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/***************************************************************************
* Copyright (C) 2004-2005 by Daniel Clarke *
* [email protected] *
* *
* 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 2 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, write to the *
* Free Software Foundation, Inc., *
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. *
***************************************************************************/
#include "btreebase.h"
#include "traverser.h"
#include "parser.h"
#include "pic14.h"
BTreeBase::BTreeBase()
{
m_root = 0L;
}
void BTreeBase::deleteTree()
{
if(m_root) m_root->deleteChildren();
delete m_root;
m_root = 0L;
}
BTreeBase::~BTreeBase()
{
deleteTree();
}
void BTreeBase::addNode(BTreeNode *parent, BTreeNode *node, bool left)
{
// Debugging lines, remove when expression parsing has been completed.
//if(!parent) cerr<<"Null parent pointer!\n";
//if(!node) cerr<<"Null node pointer!\n");
if(left) parent->setLeft(node);
else parent->setRight(node);
}
void BTreeBase::pruneTree(BTreeNode *root, bool /*conditionalRoot*/)
{
Traverser t(root);
t.descendLeftwardToTerminal();
bool done = false;
while(!done)
{
//t.descendLeftwardToTerminal();
if( t.current()->parent() )
{
if( t.oppositeNode()->hasChildren() ) pruneTree(t.oppositeNode());
}
t.moveToParent();
if( !t.current()->hasChildren() )
{
//if(t.current() == t.root()) done = true;
if(!t.current()->parent()) done = true;
continue;
}
BTreeNode *l = t.current()->left();
BTreeNode *r = t.current()->right();
BTreeNode *n = 0;
BTreeNode *z = 0;
// Deal with situations where there are two constants so we want
// to evaluate at compile time
if( (l->type() == number && r->type() == number) ) // && !(t.current()==root&&conditionalRoot) )
{
if(t.current()->childOp() == Expression::division && r->value() == "0" )
{
t.current()->setChildOp(Expression::divbyzero);
return;
}
QString value = QString::number(Parser::doArithmetic(l->value().toInt(),r->value().toInt(),t.current()->childOp()));
t.current()->deleteChildren();
t.current()->setChildOp(Expression::noop);
t.current()->setType(number);
t.current()->setValue(value);
}
// Addition and subtraction
else if(t.current()->childOp() == Expression::addition || t.current()->childOp() == Expression::subtraction)
{
// See if one of the nodes is 0, and set n to the node that actually has data,
// z to the one containing zero.
bool zero = false;
if( l->value() == "0" )
{
zero = true;
n = r;
z = l;
}
else if( r->value() == "0" )
{
zero = true;
n = l;
z = r;
}
// Now get rid of the useless nodes
if(zero)
{
BTreeNode *p = t.current(); // save in order to delete after
replaceNode(p,n);
t.setCurrent(n);
// Delete the old nodes
delete p;
delete z;
}
}
// Multiplication and division
else if(t.current()->childOp() == Expression::multiplication || t.current()->childOp() == Expression::division)
{
// See if one of the nodes is 0, and set n to the node that actually has data,
// z to the one containing zero.
bool zero = false;
bool one = false;
if( l->value() == "1" )
{
one = true;
n = r;
z = l;
}
else if( r->value() == "1" )
{
one = true;
n = l;
z = r;
}
if( l->value() == "0" )
{
zero = true;
n = r;
z = l;
}
else if( r->value() == "0" )
{
// since we can't call compileError from in this class, we have a special way of handling it:
// Leave the children as they are, and set childOp to divbyzero
if( t.current()->childOp() == Expression::division )
{
t.current()->setChildOp(Expression::divbyzero);
return; // no point doing any more since we are going to raise a compileError later anyway.
}
zero = true;
n = l;
z = r;
}
// Now get rid of the useless nodes
if(one)
{
BTreeNode *p = t.current(); // save in order to delete after
replaceNode(p,n);
t.setCurrent(n);
// Delete the old nodes
delete p;
delete z;
}
if(zero)
{
BTreeNode *p = t.current();
p->deleteChildren();
p->setChildOp(Expression::noop);
p->setType(number);
p->setValue("0");
}
}
else if( t.current()->childOp() == Expression::bwand || t.current()->childOp() == Expression::bwor || t.current()->childOp() == Expression::bwxor )
{
bool zero = false;
if( l->value() == "0" )
{
zero = true;
n = r;
z = l;
}
else if( r->value() == "0" )
{
zero = true;
n = l;
z = r;
}
// Now get rid of the useless nodes
if(zero)
{
BTreeNode *p = t.current();
QString value;
if( p->childOp() == Expression::bwand )
{
value = "0";
p->deleteChildren();
p->setChildOp(Expression::noop);
p->setType(number);
}
if( p->childOp() == Expression::bwor || p->childOp() == Expression::bwxor )
{
value = n->value();
BTreeNode *p = t.current(); // save in order to delete after
replaceNode(p,n);
t.setCurrent(n);
// Delete the old nodes
delete p;
delete z;
}
p->setValue(value);
}
}
if(!t.current()->parent() || t.current() == root) done = true;
else
{
}
}
}
void BTreeBase::replaceNode(BTreeNode *node, BTreeNode *replacement)
{
// (This works under the assumption that a node is not linked to two places at once).
if( !node->parent() )
{
setRoot(replacement);
replacement->setParent(0L);
return;
}
if( node->parent()->left() == node ) node->parent()->setLeft(replacement);
if( node->parent()->right() == node ) node->parent()->setRight(replacement);
}
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