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/*
* Copyright (c) 2016 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
* not be construed as granting a license to any other intellectual
* property including but not limited to intellectual property relating
* to a hardware implementation of the functionality of the software
* licensed hereunder. You may use the software subject to the license
* terms below provided that you ensure that this notice is replicated
* unmodified and in its entirety in all distributions of the software,
* modified or unmodified, in source code or in binary form.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: David Guillen Fandos
*/
#ifndef __SIM_MATHEXPR_HH__
#define __SIM_MATHEXPR_HH__
#include <algorithm>
#include <array>
#include <functional>
#include <string>
class MathExpr {
public:
MathExpr(std::string expr);
typedef std::function<double(std::string)> EvalCallback;
/**
* Prints an ASCII representation of the expression tree
*
* @return A string containing the ASCII representation of the expression
*/
std::string toStr() const { return toStr(root, ""); }
/**
* Evaluates the expression
*
* @param fn A callback funcion to evaluate variables
*
* @return The value for this expression
*/
double eval(EvalCallback fn) const { return eval(root, fn); }
private:
enum Operator {
bAdd, bSub, bMul, bDiv, bPow, uNeg, sValue, sVariable, nInvalid
};
// Match operators
const int MAX_PRIO = 4;
typedef double (*binOp)(double, double);
struct OpSearch {
bool binary;
Operator op;
int priority;
char c;
binOp fn;
};
/** Operator list */
std::array<OpSearch, uNeg + 1> ops;
class Node {
public:
Node() : op(nInvalid), l(0), r(0), value(0) {}
std::string toStr() const {
const char opStr[] = {'+', '-', '*', '/', '^', '-'};
switch (op) {
case nInvalid:
return "INVALID";
case sVariable:
return variable;
case sValue:
return std::to_string(value);
default:
return std::string(1, opStr[op]);
};
}
Operator op;
Node *l, *r;
double value;
std::string variable;
};
/** Root node */
Node * root;
/** Parse and create nodes from string */
Node *parse(std::string expr);
/** Print tree as string */
std::string toStr(Node *n, std::string prefix) const;
/** Eval a node */
double eval(const Node *n, EvalCallback fn) const;
};
#endif
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