Actions
Feature #18008
closed`keyword_init?` method for Struct
Status:
Closed
Assignee:
-
Target version:
-
Description
I'd like to know whether my struct was initialized with keyword_init: true
or not.
This information is useful when writing a deserializer (attached an example below).
S1 = Struct.new(:a, :b, keyword_init: true)
S2 = Struct.new(:a, :b)
# Specialized for Struct
def serialize(d)
d.to_h.merge(__class_name: d.class.name)
end
def deserialize(h)
klass = Object.const_get(h.delete(:__class_name))
if keyword_init?(klass)
# If the class is created with keyword_init: true, the parameter should be passed as keywords
klass.new(**h)
else
# Otherwise, each values are passed in the order of members.
klass.new(*klass.members.map { |sym| h[sym] })
end
end
def keyword_init?(klass)
# I don't want to do this...
# klass.keyword_init? looks cool.
klass.inspect.end_with?('(keyword_init: true)')
end
s1 = S1.new(a: 1, b: 2)
p s1
p s1_ = deserialize(serialize(s1))
p s1 == s1_
s2 = S2.new(1, 2)
p s2
p s2_ = deserialize(serialize(s2))
p s2 == s2_
Updated by k0kubun (Takashi Kokubun) over 3 years ago
+1. While we aim to obviate keyword_init
in [Feature #16806], unless we also intend to deprecate the option (for now we don't), we'd need to have the check to correctly write a deserializer of Structs.
Updated by matz (Yukihiro Matsumoto) about 3 years ago
Accepted.
Matz.
Updated by naruse (Yui NARUSE) about 3 years ago
hkdnet's patch is https://github.com/ruby/ruby/pull/4609
Updated by hkdnet (Ko Sato) about 3 years ago
- Status changed from Open to Closed
Applied in changeset git|1a637544166eca6b917fb6f32baeb771f4914b7a.
struct.c: Add keyword_init? singleton method for StructClass (#4609)
Fixes [Feature #18008]
Actions
Like0
Like0Like0Like0Like0