sliceLength

Compute the number of elements in a normalized slice.

Installation

npm install @stdlib/slice-base-length

Usage

var sliceLength = require( '@stdlib/slice-base-length' );

sliceLength( slice )

Returns the number of elements in a normalized slice.

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

var s = normalizeSlice( new Slice( -3, null, -1 ), 10, false );
// returns <Slice>

var len = sliceLength( s );
// returns 8

Examples

var Slice = require( '@stdlib/slice-ctor' );
var normalizeSlice = require( '@stdlib/slice-base-normalize-slice' );
var incrspace = require( '@stdlib/array-base-incrspace' );
var sliceLength = require( '@stdlib/slice-base-length' );

var s1 = new Slice( 2, null, -1 );
var s2 = normalizeSlice( s1, 10, false );
var v = sliceLength( s2 );
console.log( '%s => %s => %d', s1.toString(), s2.toString(), v );
console.log( '[ %s ]', incrspace( s2.start, s2.stop || -1, s2.step ).join( ', ' ) );
// => '[ 2, 1, 0 ]'

s1 = new Slice( null, null, -3 );
s2 = normalizeSlice( s1, 10, false );
v = sliceLength( s2 );
console.log( '%s => %s => %d', s1.toString(), s2.toString(), v );
console.log( '[ %s ]', incrspace( s2.start, s2.stop || -1, s2.step ).join( ', ' ) );
// => '[ 9, 6, 3, 0 ]'

s1 = new Slice( null, 8, 3 );
s2 = normalizeSlice( s1, 10, false );
v = sliceLength( s2 );
console.log( '%s => %s => %d', s1.toString(), s2.toString(), v );
console.log( '[ %s ]', incrspace( s2.start, s2.stop || -1, s2.step ).join( ', ' ) );
// => '[ 0, 3, 6 ]'

s1 = new Slice( null, 8, null );
s2 = normalizeSlice( s1, 10, false );
v = sliceLength( s2 );
console.log( '%s => %s => %d', s1.toString(), s2.toString(), v );
console.log( '[ %s ]', incrspace( s2.start, s2.stop || -1, s2.step ).join( ', ' ) );
// => '[ 0, 1, 2, 3, 4, 5, 6, 7 ]'

s1 = new Slice( -4, null, -2 );
s2 = normalizeSlice( s1, 10, false );
v = sliceLength( s2 );
console.log( '%s => %s => %d', s1.toString(), s2.toString(), v );
console.log( '[ %s ]', incrspace( s2.start, s2.stop || -1, s2.step ).join( ', ' ) );
// => '[ 6, 4, 2, 0 ]'

s1 = new Slice( null, 8, 3 );
s2 = normalizeSlice( s1, 10, false );
v = sliceLength( s2 );
console.log( '%s => %s => %d', s1.toString(), s2.toString(), v );
console.log( '[ %s ]', incrspace( s2.start, s2.stop || -1, s2.step ).join( ', ' ) );
// => '[ 0, 3, 6 ]'

s1 = new Slice( 8, 2, -2 );
s2 = normalizeSlice( s1, 10, false );
v = sliceLength( s2 );
console.log( '%s => %s => %d', s1.toString(), s2.toString(), v );
console.log( '[ %s ]', incrspace( s2.start, s2.stop || -1, s2.step ).join( ', ' ) );
// => '[ 8, 6, 4 ]'

s1 = new Slice( 3, 8, 2 );
s2 = normalizeSlice( s1, 10, false );
v = sliceLength( s2 );
console.log( '%s => %s => %d', s1.toString(), s2.toString(), v );
console.log( '[ %s ]', incrspace( s2.start, s2.stop || -1, s2.step ).join( ', ' ) );
// => '[ 3, 5, 7 ]'

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.