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livetrax/libs/canvas/kiwi/expression.h

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/*-----------------------------------------------------------------------------
| Copyright (c) 2013-2017, Nucleic Development Team.
|
| Distributed under the terms of the Modified BSD License.
|
| The full license is in the file LICENSE, distributed with this software.
|----------------------------------------------------------------------------*/
#pragma once
#include <ostream>
#include <vector>
#include "term.h"
namespace kiwi
{
class Expression
{
public:
Expression(double constant = 0.0) : m_constant(constant) {}
Expression(const Term &term, double constant = 0.0) : m_terms(1, term), m_constant(constant) {}
Expression(const std::vector<Term> &terms, double constant = 0.0) : m_terms(terms), m_constant(constant) {}
~Expression() {}
const std::vector<Term> &terms() const
{
return m_terms;
}
double constant() const
{
return m_constant;
}
double value() const
{
typedef std::vector<Term>::const_iterator iter_t;
double result = m_constant;
iter_t end = m_terms.end();
for (iter_t it = m_terms.begin(); it != end; ++it)
result += it->value();
return result;
}
bool involves (Variable const & v) const {
for (std::vector<Term>::const_iterator it = m_terms.begin(); it != m_terms.end(); ++it) {
if (it->variable().equals (v)) {
return true;
}
}
return false;
}
private:
std::vector<Term> m_terms;
double m_constant;
};
static std::ostream& operator<<(std::ostream& o, kiwi::Expression const &e)
{
o << e.constant() << " + ";
for (std::vector<kiwi::Term>::const_iterator it = e.terms().begin(); it != e.terms().end(); ++it) {
o << (*it) << ' ';
}
return o;
}
} // namespace kiwi