Re: Neater way to declare variables
On Jan 8, 3:56 am, andrew.tayl...@hmrcaspire.com (Andrew Taylor)
wrote:
> Hello
>
> I have a script that is (at one point) reading through a file. The file
> is processed line by line and each line split into an array like so:
>
> while (<$TESTFILE>)
>
> {
>
> my $cur_line=$_;
>
> chomp ($cur_line);
>
while (my $cur_line = <$TESTFILE>) {
chomp $cur_line;
> my @split_line = split( /$t_delim/, $cur_line );
>
> # In a number of places, I have code that looks like the following.
>
> my $default_type;
>
> if( $split_line[0] eq "DEFAULT_INPUT" )
>
> {
>
> $default_type = "INPUT";
>
> }
>
> if ( $split_line[0] eq "DEFAULT_OUTPUT" )
>
> {
>
> $default_type = "OUTPUT";
>
> }
>
snip
>
> This works OK, but I'm trying to avoid declaring variables seperately
> from assigning them (wherever possible), and trying to keep the size of
> the script down without losing human legibility.
>
> Is there a neater/cleverer way of doing this?
>
my $default_type = $split_line[0] =~ /INPUT/ ? 'INPUT' : 'OUTPUT';
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Re: Neater way to declare variables
From: "Taylor, Andrew \(ASPIRE\)"
> I have a script that is (at one point) reading through a file. The file
> is processed line by line and each line split into an array like so:
>
> while (<$TESTFILE>)
> {
> my $cur_line=$_;
> chomp ($cur_line);
while (defined(my $cur_line = <$TESTFILE>)) {
chomp($cur_line);
> my $default_type;
> if( $split_line[0] eq "DEFAULT_INPUT" )
> {
> $default_type = "INPUT";
> }
> if ( $split_line[0] eq "DEFAULT_OUTPUT" )
> {
> $default_type = "OUTPUT";
> }
my $default_type = do {
if ($split_line[0] eq "DEFAULT_INPUT" ) {
"INPUT"
} elsif ($split_line[0] eq "DEFAULT_OUTPUT" ) {
"OUTPUT"
}
};
Jenda
= je...@krynicky.cz === http://Jenda.Krynicky.cz =
When it comes to wine, women and song, wizards are allowed
to get drunk and croon as much as they like.
-- Terry Pratchett in Sourcery
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Re: Neater way to declare variables
On Thu Jan 08 2009 @ 11:56, Taylor, Andrew (ASPIRE) wrote:
> # In a number of places, I have code that looks like the following.
>
>
>
> my $default_type;
>
>
>
> if( $split_line[0] eq "DEFAULT_INPUT" )
>
> {
>
> $default_type = "INPUT";
>
> }
> This works OK, but I'm trying to avoid declaring variables seperately
> from assigning them (wherever possible), and trying to keep the size of
> the script down without losing human legibility.
You can use the statement modifier conditional form, in which case, the if
follows the assignment. Many people find this easier to read for such a simple
test:
my $default_type = "INPUT" if $split_line[0] eq "DEFAULT_INPUT";
See here for more: http://perldoc.perl.org/perlsyn.html#Statement-Modifiers
Hope this helps, T
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Re: Neater way to declare variables
On Thu, 2009-01-08 at 11:56 +, Taylor, Andrew (ASPIRE) wrote:
> This works OK, but I'm trying to avoid declaring variables seperately
> from assigning them (wherever possible), and trying to keep the size
> of
> the script down without losing human legibility.
>
> Is there a neater/cleverer way of doing this?
>
Programming is as much about organization and communication as it is
about coding. It is possible to write your code too densely to be
easily understood.
However you can shorten some of your code.
while (<$TESTFILE>)
{
chomp;
my @split_line = split( /$t_delim/, $_ );
my %Default_types = (
DEFAULT_INPUT => 'INPUT',
DEFAULT_OUTPUT => 'OUTPUT',
);
$default_type = $Default_types{$split_line[0]} || undef;
--
Just my 0.0002 million dollars worth,
Shawn
Programming is as much about organization and communication as it is about
coding.
"It would appear that we have reached the limits of what it is possible to
achieve with computer technology, although one should be careful with such
statements, as they tend to sound pretty silly in 5 years."
--John von Neumann, circa 1950
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Neater way to declare variables
Hello
I have a script that is (at one point) reading through a file. The file
is processed line by line and each line split into an array like so:
while (<$TESTFILE>)
{
my $cur_line=$_;
chomp ($cur_line);
my @split_line = split( /$t_delim/, $cur_line );
# In a number of places, I have code that looks like the following.
my $default_type;
if( $split_line[0] eq "DEFAULT_INPUT" )
{
$default_type = "INPUT";
}
if ( $split_line[0] eq "DEFAULT_OUTPUT" )
{
$default_type = "OUTPUT";
}
# processing continues...
# more stuff here
# blah blah blah
# etc. etc.
}
This works OK, but I'm trying to avoid declaring variables seperately
from assigning them (wherever possible), and trying to keep the size of
the script down without losing human legibility.
Is there a neater/cleverer way of doing this?
Cheers
Andy Taylor
Andrew Taylor | Capgemini | Telford
ASPIRE Data Warehouse Support
T : +44 (0)1952 430684 | www.capgemini.com
