From: Robert Klemme <shortcutter@...>
Date: 2009-12-10T18:58:04+09:00
Subject: Re: which is better?

2009/12/10 Wybo Dekker <wybo@servalys.nl>:
> Robert Klemme wrote:
>
>> And then there's also
>>
>> irb(main):001:0> "123ab".tr "0-9", ""
>> => "ab"
>> irb(main):002:0> "123ab".tr! "0-9", ""
>> => "ab"
>
> But why no parentheses?:
> irb
>>> $-w=true
> => true
>>> "abcd1234".gsub! /\d+/,''
> (irb):13: warning: ambiguous first argument; put parentheses or even spaces
> => "abcd"
>>> "123ab".tr! "0-9",""
> => "ab"
>
> what is the ambiguity in the first case, and why is there no warning in the
> second case?

Seems to be related to the regexp:

10:56:19 $ ruby19 -wce 'o.gsub! /\d/, ""'
-e:1: warning: ambiguous first argument; put parentheses or even spaces
Syntax OK
10:56:42 $ ruby19 -wce 'o.gsub! "d", ""'
Syntax OK
10:56:50 $ ruby19 -wce 'o.gsub!(/\d/, "")'
Syntax OK
10:57:01 $

Why? No idea.

Cheers

robert


-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/