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Postings from August 2013
On 15 August 2013 20:10, Johan Vromans <jvromans@squirrel.nl> wrote: > demerphq <demerphq@gmail.com> writes: > >> This aside I think there is a real problem with this proposal. It >> breaks the original model of sigils completely. IMO sigils are hard >> enough that completely breaking the original intent is not helpful, no >> matter how sweet your tooth is for the syntactic sugar it offers. >> >> My understanding of the Perl5 sigils is that they are meant to denote >> the type of result that will be _returned_*. >> >> We write: >> >> $thing= $foo[1]; >> >> and not >> >> $thing= @foo[1]; >> >> because the former tells us we are getting back a scalar. The latter >> says we are getting back a list. >> [...] >> * I looked for documentation to back this up, and the best I could >> find was in perlfaq4. I suspect that it is better documented in one of >> the Perl books by Larry. > > From the first Camel: > > You'll note that we didn't have to tell Perl what kind of variable > $answer is. That's because the $ character itself tells Perl that > $answer can hold a single value, which can be either a string or a > number. We call this a scalar variable. > > Also: > > We use the $ in $ARRAY[SCALAR] to indicate that we are selecting a > scalar value even though it's coming from an array that is named > @ARRAY. That will be confusing to you until you discover that you can > use @ in @ARRAY[LIST] as the notation for array slices, and you figure > out that the $ or @ is controlling the context of the subscript. > > Camel I didn't mention sigils, it called them "funny characters": > > Some consider that having the variables all start with funny > characters makes Perl an ugly language. [...] > > Camel IV was the first book to call them "sigils". > > Note that we do not have to be very specific about kind of variable > $phrase is. The $ character tells Perl that phrase is a scalar > variable, that is, one con- taining a singular value. An array > variable, by contrast, would start with an @ character. [...] Perl has > some other variable types, with unlikely names like “hash”, “handle”, > and “typeglob”. Like scalars and arrays, these types of variables are > also preceded by funny characters, commonly known as sigils. > > Also, from Camel IV: > > Array subscripts are enclosed in square brackets [like this], so if > you want to select an individual array element, you would refer to it > as $home[n], where n is the subscript (one less than the element > number) you want. See the example that follows. Since the element you > are dealing with is a scalar, you always precede it with a $. > > Note the last sentence. This is fundamental to Perl as we know it, and > also one of the fundamental differences between Perl and Perl6. Thanks, so this proposal will make a lie out of every Camel book in existence. That is not a good thing. Yves -- perl -Mre=debug -e "/just|another|perl|hacker/"Thread Previous | Thread Next