http://epsitec.ch; http://colobot.info; http://github.com/colobot
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see http://gnu.org/licenses
*/
// Modules inlcude
#include "CBotWhile.h"
#include "CBotBlock.h"
#include "CBotCondition.h"
#include "CBotStack.h"
// Local include
// Global include
////////////////////////////////////////////////////////////////////////////////
CBotWhile::CBotWhile()
{
m_Condition =
m_Block = nullptr; // nullptr so that delete is not possible further
name = "CBotWhile"; // debug
}
////////////////////////////////////////////////////////////////////////////////
CBotWhile::~CBotWhile()
{
delete m_Condition; // frees the condition
delete m_Block; // releases the block instruction
}
////////////////////////////////////////////////////////////////////////////////
CBotInstr* CBotWhile::Compile(CBotToken* &p, CBotCStack* pStack)
{
CBotWhile* inst = new CBotWhile(); // creates the object
CBotToken* pp = p; // preserves at the ^ token (starting position)
if ( IsOfType( p, TokenTypVar ) &&
IsOfType( p, ID_DOTS ) )
{
inst->m_label = pp->GetString(); // records the name of the label
}
inst->SetToken(p);
if (!IsOfType(p, ID_WHILE)) return nullptr; // should never happen
CBotCStack* pStk = pStack->TokenStack(pp); // un petit bout de pile svp
// a bit of battery please (??)
if ( nullptr != (inst->m_Condition = CBotCondition::Compile( p, pStk )) )
{
// the condition exists
IncLvl(inst->m_label);
inst->m_Block = CBotBlock::CompileBlkOrInst( p, pStk, true );
DecLvl();
if ( pStk->IsOk() )
{
// the statement block is ok (it may be empty!
return pStack->Return(inst, pStk); // return an object to the application
// makes the object to which the application
}
}
delete inst; // error, frees the place
return pStack->Return(nullptr, pStk); // no object, the error is on the stack
}
////////////////////////////////////////////////////////////////////////////////
bool CBotWhile::Execute(CBotStack* &pj)
{
CBotStack* pile = pj->AddStack(this); // adds an item to the stack
// or find in case of recovery
// if ( pile == EOX ) return true;
if ( pile->IfStep() ) return false;
while( true ) switch( pile->GetState() ) // executes the loop
{ // there are two possible states (depending on recovery)
case 0:
// evaluates the condition
if ( !m_Condition->Execute(pile) ) return false; // interrupted here?
// the result of the condition is on the stack
// terminates if an error or if the condition is false
if ( !pile->IsOk() || pile->GetVal() != true )
{
return pj->Return(pile); // sends the results and releases the stack
}
// the condition is true, pass in the second mode
if (!pile->SetState(1)) return false; // ready for further
case 1:
// evaluates the associated statement block
if ( m_Block != nullptr &&
!m_Block->Execute(pile) )
{
if (pile->IfContinue(0, m_label)) continue; // if continued, will return to test
return pj->BreakReturn(pile, m_label); // sends the results and releases the stack
}
// terminates if there is an error
if ( !pile->IsOk() )
{
return pj->Return(pile); // sends the results and releases the stack
}
// returns to the test again
if (!pile->SetState(0, 0)) return false;
continue;
}
}
////////////////////////////////////////////////////////////////////////////////
void CBotWhile::RestoreState(CBotStack* &pj, bool bMain)
{
if ( !bMain ) return;
CBotStack* pile = pj->RestoreStack(this); // adds an item to the stack
if ( pile == nullptr ) return;
switch( pile->GetState() )
{ // there are two possible states (depending on recovery)
case 0:
// evaluates the condition
m_Condition->RestoreState(pile, bMain);
return;
case 1:
// evaluates the associated statement block
if ( m_Block != nullptr ) m_Block->RestoreState(pile, bMain);
return;
}
}