Lico San
79 lines
2.7 KiB
Markdown
79 lines
2.7 KiB
Markdown
# Formula1
|
|
## Simple Mathematical formulas evaluator for PHP
|
|
|
|
If you need to evaluate a formula with basic operators and variables, and
|
|
|
|
* **No eval:** You dont want to use EVAL for obvious security reasons,
|
|
* **No dependencies:** You don't want to rely on half the internet as dependencies, but prefer a single self-contained class,
|
|
* **Old PHP OK:** You don't necessarily have the latest PHP version, or Composer,
|
|
* **No spaghetti:** You want something readable that you could easily understand and customize,
|
|
* **Arithmetic rules OK:** You need something that knows about operators priority, unary operators, and parenthesis,
|
|
* **Rounding OK:** You want to specify a precision and rounding mode for the result,
|
|
* **Recursive eval:** You want to be able to include sub-formulas inside your variables,
|
|
* **Arrays OK:** You need to use indexed or key-value arrays as variable inside the formula,
|
|
* **functions OK:** You need to use basic math functions inside the formula,
|
|
|
|
|
|
...then you gonna like Formula1 ! ;-)
|
|
|
|
|
|
|
|
**Simple usage no variables**
|
|
|
|
```PHP
|
|
$f1 = new Formula1('-45+(41*2)-(6/(3+1))');
|
|
echo($f1->compute()); // 35.5
|
|
```
|
|
|
|
```PHP
|
|
// With rounding (third and fourth params are precision and mode, like for the round function)
|
|
$f1 = new Formula1('2/3', [], 3);
|
|
echo($f1->compute()); // 0.667
|
|
```
|
|
|
|
**Simple usage with variables**
|
|
|
|
```PHP
|
|
$f1 = new Formula1('-45+(fourty_one*2)-(6/(three+1))' , ['fourty_one'=>41, 'three'=>3]);
|
|
echo($f1->compute()); // 35.5
|
|
```
|
|
|
|
**Funky usage with variables that include formulas themselves (and recusrively)**
|
|
|
|
```PHP
|
|
$f1 = new Formula1('-45+(fourty_one*2)-(6/(three+1))' , ['fourty_one'=>'82/2', 'three'=>'12/four', 'four'=>4]);
|
|
echo($f1->compute()); // 35.5
|
|
```
|
|
|
|
**Display parsing error if any**
|
|
|
|
```PHP
|
|
$f1 = new Formula1('-45+(fourty_one*2)-(6/(three+1)))' , ['fourty_one'=>'82/2', 'three'=>'12/four', 'four'=>4]);
|
|
if($f1->parse_error=='') echo($f1->compute());
|
|
else echo($f1->parse_error."<br>\n"); // Too many closing parenthesis !
|
|
```
|
|
|
|
**Use of a indexed array**
|
|
```PHP
|
|
$f1 = new Formula1('toto*primes[6]',['toto'=>10,'primes'=>[2,3,5,7,11,13,17,19,23,29,31]]);
|
|
echo($f1->compute()."<br>\n"); //170
|
|
```
|
|
|
|
**Use of a key-value array**
|
|
```PHP
|
|
$f1 = new Formula1('toto*myar["zorglub_99"]',['toto'=>10,'myar'=>['aaa'=>2.5,'zorglub_99'=>5.5]]);
|
|
echo($f1->compute()."<br>\n"); //55
|
|
```
|
|
|
|
|
|
**Use offunctions**
|
|
```PHP
|
|
$f1 = new Formula1('2*5+sin(pi()/4)');
|
|
echo($f1->compute()."<br>\n"); //7.071...
|
|
```
|
|
|
|
## TODO
|
|
|
|
* Would be better to give parameters in the compute, to allow one parsing-many evals, but needs rewrite of current parse-compute split.
|
|
* The index of indexed arrays should be evaluated to allow formulas as indexes, but needs rewrite of current parse-compute split.
|