One of my single favorite Ruby features is: 

Object.methods

or my personal favorite version of this:

(obj.methods - Object.methods).sort

So if you have a string in Ruby you can say:

(“foo”.methods - Object.methods).sort

Here’s the equivalent of this in elixir:

Module.__info__(:functions)

So if you wanted to find out what Map can do you’d use:

Map.__info__(:functions)

or Enum:

Enum.__info__(:functions)

And you’ll get back a long list of functions. Here’s the result for Enum:

[all?: 1, all?: 2, any?: 1, any?: 2, at: 2, at: 3, chunk: 2, chunk: 3, chunk: 4,
 chunk_by: 2, concat: 1, concat: 2, count: 1, count: 2, dedup: 1, dedup_by: 2,
 drop: 2, drop_while: 2, each: 2, empty?: 1, fetch: 2, fetch!: 2, filter: 2,
 filter_map: 3, find: 2, find: 3, find_index: 2, find_value: 2, find_value: 3,
 flat_map: 2, flat_map_reduce: 3, group_by: 2, group_by: 3, intersperse: 2,
 into: 2, into: 3, join: 1, join: 2, map: 2, map_join: 2, map_join: 3,
 map_reduce: 3, max: 1, max_by: 2, member?: 2, min: 1, min_by: 2, min_max: 1,
 min_max_by: 2, partition: 2, ...]

You can also use the .module_info construct to get more information: 

Enum.module_info
[module: Enum,
 exports: [__info__: 1, join: 2, flat_map_reduce: 3, reduce_while: 3,
 sort_by: 3, sort_by: 2, filter: 2, uniq_by: 2, sort: 1, fetch!: 2, uniq: 2,
 join: 1, reverse_slice: 3, to_list: 1, group_by: 3, scan: 2, find: 3,
 concat: 2, sum: 1, at: 2, all?: 1, zip: 2, with_index: 2, split_while: 2,
 count: 1, sort: 2, empty?: 1, random: 1, dedup: 1, map_join: 2, find: 2,
 find_index: 2, reduce: 2, map_join: 3, count: 2, find_value: 2, min: 1,
 concat: 1, flat_map: 2, shuffle: 1, at: 3, uniq: 1, unzip: 1, min_by: 2,
 take_random: 2, take: 2, reverse: 2, find_value: 3, ...],
 attributes: [vsn: [332892874748555839594542519652485069262]],
 compile: [options: [:debug_info], version: '6.0.2',
 time: {2016, 2, 21, 21, 48, 31},
 source: '/private/tmp/elixir20160221-76790-1cjto8i/elixir-1.2.3/lib/elixir/lib/enum.ex'],
 native: false,
 md5: <<250, 112, 213, 232, 64, 152, 188, 238, 148, 116, 149, 143, 81, 114, 121, 206>>]

 Here’s a helpful Stack Overflow link on the subject.