Add Hash#compact and Hash#compact! #3821

makenowjust · 2017-01-02T04:54:21Z

Ruby 2.4 has Hash#compact and Hash#compact!. This pull request introduces them into Crystal.

Hash#compact makes a new Hash without all nil values:

h1 = {"hello" => "world", "foo" => nil}
h1.class # => Hash(String, String | Nil)
h2 = h1.compact
h2       # => {"hello" => "world"}
h2.class # => Hash(String, String)

And, Hash#compact! removes all nil values from self, and returns self or nil if it were made no changes like Hash#reject!:

h1 = {"hello" => "world", "foo" => nil}
h1.compact! # => {"hello" => "world"}
h1          # => {"hello" => "world"}
h1.class    # => Hash(String, String | Nil)
h1.compact! # => nil

Their behaviors are same as Ruby.

Ruby 2.4 has `Hash#compact` and `Hash#compact!`. This commit introduces them to Crystal.

asterite · 2017-01-04T14:25:14Z

I don't think compact and compact! are very useful in Crystal, because nil as a key/value in array/hashes is not very common, but for the few cases where one uses that (maybe as a result of a map or other operations) it can be useful. So let's merge this :-)

Thank you!

Add Hash#compact and Hash#compact!

51e3e99

Ruby 2.4 has `Hash#compact` and `Hash#compact!`. This commit introduces them to Crystal.

asterite merged commit d4ef40c into crystal-lang:master Jan 4, 2017

asterite added kind:feature topic:stdlib labels Jan 4, 2017

asterite added this to the 0.20.4 milestone Jan 4, 2017

makenowjust deleted the feature/hash/compact branch January 4, 2017 14:28

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Add Hash#compact and Hash#compact! #3821

Add Hash#compact and Hash#compact! #3821

makenowjust commented Jan 2, 2017 •

edited

asterite commented Jan 4, 2017

Add Hash#compact and Hash#compact! #3821

Add Hash#compact and Hash#compact! #3821

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makenowjust commented Jan 2, 2017 • edited

asterite commented Jan 4, 2017

makenowjust commented Jan 2, 2017 •

edited