time-to-botec

Benchmark sampling in different programming languages
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main.js (2540B)

      1 /**
      2 * @license Apache-2.0
      3 *
      4 * Copyright (c) 2018 The Stdlib Authors.
      5 *
      6 * Licensed under the Apache License, Version 2.0 (the "License");
      7 * you may not use this file except in compliance with the License.
      8 * You may obtain a copy of the License at
      9 *
     10 *    http://www.apache.org/licenses/LICENSE-2.0
     11 *
     12 * Unless required by applicable law or agreed to in writing, software
     13 * distributed under the License is distributed on an "AS IS" BASIS,
     14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     15 * See the License for the specific language governing permissions and
     16 * limitations under the License.
     17 */
     18 
     19 'use strict';
     20 
     21 // MODULES //
     22 
     23 var objectKeys = require( '@stdlib/utils/keys' );
     24 var hasOwnProp = require( '@stdlib/assert/has-own-property' );
     25 var SAFE_CASTS = require( './safe_casts.json' );
     26 
     27 
     28 // VARIABLES //
     29 
     30 var TABLE;
     31 
     32 
     33 // FUNCTIONS //
     34 
     35 /**
     36 * Generates a full table of safe casts for each array data type.
     37 *
     38 * @private
     39 * @returns {Object} table
     40 */
     41 function generateFullTable() {
     42 	var dtypes;
     43 	var ntypes;
     44 	var out;
     45 	var tmp;
     46 	var dt1;
     47 	var dt2;
     48 	var o;
     49 	var j;
     50 	var i;
     51 
     52 	out = {};
     53 	dtypes = objectKeys( SAFE_CASTS );
     54 	ntypes = dtypes.length;
     55 	for ( i = 0; i < ntypes; i++ ) {
     56 		dt1 = dtypes[ i ];
     57 		o = SAFE_CASTS[ dt1 ];
     58 		tmp = {};
     59 		for ( j = 0; j < ntypes; j++ ) {
     60 			dt2 = dtypes[ j ];
     61 			tmp[ dt2 ] = o[ dt2 ];
     62 		}
     63 		out[ dt1 ] = tmp;
     64 	}
     65 	return out;
     66 }
     67 
     68 /**
     69 * Generates a table of safe casts for each array data type.
     70 *
     71 * @private
     72 * @returns {Object} table
     73 */
     74 function generateTable() {
     75 	var dtypes;
     76 	var ntypes;
     77 	var out;
     78 	var tmp;
     79 	var dt1;
     80 	var dt2;
     81 	var o;
     82 	var j;
     83 	var i;
     84 
     85 	out = {};
     86 	dtypes = objectKeys( SAFE_CASTS );
     87 	ntypes = dtypes.length;
     88 	for ( i = 0; i < ntypes; i++ ) {
     89 		dt1 = dtypes[ i ];
     90 		o = SAFE_CASTS[ dt1 ];
     91 		tmp = [];
     92 		for ( j = 0; j < ntypes; j++ ) {
     93 			dt2 = dtypes[ j ];
     94 			if ( o[ dt2 ] === 1 ) {
     95 				tmp.push( dt2 );
     96 			}
     97 		}
     98 		out[ dt1 ] = tmp;
     99 	}
    100 	return out;
    101 }
    102 
    103 
    104 // MAIN //
    105 
    106 /**
    107 * Returns a list of array data types to which a provided array data type can be safely cast.
    108 *
    109 * @param {string} [dtype] - array data type
    110 * @returns {(Object|StringArray|null)} list of array data types or null
    111 *
    112 * @example
    113 * var list = safeCasts( 'float32' );
    114 * // returns [...]
    115 */
    116 function safeCasts( dtype ) {
    117 	if ( arguments.length === 0 ) {
    118 		return generateFullTable();
    119 	}
    120 	if ( TABLE === void 0 ) {
    121 		// Lazily generate table...
    122 		TABLE = generateTable();
    123 	}
    124 	if ( hasOwnProp( TABLE, dtype ) ) {
    125 		return TABLE[ dtype ].slice();
    126 	}
    127 	return null;
    128 }
    129 
    130 
    131 // EXPORTS //
    132 
    133 module.exports = safeCasts;