$_ localization in map:
my @fn_refs = map {sub { print "$_\n"}} qw(foo bar baz);
for (@fn_refs) {
$_->();
}
produces
CODE(0x8105f9c)
CODE(0x8105f9c)
CODE(0x8105f9c)
but
my @fn_refs = map {my $x=$_; sub { print "$x\n"}} qw(foo bar baz);
for (@fn_refs) {
$_->();
}
produces
foo
bar
baz
$_ doesn't get localized to the codeblock in this call to map; assign to a local var first.
Sieve of Eratosthenes in Haskell:
sieve :: [Int] -> [Int] -> [Int]
-- sieve [] xs
-- Assuming that xs is a list of the form [2..max], returns a list of
-- primes between 2 and max. The first parameter is an accumulator
-- list.
--
-- This is a loose interpretation of the Sieve of Eratosthenes; instea
+d
-- of marking composite numbers, we remove them.
sieve p [] = reverse p
sieve p (x:xs) = sieve (x:p) (filter (\t -> (rem t x /= 0)) xs)
More pattern matching in Haskell:
factorial n
| n == 0 = 1
| otherwise = n * factorial (n-1)
Opening too many files?
Perl/mod_perl on shared web servers
Hacking the perl core. Where to begin?
Module writing hints?
•range-based magical autoincrement
Unit Testing Generated HTML
Taken out of Context
BooK
Re: Keeping a Count in foreach
Re: Regular Expressions: Call for Examples
Why are closures cool?
Why are closures cool, continued?
Why Closures?
Closures and scope
for loops, closures
I'm sorry, Mr. Bond
japhy's Obfuscation Review
Re: What goes in a test suite?
Re: My first attempt at obfu (attempted helpfulness)
(tye)Re: How to propose a poll
Be aware of splice
What you refuse to see, is your worst trap
Organising Large Test Suites
S And M -- modifiers, that is...
Guitar neck diagram thingy
Closure on Closures
Composing effective node titles
Consideration overhaul?
Re (tilly) 2: Why Closures?
Re (tilly) 2 (disagree): Another commenting question,
My coding guidelines
Re: Are prototypes evil?
evaluation strategy of perl
MOPT-01 - assumptions and spaces
MOPT-02 - substitution and formal systems
MOPT-03 - identification, part 1
MOPT-04 - identification, part 2
Tripwire tests and future-proofing
Unit Tests and Creative Tension
Editing features for advanced users
Learning to Parrot
When is => ne , (warning rather arcane and possibly totally useless)
The Dynamic Duo --or-- Holy Getopt::Long, Pod::UsageMan!
GetOpt::Long usage style
The Scalar Range Operator
Re: Getopt::Long good style? (tight scoping)
Re: GB, MB, KB and on..
Lessons learned from getting to 100% with Devel::Cover
Funkyness with closures...
RE: Double Interpolation of a String
RFC: perlfeaturedelta
Re: The Purpose of Commenting
Searching BiBTeX
Re: cleaning up code with "do" ?
Obfu Coroutines
Of Symbol Tables and Globs
Perl Monks User Search
My permutor
Blessables -- What Can You Make Into Objects?
May Thy Closures Be Blessed
Multi-Method closures
Re: Fractal Curves: Short & Fast Codes?
Near-free function currying in Perl
|