Slice

Slice constructor.

Installation

npm install @stdlib/slice-ctor

Usage

var Slice = require( '@stdlib/slice-ctor' );

Slice( [stop] )

Returns a Slice instance.

var s = new Slice();
// returns <Slice>

s = new Slice();
// returns <Slice>

The constructor accepts the following arguments:

• stop: ending index (exclusive). Default: null.

Slice( start, stop[, step] )

Returns a Slice instance.

var s = new Slice( 0, 10 );
// returns <Slice>

s = new Slice( 0, 10, 1 );
// returns <Slice>

The constructor accepts the following arguments:

• start: starting index (inclusive).
• stop: ending index (exclusive).
• step: index increment. A numeric index increment argument must be a non-zero integer value. Default: null.

Properties

Slice.name

String value of the Slice constructor name.

var str = Slice.name;
// returns 'Slice'

Slice.prototype.start

Read-only property returning the slice starting index.

var s = new Slice( 10 );
// returns <Slice>

var start = s.start;
// returns null

s = new Slice( 2, 10 );
// returns <Slice>

start = s.start;
// returns 2

Slice.prototype.stop

Read-only property returning the slice ending index.

var s = new Slice( null );
// returns <Slice>

var stop = s.stop;
// returns null

s = new Slice( 10 );
// returns <Slice>

stop = s.stop;
// returns 10

s = new Slice( 2, 10 );
// returns <Slice>

stop = s.stop;
// returns 10

Slice.prototype.step

Read-only property returning the slice index increment.

var s = new Slice( 10 );
// returns <Slice>

var step = s.step;
// returns null

s = new Slice( 2, 10 );
// returns <Slice>

step = s.step;
// returns null

s = new Slice( 2, 10, 1 );
// returns <Slice>

step = s.step;
// returns 1

Methods

Slice.prototype.toString()

Serializes a Slice as a string.

var s = new Slice( 10 );
// returns <Slice>

var str = s.toString();
// returns 'Slice(null,10,null)'

s = new Slice( 2, 10, 1 );
// returns <Slice>

str = s.toString();
// returns 'Slice(2,10,1)'

Slice.prototype.toJSON()

Serializes a Slice as a JSON object.

var s = new Slice( 10 );
// returns <Slice>

var o = s.toJSON();
// returns { 'type': 'Slice', 'data': [ null, 10, null ] }

s = new Slice( 2, 10, 1 );
// returns <Slice>

o = s.toJSON();
// returns { 'type': 'Slice', 'data': [ 2, 10, 1 ] }

JSON.stringify() implicitly calls this method when stringifying a Slice instance.

Notes

• Slice arguments may be either integers, null, or undefined, where a non-integer value indicates a slice parameter which should be determined based on the slice context (e.g., when used to index into an ndarray).
• Slice instances have no explicit functionality; however, they are used by ndarray and other packages for creating views into multi-dimensional data structures.

Examples

var Slice = require( '@stdlib/slice-ctor' );

var s = new Slice( 9, -10, -1 );
// returns <Slice>

var start = s.start;
console.log( 'Start: %d', start );
// => 'Start: 9'

var stop = s.stop;
console.log( 'Stop: %d', stop );
// => 'Stop: -10'

var step = s.step;
console.log( 'Step: %d', step );
// => 'Step: -1'

var str = s.toString();
console.log( str );
// => 'Slice(9,-10,-1)'

var o = s.toJSON();
console.log( JSON.stringify( o ) );
// => '{"type":"Slice","data":[9,-10,-1]}'

See Also

• @stdlib/ndarray-ctor: multidimensional array constructor.
• @stdlib/slice-multi: multi-slice constructor.

Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.

Community

License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.