Feature #17361: lambda(&block) does not warn with lazy proc allocation

• Status: Closed
• Assignee: ko1 (Koichi Sasada)
• Target version: -

[znz (Kazuhiro NISHIYAMA)]

In NEWS,

        * Kernel#lambda now warns if called without a literal block.
          [[Feature #15973]]

But the following code from https://docs.ruby-lang.org/ja/latest/method/Kernel/m/lambda.html (https://github.com/rurema/doctree/blob/495868c466c97c9bcca28d64d6ce0d68350de3e2/refm/api/src/_builtin/functions#L2436-L2441) does not warn.

def foo &block
  lambda(&block)
end

it = foo{p 12}
it.call #=> 12

Once block assign to a local variable, it warns.

def foo &block
  b = block
  lambda(&b)
end

it = foo{p 12}
it.call #=> 12

[znz (Kazuhiro NISHIYAMA)]

• Related to Feature #15973: Let Kernel#lambda always return a lambda added

[ko1 (Koichi Sasada)]

• Assignee set to ko1 (Koichi Sasada)

[ko1 (Koichi Sasada)]

• Status changed from Open to Closed

Applied in changeset git|b53ccb9c69abd24e3bdad66cbe4c7e7480eaef16.

---

show deprecation warning correctly for lambda(&b)

lambda(&b) where b is given block of method (like: def foo(&b))
should warn correctly.
[Feature #17361]

Also labmda(&labmda_block) or lambda(&:to_s) (Symbol#to_proc)
should not warn (but I'm not sure who cares about it).