Feature #12543: explicit tail call syntax: foo() then return

• Status: Closed
• Priority: Normal
• Assignee: matz (Yukihiro Matsumoto)
• Target version: -

[mame (Yusuke Endoh)]

How about introducing a new syntax for tail call?

def foo()
  foo()
end
foo() #=> stack level too deep

def bar()
  bar() then return
end
bar() #=> infinite loop

• no new keyword (cf. goto foo())
• no conflict with any existing syntax
• an experimental patch is available (attached)
• no shift/reduce nor reduce/reduce conflict in parse.y

--
Yusuke Endoh [e-mail]

[mame (Yusuke Endoh)]

• Subject changed from explicit tal call syntax: foo() then return to explicit tail call syntax: foo() then return

[mame (Yusuke Endoh)]

• Related to Feature #6602: Tail call optimization: enable by default? added

[ko1 (Koichi Sasada)]

mame-san:

Do you have use-cases?

[matz (Yukihiro Matsumoto)]

• Status changed from Open to Closed

I am not positive. This may not work under tracing. I am for adding tail-call optimization, but Koichi do not love the idea either.

Matz.