Darren Duncan <[email protected]> wrote on Wed, 24 Aug 2011 11:18:20 PDT:
> Smylers wrote:
>> Could we have underscores and hyphens mean the same thing? That is, Perl
>> 6 always interprets illo-figut and illo_figut as being the same
>> identifier (both for its own identifiers and those minted in programs),
>> with programmers able to use either separator on a whim?
> I oppose this. Underscores and hyphens should remain distinct.
>> That would seem to be the most human-friendly approach.
> I disagree. More human friendly is "if it looks different in any way then it
> is
> different". (I am not also saying that same-looking things are equal, given
> Unicode's redundancy.)
Your mentioning of Unicode is poignant. In Unicode properties, you are not
supposed to have to worry about these things. For example, from UTS#18:
Note: Because it is recommended that the property syntax be lenient
as to spaces, casing, hyphens and underbars, any of the
following should be equivalent: \p{Lu}, \p{lu}, \p{uppercase
letter}, \p{uppercase letter}, \p{Uppercase_Letter}, and
\p{uppercaseletter}
Simillarly, since this applies to property names as well as to property
values, these are all the same:
\p{GC =Lu}
\p{gc =Lu}
\p{General Category=Lu}
\p{General_Category=Lu}
\p{general_category=Lu}
\p{general-category=Lu}
\p{GENERAL-CATEGORY=Lu}
\p{generalcategory =Lu}
\p{GENERALCATEGORY =Lu}
I'll let you permute the RHS on your own. :)
However, I use the opposite of that sort of loose matching of identifiers
in my own code. For example, when I make a named character alias, I always
use lowercase so that it looks different from an official one.
use charnames ":full", ":alias" => {
e_acute => "LATIN SMALL LETTER E WITH ACUTE",
ae => "LATIN SMALL LETTER AE",
smcap_ae => "LATIN LETTER SMALL CAPITAL AE", # this is a lowercase
letter
AE => "LATIN CAPTIAL LETTER AE",
oe => "LATIN SMALL LIGATURE OE",
smcap_oe => "LATIN LETTER SMALL CAPITAL OE", # this is a lowercase
letter
OE => "LATIN CAPITAL LIGATURE OE",
};
I don't make "E_ACUTE" and "eacute" also work there. However, there is a
new ":loose" that does do that, but I suspect I shan't use it, since I use
both "ae" and "AE" differently in existing code.
--tom
