partialapplication.js

// Library method --------------------------------------------------------------

var pluckWith = function(k, a) {
    return function(v) {
        var res = [];
        for (var i = 0; i < a.length; i++)
            if (a[i].hasOwnProperty(k) && a[i][k] === v)
                res.push(a[i]);
        return res;
    };
};

// Use case --------------------------------------------------------------------

// lightweight database ;) ;)
var db = [
    {name: 'dumbo', age: 12},
    {name: 'dumbo', age: 12},
    {name: 'jasper', age: 12},
    {name: 'carlos', age: 24}];

// search methods
var getByName = pluckWith('name', db),
    getByAge = pluckWith('age', db);

// do the searching whenever you need!
var peopleNamedCarlos = getByName('carlos'),
    peopeWhoAre12YearsOld = getByAge(12);

console.log(peopleNamedCarlos);
console.log(peopeWhoAre12YearsOld);