parse error with unary operators +-*/%

[lateau]

our parser does not allows something weird but ruby does:

------1

•     -1
  

actually, ruby op are works different ways in some cases.
in this case it will call method -@ of 1(Integer).

but our parser cannot handle these weird case.
because it would not call the method or do something near behavior.

we need to try proto prefix or some other way.

[leto]

Which implementations and versions of Ruby have you verified this on? I assume that whatever MRI does is "right" and everybody else is wrong or at least inconsistent.

[lateau]

on 1.9.3p0 / 1.9.3p125 / trunk

Ruby Draft Specification defines these unary op in general ways(see 11.4.3) and no descriptions about above weird case.
I guess it may be possible. The specification says "the value of the unary-expression is the resulting value of the invocation". And if the resulting value also has -@ method, it will be evaluated again.

you would like to look around rule "args" on parse.y.

see also lastest ruby draft spec:
http://www.ipa.go.jp/osc/english/ruby/