different behavior each_with_index.inject

[matsumotory]

Hi, @matz

each_with_index.inject of mruby is a different behavior with CRuby.

• mruby

> ["a", "b", "c"].each_with_index.inject("d") { |a, (b, c)| p a, b, c }
"d"
["a", 0]
nil
"d"
["b", 1]
nil
"d"
["c", 2]
nil
 => "d"

• CRuby

irb(main):006:0> ["a", "b", "c"].each_with_index.inject("d") { |a, (b, c)| p a, b, c }
"d"
"a"
0
["d", "a", 0]
"b"
1
[["d", "a", 0], "b", 1]
"c"
2
=> [[["d", "a", 0], "b", 1], "c", 2]

[matz]

mruby does not support destructuring in assignment or block parameters yet. #2841

[matsumotory]

Ah…sorry, Thank you for your pointer!

[matz]

Sorry for leaving destructuring unimplemented.

[zzak]

@matz Is there a reason it's not implemented? Should we put it on the roadmap, or is there another limitation I'm missing?

[matz]

It's difficult (but not impossible) to implement destructuring without adding new instruction (for the sake for compatibility).