1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
|
# MathExecutor [](https://github.com/neonxp/MathExecutor/actions?query=workflow%3ATests)
# A simple and extensible math expressions calculator
## Features:
* Built in support for +, -, *, / and power (^) operators plus ()
* Logical operators (==, !=, <, <, >=, <=, &&, ||)
* Built in support for most PHP math functions
* Conditional If logic
* Support for user defined operators
* Support for user defined functions
* Support for math on user defined objects
* Dynamic variable resolution (delayed computation)
* Unlimited variable name lengths
* String support, as function parameters or as evaluated as a number by PHP
* Exceptions on divide by zero, or treat as zero
* Unary Plus and Minus (e.g. +3 or -sin(12))
* Pi ($pi) and Euler's number ($e) support to 11 decimal places
* Easily extensible
## Install via Composer:
```
composer require nxp/math-executor
```
## Sample usage:
```php
use NXP\MathExecutor;
$executor = new MathExecutor();
echo $executor->execute('1 + 2 * (2 - (4+10))^2 + sin(10)');
```
## Functions:
Default functions:
* abs
* acos (arccos)
* acosh
* arcctg (arccot, arccotan)
* arcsec
* arccsc (arccosec)
* asin (arcsin)
* atan (atn, arctan, arctg)
* atan2
* atanh
* avg
* bindec
* ceil
* cos
* cosec (csc)
* cosh
* ctg (cot, cotan, cotg, ctn)
* decbin
* dechex
* decoct
* deg2rad
* exp
* expm1
* floor
* fmod
* hexdec
* hypot
* if
* intdiv
* log (ln)
* log10 (lg)
* log1p
* max
* min
* octdec
* pi
* pow
* rad2deg
* round
* sec
* sin
* sinh
* sqrt
* tan (tn, tg)
* tanh
Add custom function to executor:
```php
$executor->addFunction('abs', function($arg) {return abs($arg);});
```
Function default parameters are not supported at this time.
## Operators:
Default operators: `+ - * / ^`
Add custom operator to executor:
```php
use NXP\Classes\Operator;
$executor->addOperator(new Operator(
'%', // Operator sign
false, // Is right associated operator
170, // Operator priority
function (&$stack)
{
$op2 = array_pop($stack);
$op1 = array_pop($stack);
$result = $op1->getValue() % $op2->getValue();
return $result;
}
));
```
## Logical operators:
Logical operators (==, !=, <, <, >=, <=, &&, ||) are supported, but logically they can only return true (1) or false (0). In order to leverage them, use the built in **if** function:
```
if($a > $b, $a - $b, $b - $a)
```
You can think of the **if** function as prototyped like:
```
function if($condition, $returnIfTrue, $returnIfFalse)
```
## Variables:
Variables can be prefixed with the dollar sign ($) for PHP compatibility, but is not required.
Default variables:
```
$pi = 3.14159265359
$e = 2.71828182846
```
You can add your own variables to executor:
```php
$executor->setVar('var1', 0.15)->setVar('var2', 0.22);
echo $executor->execute("$var1 + var2");
```
By default, variables must be scalar values (int, float, bool or string). If you would like to support another type, use **setVarValidationHandler**
```php
$executor->setVarValidationHandler(function (string $name, $variable) {
// allow all scalars and null
if (is_scalar($variable) || $variable === null) {
return;
}
// Allow variables of type DateTime, but not others
if (! $variable instanceof \DateTime) {
throw new MathExecutorException("Invalid variable type");
}
});
```
You can dynamically define variables at run time. If a variable has a high computation cost, but might not be used, then you can define an undefined variable handler. It will only get called when the variable is used, rather than having to always set it initially.
```php
$calculator = new MathExecutor();
$calculator->setVarNotFoundHandler(
function ($varName) {
if ($varName == 'trans') {
return transmogrify();
}
return null;
}
);
```
## Division By Zero Support:
Division by zero throws a `\NXP\Exception\DivisionByZeroException` by default
```php
try {
echo $executor->execute('1/0');
} catch (DivisionByZeroException $e) {
echo $e->getMessage();
}
```
Or call setDivisionByZeroIsZero
```php
echo $executor->setDivisionByZeroIsZero()->execute('1/0');
```
If you want another behavior, you can override division operator:
```php
$executor->addOperator("/", false, 180, function($a, $b) {
if ($b == 0) {
return null;
}
return $a / $b;
});
echo $executor->execute('1/0');
```
## String Support:
Expressions can contain double or single quoted strings that are evaluated the same way as PHP evalutes strings as numbers. You can also pass strings to functions.
```php
echo $executor->execute("1 + '2.5' * '.5' + myFunction('category')");
```
## Extending MathExecutor
You can add operators, functions and variables with the public methods in MathExecutor, but if you need to do more serious modifications to base behaviours, the easiest way to extend MathExecutor is to redefine the following methods in your derived class:
* defaultOperators
* defaultFunctions
* defaultVars
This will allow you to remove functions and operators if needed, or implement different types more simply.
Also note that you can replace an existing default operator by adding a new operator with the same regular expression string. For example if you just need to redefine TokenPlus, you can just add a new operator with the same regex string, in this case '\\+'.
## Documentation
Full class documentation via [PHPFUI/InstaDoc](http://phpfui.com/?n=NXP&c=MathExecutor)
## Future Enhancements
This package will continue to track currently supported versions of PHP.
|
