From: kaoru-ruby-lang@...
Date: 2017-01-24T10:05:47+00:00
Subject: [ruby-core:79235] [Ruby trunk Bug#13152] Numeric parsing differences between ruby <-> crystal

Issue #13152 has been updated by Kaoru TAKAHASHI.


Martin D��rst wrote:
> - What do other languages (in particular languages more well known that Cristal) do?

here is METAFONT result.

~~~
This is METAFONT, Version 2.7182818 (TeX Live 2016/Debian) (preloaded base=mf)
**\relax

*show -2**4;
>> 16
*show (-2)**4;
>> 16
~~~

----------------------------------------
Bug #13152: Numeric parsing differences between ruby <-> crystal
https://bugs.ruby-lang.org/issues/13152#change-62653

* Author: Jabari Zakiya
* Status: Rejected
* Priority: Normal
* Assignee: 
* Target version: 
* ruby -v: 
* Backport: 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN
----------------------------------------
I noticed this difference between ruby and crystal when converting a gem.

```ruby
puts   -2**4 -> -16 (ruby) || 16 (crystal)
puts (-2)**4 ->  16 (both)
```

ruby parses `-2**4` as `-(2**4)`, while crystal does `(-2)**4`, which is more intuitive.
This creates need to be careful converting negative number usage from ruby <-> crystal.
(I haven't investigated differences with other languages.)
Using parentheses to explicitly create intended outcomes can overcome this.

However, on the heels of the discussion/decision to not change the default rounding behavior of numerics
in 2.4.0 would it also be worth it to change this parsing behavior to make this more natural
and intuitive, as in crystal?



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