|
1
|
|
|
<?php |
|
2
|
|
|
/* |
|
3
|
|
|
Copyright (c) 2016 Michal Čihař <[email protected]> |
|
4
|
|
|
|
|
5
|
|
|
This file is part of SimpleMath. |
|
6
|
|
|
|
|
7
|
|
|
This program is free software; you can redistribute it and/or modify |
|
8
|
|
|
it under the terms of the GNU General Public License as published by |
|
9
|
|
|
the Free Software Foundation; either version 2 of the License, or |
|
10
|
|
|
(at your option) any later version. |
|
11
|
|
|
|
|
12
|
|
|
This program is distributed in the hope that it will be useful, |
|
13
|
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of |
|
14
|
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
|
15
|
|
|
GNU General Public License for more details. |
|
16
|
|
|
|
|
17
|
|
|
You should have received a copy of the GNU General Public License along |
|
18
|
|
|
with this program; if not, write to the Free Software Foundation, Inc., |
|
19
|
|
|
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
|
20
|
|
|
*/ |
|
21
|
|
|
namespace SimpleMath; |
|
22
|
|
|
|
|
23
|
|
|
|
|
24
|
|
|
/** |
|
25
|
|
|
* Core class of the library performing parsing and calculations. |
|
26
|
|
|
*/ |
|
27
|
|
|
class Math { |
|
28
|
|
|
|
|
29
|
|
|
protected $variables = array(); |
|
30
|
|
|
protected $stack = null; |
|
31
|
|
|
|
|
32
|
|
|
/** |
|
33
|
|
|
* Parses and executes given formula |
|
34
|
|
|
* |
|
35
|
|
|
* @param string $string Formula to process |
|
36
|
|
|
* |
|
37
|
|
|
* @return int |
|
38
|
|
|
*/ |
|
39
|
|
|
public function evaluate($string) { |
|
40
|
|
|
$this->parse($string); |
|
41
|
|
|
return $this->run(); |
|
42
|
|
|
} |
|
43
|
|
|
|
|
44
|
|
|
/** |
|
45
|
|
|
* Parses given formula. The parsed formula is stored in |
|
46
|
|
|
* the class. |
|
47
|
|
|
* |
|
48
|
|
|
* @param string $string Formula to process |
|
49
|
|
|
* |
|
50
|
|
|
* @return void |
|
51
|
|
|
*/ |
|
52
|
|
|
public function parse($string) { |
|
53
|
|
|
$tokens = $this->tokenize($string); |
|
54
|
|
|
$output = new Stack(); |
|
55
|
|
|
$operators = new Stack(); |
|
56
|
|
|
foreach ($tokens as $token) { |
|
57
|
|
|
$expression = Expression::factory($token); |
|
58
|
|
|
if ($expression->isOperator()) { |
|
59
|
|
|
$this->parseOperator($expression, $output, $operators); |
|
60
|
|
|
} elseif ($expression->isParenthesis()) { |
|
61
|
|
|
$this->parseParenthesis($expression, $output, $operators); |
|
62
|
|
|
} else { |
|
63
|
|
|
$output->push($expression); |
|
64
|
|
|
} |
|
65
|
|
|
} |
|
66
|
|
|
while (($operator = $operators->pop())) { |
|
67
|
|
|
if ($operator->isParenthesis()) { |
|
68
|
|
|
throw new \RuntimeException('Mismatched Parenthesis'); |
|
69
|
|
|
} |
|
70
|
|
|
$output->push($operator); |
|
71
|
|
|
} |
|
72
|
|
|
$this->stack = $output; |
|
73
|
|
|
} |
|
74
|
|
|
|
|
75
|
|
|
/** |
|
76
|
|
|
* Registers variable for use withing calculation |
|
77
|
|
|
* |
|
78
|
|
|
* @param string $name Name of variable |
|
79
|
|
|
* @param int $value Value of variable |
|
80
|
|
|
* |
|
81
|
|
|
* @return void |
|
82
|
|
|
*/ |
|
83
|
|
|
public function registerVariable($name, $value) { |
|
84
|
|
|
$this->variables[$name] = $value; |
|
85
|
|
|
} |
|
86
|
|
|
|
|
87
|
|
|
/** |
|
88
|
|
|
* Executes currently parsed formula with current variables |
|
89
|
|
|
* |
|
90
|
|
|
* @return int |
|
91
|
|
|
*/ |
|
92
|
|
|
public function run() { |
|
93
|
|
|
$stack = clone $this->stack; |
|
94
|
|
|
while (($operator = $stack->pop()) && $operator->isOperator()) { |
|
95
|
|
|
$value = $operator->operate($stack, $this->variables); |
|
96
|
|
|
if (!is_null($value)) { |
|
97
|
|
|
$stack->push(Expression::factory($value)); |
|
98
|
|
|
} |
|
99
|
|
|
} |
|
100
|
|
|
return $operator->render(); |
|
101
|
|
|
} |
|
102
|
|
|
|
|
103
|
|
|
protected function parseParenthesis(Expression $expression, Stack $output, Stack $operators) { |
|
104
|
|
|
if ($expression->isOpen()) { |
|
105
|
|
|
$operators->push($expression); |
|
106
|
|
|
} else { |
|
107
|
|
|
$clean = false; |
|
108
|
|
|
while (($end = $operators->pop())) { |
|
109
|
|
|
if ($end->isParenthesis()) { |
|
110
|
|
|
$clean = true; |
|
111
|
|
|
break; |
|
112
|
|
|
} else { |
|
113
|
|
|
$output->push($end); |
|
114
|
|
|
} |
|
115
|
|
|
} |
|
116
|
|
|
if (!$clean) { |
|
117
|
|
|
throw new \RuntimeException('Mismatched Parenthesis'); |
|
118
|
|
|
} |
|
119
|
|
|
} |
|
120
|
|
|
} |
|
121
|
|
|
|
|
122
|
|
|
protected function parseOperator(Expression $expression, Stack $output, Stack $operators) { |
|
123
|
|
|
$end = $operators->poke(); |
|
124
|
|
|
if (!$end) { |
|
125
|
|
|
$operators->push($expression); |
|
126
|
|
|
} elseif ($end->isOperator()) { |
|
127
|
|
|
do { |
|
128
|
|
|
if ($expression->isLeftAssoc() && $expression->getPrecidence() <= $end->getPrecidence()) { |
|
129
|
|
|
$output->push($operators->pop()); |
|
130
|
|
|
} elseif (!$expression->isLeftAssoc() && $expression->getPrecidence() < $end->getPrecidence()) { |
|
131
|
|
|
$output->push($operators->pop()); |
|
132
|
|
|
} else { |
|
133
|
|
|
break; |
|
134
|
|
|
} |
|
135
|
|
|
} while (($end = $operators->poke()) && $end->isOperator()); |
|
136
|
|
|
$operators->push($expression); |
|
137
|
|
|
} else { |
|
138
|
|
|
$operators->push($expression); |
|
139
|
|
|
} |
|
140
|
|
|
} |
|
141
|
|
|
|
|
142
|
|
|
protected function tokenize($string) { |
|
143
|
|
|
$parts = preg_split( |
|
144
|
|
|
'(([0-9]*\.?[0-9]+|\+|-|\(|\)|\*|%|\/|:|\?|==|<=|>=|<|>|!=|&&|\|\|)|\s+)', |
|
145
|
|
|
$string, |
|
146
|
|
|
null, |
|
147
|
|
|
PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE |
|
148
|
|
|
); |
|
149
|
|
|
$parts = array_map('trim', $parts); |
|
150
|
|
|
return $parts; |
|
151
|
|
|
} |
|
152
|
|
|
|
|
153
|
|
|
} |
|
154
|
|
|
|
phpmyadmin /
simple-math
