Iterate over Ruby FFI Struct layout
I am us开发者_Go百科ing the really awesome ruby ffi library to access functions in a c library in ruby.
Is there a way to iterate over the layout of a Ruby FFI::Struct?
example FFI::Struct:
class Example < FFI::Struct
layout :name, string,
:desc, :string,
:type, :int,
:value, :string
end
this doesn't seem to work but something like the below pseudo code:
example_struct.each_key do |key|
puts key
end
Looking at the source for struct.rb, I found that you can call Struct::members
to get an array of the symbols you've defined as "keys".
From there, you've also got Struct::values
for the values of each member, Struct::offsets
for the offsets of each member, and a few other methods.
Surely a bit more expensive than iterating through the Struct's members, but you can also convert it to a hash with to_h
.
Foo = Struct.new(:a, :b, :c)
=> Foo
baz = Foo.new(1,2,3)
=> #<struct Foo a=1, b=2, c=3>
baz.to_h
=> {:a=>1, :b=>2, :c=>3}
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