Dig

This repo hosts a few experimental updates to Ruby's dig method.

Ruby already has a dig method on Hash and Array classes, but it has a couple limitations:

1. It works very much like fetch, but doesn't accept a default value like fetch does.
2. There's no easy way to use it to update a deeply nested structure.
3. If you dig into something that's not a Hash or Array, you'll get an exception.
4. There's no documentation telling you that you can use it for Hashes nested inside Arrays, and vice-versa.

Usage

x=[1,{a: {b: 2}}]# These are existing behaviors.x.dig(1,:a,:b)# => 2x.dig(1,:a,:c)# => nilx.dig(1,:a,:b,:c)# => TypeError: Integer does not have #dig method# These are behaviors that we're adding.x.dig(1,:a,:c){3}# => 3x.dig(1,:a,:c){ |index_or_key| "Can't find '#{index_or_key}'"}# => "Can't find 'c'"x.dig(1,:a,:b,:c)# => nil (NOTE: This changes existing behavior, so might not be worth doing.)x.dig(1,:a,:b,:c){nil}# => nilx.dig!(1,:a){ |a| a[:b]=4}# => [1, {a: {b: 4}}]x.dig!(1,:a){ |a| a.delete(:b)}# => [1, {a: {}}]

Notes

• dig! is roughly equivalent to Elixir's Kernel.update_in
• For something similar, but more extensive, take a look at scopes in xf