fixed issues & implementation of predicate functions at all places

Author: bad-in-coding

lib/node_modules/@stdlib/array/base/count-if/README.md

@@ -40,19 +40,46 @@ limitations under the License.
 var countIf = require( '@stdlib/array/base/count-if' );
 ```
 
-#### countIf( x, predicate[, thisArg] )
+#### countIf( x, predicate\[, thisArg] )
 
 Counts the number of elements in an array that satisfy the provided testing function.
 
 ```javascript
 var x = [ 0, 1, 0, 1, 2 ];
 
-var predicate = function isEven( value ){ return ( value % 2 === 0 ) };
+function predicate( val ) { 
+    return ( val % 2 === 0; ) 
+};
 
 var out = countIf( x, predicate );
 // returns 3
 ```
 
+If a `predicate` function returns a truthy value, the function counts that value.
+
+The `predicate` function is provided three arguments:
+
+-   **value**: current array element.
+-   **index**: current array element index.
+-   **arr**: input array.
+
+To set the `predicate` function execution context, provide a `thisArg`.
+
+```javascript
+function predicate( value ) {
+    return ( value > this.target );
+}
+
+var x = [ 1, 2, 3, 4 ];
+
+var context = {
+    target: 3
+};
+
+var out = countIf( x, predicate, context );
+// returns 1
+```
+
 </section>
 
 <!-- /.usage -->
@@ -82,8 +109,9 @@ var x = bernoulli( 100, 0.5, {
 });
 console.log( x );
 
-var predicate = function ( val ) { return val === 1 }
-
+function predicate( val ) { 
+    return val === 1; 
+}
 var n = countIf( x, predicate );
 console.log( n );
 ```

lib/node_modules/@stdlib/array/base/count-if/docs/repl.txt

@@ -11,7 +11,7 @@
         Testing function.
 
     thisArg: any (optional)
-        Input function's context.
+        Execution context.
 
     Returns
     -------

lib/node_modules/@stdlib/array/base/count-if/docs/types/index.d.ts

@@ -32,8 +32,10 @@ import { Collection } from '@stdlib/types/array';
 *
 * @example
 * var x = [ 0, 1, 0, 1 ];
-* var predicate = function( v, t ){ return v > t; }
-* var n = indexed( x, predicate, 0 );
+* var predicate = function( v ) { 
+*     return v > this; 
+* }
+* var n = indexed( x, predicate );
 * // returns 2
 */
 declare function countIf( x: Collection, predicate: ( ...args: any[] ) => boolean, thisArg?: any ): number;

lib/node_modules/@stdlib/array/base/count-if/examples/index.js

@@ -26,9 +26,12 @@ var x = bernoulli( 100, 0.5, {
 });
 console.log( x );
 
-var big = 10;
+var threshold = 0;
 
-var predicate = function isBig( val, big ) { return (val > big) }
+function predicate( val ) { 
+	return (val > this) 
+}
 
-var n = countIf( x, predicate, big );
+var n = countIf( x, predicate, threshold );
 console.log( n );
+

lib/node_modules/@stdlib/array/base/count-if/lib/index.js

@@ -19,7 +19,7 @@
 'use strict';
 
 /**
-* Counts the number of elements in an array that satisfy the provided testing function.
+* Count the number of elements in an array that satisfy the provided testing function.
 *
 * @module @stdlib/array/base/count-if
 *
@@ -28,7 +28,9 @@
 *
 * var x = [ 0, 1, 0, 1, 2 ];
 *
-* var predicate = function isEven( value ){ return ( value % 2 === 0 ) };
+* function predicate( value ) { 
+*     return ( value % 2 === 0 ) 
+* };
 *
 * var n = countIf( x, predicate );
 * // returns 3

lib/node_modules/@stdlib/array/base/count-if/lib/main.js

@@ -39,8 +39,10 @@ var reinterpret = require( '@stdlib/strided/base/reinterpret-complex' );
 *
 * @example
 * var x = [ 0, 1, 0, 1 ];
-* var predicate = function( v, thisArg ){ return v > thisArg; }
-* var n = indexed( x, predicate, 0 );
+* function predicate( v ) { 
+*     return v > 0;
+* }
+* var n = indexed( x, predicate );
 * // returns 2
 */
 function indexed( x, predicate, thisArg ) {
@@ -49,7 +51,7 @@ function indexed( x, predicate, thisArg ) {
 
 	n = 0;
 	for ( i = 0; i < x.length; i++ ) {
-		if ( predicate( x[ i ], thisArg ) ) {
+		if ( predicate.call( thisArg, x[ i ], i, x ) ) {
 			n += 1;
 		}
 	}
@@ -69,8 +71,10 @@ function indexed( x, predicate, thisArg ) {
 * var toAccessorArray = require( '@stdlib/array/base/to-accessor-array' );
 *
 * var x = toAccessorArray( [ 0, 1, 0, 1 ] );
-* var predicate = function( v, thisArg ){ return v > thisArg; }
-* var n = accessors( x, predicate, 0 );
+* function predicate( v ) {
+*	return v > 0; 
+* }
+* var n = accessors( x, predicate );
 * // returns 2
 */
 function accessors( x, predicate, thisArg ) {
@@ -82,7 +86,7 @@ function accessors( x, predicate, thisArg ) {
 
 	n = 0;
 	for ( i = 0; i < x.length; i++ ) {
-		if ( predicate( get( x, i ), thisArg ) ) {
+		if ( predicate.call( thisArg, get( x, i ), i, x ) ) {
 			n += 1;
 		}
 	}
@@ -96,14 +100,16 @@ function accessors( x, predicate, thisArg ) {
 * @param {Collection} x - input array
 * @param {(...args: any[]) => boolean} predicate - testing array
 * @param {*} [thisArg] - function context
-* @returns {NonNegativeInteger} number of values for which the provided function evalutes to true
+* @returns {NonNegativeInteger} number of values for which the provided function evaluates to true
 *
 * @example
 * var Complex128Array = require( '@stdlib/array/complex128' );
 *
 * var x = new Complex128Array( [ 1.0, 2.0, 0.0, 0.0, 3.0, 4.0, 0.0, 0.0 ] );
-* var predicate = function( v, thisArg ){ return v > thisArg; }
-* var n = complex( x );
+* function predicate( v ) {
+*	return v > 0; 
+* }
+* var n = complex( x, predicate );
 * // returns 2
 */
 function complex( x, predicate, thisArg ) {
@@ -115,7 +121,7 @@ function complex( x, predicate, thisArg ) {
 
 	n = 0;
 	for ( i = 0; i < view.length; i += 2 ) {
-		if ( predicate( view[ i ], thisArg ) || predicate( view[ i+1 ], thisArg ) ) {
+		if ( predicate.call( thisArg, view[ i ], i, view ) || predicate.call( thisArg, view[ i+1 ], i+1, view ) ) {
 			n += 1;
 		}
 	}
@@ -135,8 +141,10 @@ function complex( x, predicate, thisArg ) {
 *
 * @example
 * var x = [ 0, 1, 0, 1, 1 ];
-* var predicate = function( v, thisArg ){ return v > thisArg; }
-* var n = countTruthy( x );
+* function predicate( v ) {
+*	return v > 0; 
+* }
+* var n = countIf( x, predicate );
 * // returns 3
 */
 function countIf( x, predicate, thisArg ) {

lib/node_modules/@stdlib/array/base/count-if/package.json

@@ -1,7 +1,7 @@
 {
   "name": "@stdlib/array/base/count-if",
   "version": "0.0.0",
-  "description": "Counts the number of elements in an array that satisfy the provided testing function.",
+  "description": "Count the number of elements in an array that satisfy the provided testing function.",
   "license": "Apache-2.0",
   "author": {
     "name": "The Stdlib Authors",

lib/node_modules/@stdlib/array/base/count-if/test/test.js

@@ -39,12 +39,13 @@ tape( 'the function counts the number of truthy values based on a testing functi
     var expected;
     var actual;
     var x;
+    var thisArg = 2;
 
     x = [ 0, 1, 0, 1, 2 ];
     expected = 3;
-    actual = countIf( x, function( v, thisArg ) {
-        return ( v % thisArg === 0 );
-    }, 2 );
+    actual = countIf( x, function( v ) {
+        return ( v % this === 0 );
+    }, thisArg );
 
     t.strictEqual( actual, expected, 'returns expected value' );
     t.end();
@@ -69,12 +70,13 @@ tape( 'the function counts the number of truthy values based on a testing functi
     var expected;
     var actual;
     var x;
+    var thisArg = 1;
 
     x = new Int32Array([ 0, 1, 0, 1, 2 ]);
     expected = 1;
-    actual = countIf( x, function( v, thisArg ) {
-        return v > thisArg;
-    }, 1 );
+    actual = countIf( x, function( v ) {
+        return v > this;
+    }, thisArg );
 
     t.strictEqual( actual, expected, 'returns expected value' );
     t.end();
@@ -165,13 +167,15 @@ tape( 'the function supports providing a custom execution context', function tes
     var expected;
     var actual;
     var x;
-    var threshold = 2;
+    var context = {
+        threshold : 2
+    };
 
     x = [ 1, 2, 3, 4, 5 ];
     expected = 3; // Only values greater than 2
-    actual = countIf( x, function( v, thisArg ) {
-        return v > thisArg;
-    }, threshold );
+    actual = countIf( x, function( v ) {
+        return v > this.threshold;
+    }, context );
 
     t.strictEqual( actual, expected, 'returns expected value' );
 
@@ -183,7 +187,9 @@ tape( 'the function counts the number of objects with a custom predicate functio
     var expected;
     var actual;
     var x;
-    var target = 20;
+    var thisArg = { 
+        target : 20
+    };
 
     x = [
         { name: 'John', value: 10 },
@@ -192,11 +198,21 @@ tape( 'the function counts the number of objects with a custom predicate functio
     ];
     // Count the number of objects where the value property matches the target
     expected = 1; // One object have its value property equal to 20
-    actual = countIf( x, function( v, thisArg ) {
-        return v.value === thisArg;
-    }, target );
+    actual = countIf( x, function( v ) {
+        return v.value === this.target;
+    }, thisArg );
 
     t.strictEqual( actual, expected, 'returns expected value' );
 
     t.end();
 });
+
+tape( 'the function returns zero if provided an array with no truthy values (false, null, undefined are treated as non truthy values)', function test( t ) {
+    var expected = 0;
+    var x = [ false, 0, '', null, undefined ];
+    var actual = countIf( x, function( v ) {
+        return v; // Returns truthy values
+    });
+    t.strictEqual( actual, expected, 'returns expected value' );
+    t.end();
+});