All files / order/lib main.js

67.07% Statements 55/82
100% Branches 1/1
0% Functions 0/1
67.07% Lines 55/82

Press n or j to go to the next uncovered block, b, p or k for the previous block.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 831x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x 1x                                                       1x 1x 1x 1x 1x  
/**
* @license Apache-2.0
*
* Copyright (c) 2023 The Stdlib Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*    http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
 
'use strict';
 
// MODULES //
 
var isString = require( '@stdlib/assert/is-string' ).isPrimitive;
var strides2order = require( '@stdlib/ndarray/base/strides2order' );
 
 
// VARIABLES //
 
var ROW_MAJOR = 'row-major';
var COLUMN_MAJOR = 'column-major';
 
 
// MAIN //
 
/**
* Returns the layout order of a provided ndarray.
*
* @param {ndarrayLike} x - input ndarray
* @returns {(string|null)} layout order
*
* @example
* var zeros = require( '@stdlib/ndarray/zeros' );
*
* var x = zeros( [ 3, 3, 3 ], {
*     'order': 'row-major'
* });
*
* var out = order( x );
* // returns 'row-major'
*/
function order( x ) {
	var st;
	var o;

	o = x.order;
	if ( isString( o ) ) {
		return o;
	}
	// Try to infer the layout order from the strides array...
	st = x.strides;
	if ( typeof st !== 'object' || st === null ) {
		return ROW_MAJOR; // WARNING: default to row-major for ndarray-like objects lacking strides. This may or may not be accurate, and we're defaulting to row-major here based on the belief that row-major is more likely given that, e.g., JavaScript arrays are similar to C arrays (i.e., stored in row-major order).
	}
	o = strides2order( st );
	if ( o === 1 || o === 3 ) {
		return ROW_MAJOR; // for o == 3 (both row- and column-major; e.g., one-dimensional ndarrays), default to row-major
	}
	if ( o === 2 ) {
		return COLUMN_MAJOR;
	}
	// o === 0
	if ( x.shape.length === 0 ) {
		return ROW_MAJOR; // default to row-major for zero-dimensional ndarrays
	}
	// Case: mixed strides (e.g., [ 2, 3, 1 ] )
	return null;
}
 
 
// EXPORTS //
 
module.exports = order;