bifurcateOwn

Usage

var bifurcateOwn = require( '@stdlib/utils/bifurcate-own' );

bifurcateOwn( obj, [options,] predicate )

Splits an object's own property values into two groups according to a predicate function, which specifies which group a value in the input object belongs to. If a predicate function returns a truthy value, a value belongs to the first group; otherwise, a value belongs to the second group.

function predicate( v ) {
    return v[ 0 ] === 'b';
}
var obj = {
    'a': 'beep',
    'b': 'boop',
    'c': 'foo',
    'd': 'bar'
};

var out = bifurcateOwn( obj, predicate );
// e.g., returns [ [ 'beep', 'boop', 'bar' ], [ 'foo' ] ]

A predicate function is provided two arguments:

• value: object value
• key: object index

function predicate( v, k ) {
    console.log( '%s: %s', k, v );
    return v[ 0 ] === 'b';
}
var obj = {
    'a': 'beep',
    'b': 'boop',
    'c': 'foo',
    'd': 'bar'
};

var out = bifurcateOwn( obj, predicate );
// e.g., returns [ [ 'beep', 'boop', 'bar' ], [ 'foo' ] ]

The function accepts the following options:

• returns: specifies the output format. If the option equals 'values', the function outputs values. If the option equals 'keys', the function outputs keys. If the option equals '*', the function outputs both keys and values. Default: 'values'.
• thisArg: execution context.

By default, the function returns object values. To return object keys, set the returns option to 'keys'.

function predicate( v ) {
    return v[ 0 ] === 'b';
}
var obj = {
    'a': 'beep',
    'b': 'boop',
    'c': 'foo',
    'd': 'bar'
};

var opts = {
    'returns': 'keys'
};
var out = bifurcateOwn( obj, opts, predicate );
// e.g., returns [ [ 'a', 'b', 'd' ], [ 'c' ] ]

To return key-value pairs, set the returns option to '*'.

function predicate( v ) {
    return v[ 0 ] === 'b';
}
var obj = {
    'a': 'beep',
    'b': 'boop',
    'c': 'foo',
    'd': 'bar'
};

var opts = {
    'returns': '*'
};
var out = bifurcateOwn( obj, opts, predicate );
// e.g., returns [ [ [ 'a', 'beep' ], [ 'b', 'boop ], [ 'd', 'bar' ] ], [ [ 'c', 'foo' ] ] ]

To set the predicate execution context, provide a thisArg.

function predicate( v ) {
    this.count += 1;
    return v[ 0 ] === 'b';
}
var context = {
    'count': 0
};
var opts = {
    'thisArg': context
};
var obj = {
    'a': 'beep',
    'b': 'boop',
    'c': 'foo',
    'd': 'bar'
};
var out = bifurcateOwn( obj, opts, predicate );
// e.g., returns [ [ 'beep', 'boop', 'bar' ], [ 'foo' ] ]

console.log( context.count );
// => 4