From: eregontp@...
Date: 2016-12-15T10:41:15+00:00
Subject: [ruby-core:78658] [Ruby trunk Feature#12719] `Struct#merge` for	partial updates

Issue #12719 has been updated by Benoit Daloze.


Scala has "copy" for this purpose: some_case_class_object.copy(field: new_value)

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Feature #12719: `Struct#merge` for partial updates
https://bugs.ruby-lang.org/issues/12719#change-62040

* Author: Matthew Mongeau
* Status: Feedback
* Priority: Normal
* Assignee: 
* Target version: 
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Other languages have operators for performing partial updates on maps. I feel like Struct could be more useful if it provided an easy way of performing partial (or full) updates.

After the change you can do the following:

~~~ ruby
Point = Struct.new(:x, :y)

p = Point.new(1, 2)
p2 = p.merge(y: 4)
p3 = p2.merge(x: 10)

p.inspect     # => #<struct Point x=1, y=2>
p2.inspect   # => #<struct Point x=1, y=4>
p3.inspect   # => #<struct Point x=10, y=4>

p.merge!("x" => 9)

p.inspect    # => #<struct Point x=9, y=2>
~~~

---Files--------------------------------
struct_merge.patch (2.93 KB)


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