Array::Autojoin -- arrayrefs that stringify as join(", ", @$it)
use Array::Autojoin; my $headword = "biscocho"; my $gloss = mkarray("cookie", "biscuit"); print "$headword\: $gloss.\n"; # Prints "biscocho: cookie, biscuit.\n";
This extremely short and simple module provides one exported function,
mkarray( ...items... ), which makes an arrayref (containing those items) belonging to a class that does nothing other than specifying to Perl that when you want the string value of that arrayref, instead of giving something like "ARRAY(0x171568f)", it returns a happy string consisting of
join(', ', @$arrayref).
Also, rather incidentally:
* In boolean context (like
print "Yow!" if $arrayref), the boolean value is true iff the reference is to an array containing at least one boolean-true value. So:
mkarray() is boolean-false -- no values at all mkarray('','','','') is boolean-false -- no values are true mkarray('',0,undef ) is boolean-false -- no values are true mkarray('', 123 ) is boolean-true -- there's a true value (123) mkarray("PIE" ) is boolean-true -- there's a true value ("PIE")
* In numeric scalar context -- where
join(', ', @$arrayref) would be unhelpful -- you get the numeric value of the first item (or zero if there's no items):
my $z = mkarray(3,7,19,63,30); print 39 + $z; # numeric $z yields 3, so this prints 42
* ".=" is overloaded to append to the last element (or in the case of an empty array, to create a new element):
my $headword = "biscocho"; my $gloss = mkarray("cookie", "biscuit"); $headword .= "!"; $gloss .= "!"; print "$headword\: $gloss\n"; # Prints "biscocho!: cookie, biscuit!\n" push @$gloss, "hooboy"; # see, can still treat it like a normal array ref printf "Count of glosses: %d\n", scalar(@$gloss); # Prints: Count of glosses: 3 print "Gloss bits: ", map("<$_> ", @$gloss), "\n"; # Prints: Gloss bits: <cookie> <biscuit!> <hooboy>
* If you want to know how this class works, look at its source, and cf. the "overload" man page.
* If you want a class that works sort of like this one, but different, then feel free to make your own, using this class as a model.
* Remember, once you stringify something, it's not an object anymore!
use strict; my $gloss = mkarray("cookie", "biscuit"); $gloss = "<" . $gloss . ">"; # and shazam, it's stringified, and the string gotten from # putting "<" and ">" around it, is put back into $gloss, # replacing the arrayref. print "It's $gloss!\n"; # It's <cookie, biscuit>! printf "Count of glosses: %d\n", scalar(@$gloss); # DIES with: Can't use string ("<cookie, biscuit>") as an ARRAY # ref while "strict refs" in use [at ...]
Copyright 2001 Sean M. Burke.
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
This program is distributed in the hope that it will be useful, but without any warranty; without even the implied warranty of merchantability or fitness for a particular purpose.
Sean M. Burke, <email@example.com>