From: merch-redmine@...
Date: 2019-08-26T00:58:22+00:00
Subject: [ruby-dev:50837] [Ruby master Bug#14240] warn four special	variables: $; $, $/ $\

Issue #14240 has been updated by jeremyevans0 (Jeremy Evans).

File warn-5-gvars-v3.patch added

nobu (Nobuyoshi Nakada) wrote:
> jeremyevans0 (Jeremy Evans) wrote:
> > > And non-default `$;` and `$,` are warned now.
> > > Do you think these **names** should be warned too?
> > 
> > I don't feel strongly about it.  The `$;` and `$,` are currently run-time warnings based on the specific values passed when setting the values.  akr's previous comment indicated that the warnings of the five variables should be at compile time.
> 
> There are tons of that warnings, and it is not easy to suppress parser warning within the given file only.

Agreed.  I'm fine dropping these compile warnings if the run-time warnings are considered sufficient.

> > One problem with the implementation in my previous patch is that it warns at the wrong location. Switching from `rb_warn` to `rb_compile_warn` fixes that issue.
> 
> It should be `rb_warn1` and `WARN_I(c)` for ripper.
> And a typo `f.line_no` in template/encdb.h.tmpl.

Thanks for the review.  Attached is an updated patch that fixes these issues.

----------------------------------------
Bug #14240: warn four special variables: $; $, $/ $\
https://bugs.ruby-lang.org/issues/14240#change-81004

* Author: akr (Akira Tanaka)
* Status: Open
* Priority: Normal
* Assignee: 
* Target version: 
* ruby -v: 
* Backport: 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN
----------------------------------------
I think the four special variables for separators should be deprecated.

```
$/    input record separator (default argument for "gets")
$\    output record separator ("print" prints it at last)
$,    default separator for Array#join and print
$;    default separator for String#split
```

I feel many program doesn't work if they are set to non-default value.

Since they are global, not thread local,
we can not change these variables safely in a multi threaded program.

So, I think we should warn them (and delete them in future).





---Files--------------------------------
warn-5-gvars.patch (2.31 KB)
warn-5-gvars-v2.patch (5.44 KB)
warn-5-gvars-v3.patch (5.4 KB)


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