Ruby accepts a[&b]=c but Prism rejects it

[tompng]

Prism rejects these codes. Ruby and YARP 0.12.0 accepts it.

a[&b] = c
a[&b] += c
a[&b] ||= c
a[&b] &&= c

I'm not sure if it's related to this issue or not, Prism::CallNode have method block but Prism::CallOperatorNode Prism::CallAndWriteNode Prism::CallOrWriteNode does not have it.

[eregon]

Maybe it's a case that CRuby should forbid?
I think this syntax might not be intentionally supported.
Could you open an issue at https://bugs.ruby-lang.org/ to find out?

It does seem to "work" in CRuby to be fair:

$ ruby -e 'a=Object.new; c=42; b=->{}; def a.[]=(*a,&b); p [a,b]; end; a[&b] = c'
[[42], #<Proc:0x00007fc5e22bd1a8 -e:1 (lambda)>]

[tompng]

Opened https://bugs.ruby-lang.org/issues/19918

[kddnewton]

Thanks @tompng - regardless of whether it's good or not, we need to support it to be compatible. Fortunately I don't think this will be too bad.