Schwartzian transform for js
The goal of this project is to provide a library for sorting arrays in a
similar fashion to Ruby's Array#sort_by.
In addition to standard sorting, schwartz uses a special compareArrays method
to compare two arrays similar to Ruby's <=> operator.
Schwartz is very simple to use. Instead of providing a sorting function, a transform function is provided which will provide the value to compare for each item in the array.
/* sort by user_id */
//standard way
users.sort(function (a, b) {
var aValue = a.user_id;
var bValue = b.user_id;
return aValue < bVlaue ? -1
: aValue > bValue ? 1
: 0;
});
//call schwartz.useDaSchwartz() to bind .schwartz to the Array prototype.
schwartz.useDaSchwartz();
var sortedUsers = users.schwartz(function (user) {
return user.user_id;
});To sort along multiple criteria, we return an array:
//sort by first name, last name, created_at
var sortedUsers = users.schwartz(function (user) {
return [user.first_name, user.last_name, user.created_at];
});
//if we want sort null values last, we should place an impossibly high value as the default
var sortedUsers = users.schwartz(function (user) {
return [user.first_name || 'ZZZZZZ', user.last_name || 'ZZZZZZ', user.created_at || new Date(9999,1,1)];
});ISC