[ruby-core:93788] [Ruby master Bug#16004] Kernel#lambda captured with Kernel#method doesn't create lambdas

Issue #16004 has been updated by shevegen (Robert A. Heiler).


I think this requires matz to determine which behaviour is the valid or the
better one (as from the other linked discussion too).

I myself almost never use lambdas and only very rarely proc deliberately 
so (via e. g. Proc.new or proc {}), but from the syntax example given by
alanwu, I actually agree that I would have assumed there to be a lambda.

At the same time, though:

    method(:lambda).call

without {} leads to

    ArgumentError (tried to create Proc object without a block)

so I think it just needs consistency either way (and perhaps 
may be backwards incompatible if changed?).

Either way I agree with alanwu here at the least from my initial
assumption/expectation.

benoit wrote:

> Like in #15973, I think this is just an incorrect usage of #lambda.

Well, we can say that of course, but then we have to look at example(s)
given by alanwu like this one here, and I think his example makes
sense (to me). But admittedly I so rarely use lambdas or procs
deliberately that it would not affect me either way; I am using
ruby mostly in an oldschool OOP fashion (aside from blocks of course,
which I use a LOT, so I sort of use procs too, I guess) where I 
rarely have procs/lambdas directly within the code itself. I used
to use them in the past in ruby-gtk + callbacks, but I found it a
bit too cumbersome compared to just using objects and methods 
directly. .call() can still be useful of course, e. g. as rack 
showed.


----------------------------------------
Bug #16004: Kernel#lambda captured with Kernel#method doesn't create lambdas
https://bugs.ruby-lang.org/issues/16004#change-79443

* Author: alanwu (Alan Wu)
* Status: Open
* Priority: Normal
* Assignee: 
* Target version: 
* ruby -v: ruby 2.7.0dev (2019-07-15T00:58:26Z master 223854ebe8) [x86_64-linux]
* Backport: 2.5: UNKNOWN, 2.6: UNKNOWN
----------------------------------------
`ruby -e 'p method(:lambda).call{}.lambda?'` prints false on 2.3.x-master(223854ebe8).
I think it should create lambdas.




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