https://github.com/thoughtspile/gaussik

A tiny js math parser: look, no trees!
https://github.com/thoughtspile/gaussik

Last synced: about 2 months ago
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A tiny js math parser: look, no trees!

• Host: GitHub
• URL: https://github.com/thoughtspile/gaussik
• Owner: thoughtspile
• Created: 2015-08-31T19:53:10.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2016-02-14T11:33:32.000Z (almost 9 years ago)
• Last Synced: 2023-12-13T03:00:58.070Z (about 1 year ago)
• Language: JavaScript
• Homepage:
• Size: 16.6 KB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# Gaussik is a tiny math parser

About 2K non-minified, non-gzipped. Processes the input string with regular expressions (not a single AST!) to allow calling math functions without object prefixes. Rewrites specified infix operators into function calls to allow for `x^y` exponentiation. Outputs a callable js function that runs almost as fast as native code. Highly configurable. Nice, minimal API. Runs in browser and in node.

## API guide

- __`parser(scope, infix)`__ creates a parser instance. Properties of the `scope` object can be accessed as globals in the input. Any `key` in `infix` object is converted into `infix[key](arg1, arg2)`. Returns a function. Both arguments are optional and default to empty objects. Examples:

```

var parseReal = parser(Math, {'^': 'pow'}); // usually you want this

var parseCos = parser({cos: Math.cos}, {});

var plainParse = parser();

var arithmParse = parser({}, {'^': pow});

```

- __`(expr, args)`__ converts `expr` string into a js function with argument order specified with `args`, an optional (no arguments assumed) comma-separated list or an array. Examples:

```

parseReal('(2 + x)^2 + sin(y)', 'x, y')

// --> function(x, y) { return Math.pow(2 + x, 2) + Math.sin(y); }

parseCos('cos(x) + Math.cos(x)', 'x');

// --> function(x) { return Math.cos(x) + Math.cos(x); }

plainParse('2 + 2');

// --> function() { return 2 + 2; }

```

## Disclaimers:

- _Garbage in -- garbage out._ No input validation. When an invalid string is supplied, the paser may crash on compilation. Wrap with try / catch.

- _Limited infix operator support._ All operators have the same precedence and are left-associative.

- _No default configuration._ See this API for useful setups.

- _(Almost) no sugar._ Processing only affects scoping and infix operators. `sin x` for function application and `x y` for product are invalid.

- _String literals may go wrong._ Processing also affects them.

- _Scoping rules imitate js._ Arguments override parser scope, parser scope overrides global scope.

- _Scope is stored by reference._ If it mutates, the functions use the new values. If properties are added or removed, things can go wrong. `Object.seal` suggested for scope object in ES5 environments.