https://github.com/jeremywrnr/deepmap
:milky_way: deep ruby hash/array map
https://github.com/jeremywrnr/deepmap
hash map ruby rubygems
Last synced: about 1 year ago
JSON representation
:milky_way: deep ruby hash/array map
- Host: GitHub
- URL: https://github.com/jeremywrnr/deepmap
- Owner: jeremywrnr
- Created: 2016-04-19T18:46:53.000Z (about 10 years ago)
- Default Branch: main
- Last Pushed: 2023-03-10T01:05:33.000Z (about 3 years ago)
- Last Synced: 2025-03-23T23:43:13.235Z (about 1 year ago)
- Topics: hash, map, ruby, rubygems
- Language: Ruby
- Homepage: https://rubygems.org/gems/deepmap
- Size: 13.7 KB
- Stars: 7
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: readme.md
Awesome Lists containing this project
README
# deepmap
[](https://badge.fury.io/rb/deepmap)
[](http://jeremywrnr.com/mit-license)
## setup
[sudo] gem install deepmap
## about
Ruby gem that adds three methods to the Hash and Array classes. Overview:
* `#deep_map` - apply block to each key and value in object
* `#key_map` - apply block to each key in object
* `#val_map` - apply block to each value in object
These may be useful when you want to apply a function to each value (or key or
pair) of a complex nested object (such as the result of parsing a YAML or JSON
file), which can have hashes or arrays as subfields. The function currently
needs to be passed in as a block (see usage).
## usage
```ruby
irb(main):001:0> require 'deepmap'
=> true
irb(main):002:0> test = { 1 => 4, 2 => [5, 6], 3 => { 4 => [1, 2, { 5 => 10 }] } }
=> {1=>4, 2=>[5, 6], 3=>{4=>[1, 2, {5=>10}]}}
irb(main):003:0> test.deep_map {|i| i.to_i * 2 }
=> {2=>8, 4=>[10, 12], 6=>{8=>[2, 4, {10=>20}]}}
irb(main):004:0> test.key_map {|i| i.to_i * 2 }
=> {2=>4, 4=>[5, 6], 6=>{8=>[1, 2, {10=>10}]}}
irb(main):005:0> test.val_map {|i| i.to_i * 2 }
=> {1=>8, 2=>[10, 12], 3=>{4=>[2, 4, {5=>20}]}}
```
Once you `require 'deepmap'`, you can call any of the three provided functions
on any (existing or new!) hash or array, as demonstrated above. You can also
use the (`&:method`) shortcut to call a method on each object concisely:
```ruby
irb(main):002:0> test = { 'a' => 'b', 'c' => ['d', 'e'], 'f' => { 'g' => ['h', 'i', { 'j' => 'k' }] } }
=> {"a"=>"b", "c"=>["d", "e"], "f"=>{"g"=>["h", "i", {"j"=>"k"}]}}
irb(main):003:0> test.deep_map(&:upcase)
=> {"A"=>"B", "C"=>["D", "E"], "F"=>{"G"=>["H", "I", {"J"=>"K"}]}}
irb(main):004:0> test.key_map(&:upcase)
=> {"A"=>"b", "C"=>["d", "e"], "F"=>{"G"=>["h", "i", {"J"=>"k"}]}}
irb(main):005:0> test.val_map(&:upcase)
=> {"a"=>"B", "c"=>["D", "E"], "f"=>{"g"=>["H", "I", {"j"=>"K"}]}}
```
## development / testing
First, clone this repo:
git clone https://github.com/jeremywrnr/deepmap.git
To build from source, first install the project dependencies. This project
uses `bundler`, the standard ruby gem management system. If you don't have it,
try running `gem install bundler`. Once that is done:
bundle install
Now, we should be able to build the gem locally. This will build the local
deepmap gem and link it in your path, so you can playing around with `deepmap`.
bundle exec rake build
This uses `rspec` and `rake` to run a suite of unit tests. To run the suite:
bundle exec rake
## todo
* collison checking/warning/confirmation workflow
* support key-val iteration in mapping over vals/keys. This would allow support
for mapping conditionally based on a key/value, even if you are iterating
over all values/keys (`key_map {|k, v| k > 0 ? k : v }`).