Enum fusion?

[bjorng]

@hst337

This particular optimization is useless, but flattening of nested cases can reduce amount of code, reduce amount of clauses and help generate more efficient switch instructions

You mean it’s useless because the Erlang compiler will generate the same BEAM code for both examples?

I would be interested in (real-world) examples where the Erlang compiler is unable to do that optimization. If we could improve the Erlang compiler to generate better code for nested cases it would benefit the entire BEAM community.

@josevalim

In this case, once maybe expressions are fully integrated to Erlang/OTP, I am hoping we can compile to something more efficient.

In Erlang/OTP 26, it sufficient to enable the maybe feature in the compiler. There is no longer any need to enable it in the runtime system too for it to work. We realized that we had to do that so that we could use maybe in OTP code.