time-to-botec/squiggle/node_modules/@stdlib/assert/is-safe-integer/README.md

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@license Apache-2.0
Copyright (c) 2018 The Stdlib Authors.
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# isSafeInteger
> Test if a value is a number having a safe integer value.
<section class="usage">
## Usage
```javascript
var isSafeInteger = require( '@stdlib/assert/is-safe-integer' );
```
#### isSafeInteger( value )
Tests if a value is a `number` having a safe `integer` value.
<!-- eslint-disable no-new-wrappers -->
```javascript
var Number = require( '@stdlib/number/ctor' );
var bool = isSafeInteger( 5.0 );
// returns true
bool = isSafeInteger( new Number( 5.0 ) );
// returns true
bool = isSafeInteger( 2.0e200 );
// returns false
bool = isSafeInteger( -3.14 );
// returns false
bool = isSafeInteger( null );
// returns false
```
#### isSafeInteger.isPrimitive( value )
Tests if a `value` is a primitive `number` having a safe `integer` value.
<!-- eslint-disable no-new-wrappers -->
```javascript
var Number = require( '@stdlib/number/ctor' );
var bool = isSafeInteger.isPrimitive( -3.0 );
// returns true
bool = isSafeInteger.isPrimitive( new Number( -3.0 ) );
// returns false
```
#### isSafeInteger.isObject( value )
Tests if a `value` is a `Number` object having a safe `integer` value.
<!-- eslint-disable no-new-wrappers -->
```javascript
var Number = require( '@stdlib/number/ctor' );
var bool = isSafeInteger.isObject( 3.0 );
// returns false
bool = isSafeInteger.isObject( new Number( 3.0 ) );
// returns true
```
</section>
<!-- /.usage -->
<section class="notes">
## Notes
- An integer valued number is "safe" when the number can be exactly represented as a [double-precision floating-point number][ieee754]. For example,
```javascript
var MAX_SAFE_INTEGER = require( '@stdlib/constants/float64/max-safe-integer' );
// returns 9007199254740991
var x = 9007199254740992;
// returns 9007199254740992
var y = 9007199254740993;
// returns 9007199254740992
var bool = ( x === y );
// returns true
```
In this example, `x` and `y` should be distinct, but they are not due to constraints imposed by storing numeric values in [double-precision floating-point format][ieee754]. "Safe" integers are thus [double-precision floating-point numbers][ieee754] having integer values with unequivocal binary representations.
</section>
<!-- /.notes -->
<section class="examples">
## Examples
<!-- eslint-disable no-new-wrappers -->
<!-- eslint no-undef: "error" -->
```javascript
var Number = require( '@stdlib/number/ctor' );
var isSafeInteger = require( '@stdlib/assert/is-safe-integer' );
var bool = isSafeInteger( -5.0 );
// returns true
bool = isSafeInteger( 0.0 );
// returns true
bool = isSafeInteger( new Number( 5.0 ) );
// returns true
bool = isSafeInteger( 2.0e200 );
// returns false
bool = isSafeInteger( 5.256 );
// returns false
bool = isSafeInteger( 1.0/0.0 );
// returns false
bool = isSafeInteger( -1.0/0.0 );
// returns false
bool = isSafeInteger( NaN );
// returns false
bool = isSafeInteger( '5' );
// returns false
bool = isSafeInteger( null );
// returns false
```
</section>
<!-- /.examples -->
<section class="links">
[ieee754]: https://en.wikipedia.org/wiki/IEEE_754-1985
</section>
<!-- /.links -->