Re: HoA building

Chad Perrin wrote:
John W. Krahn wrote:
M. Lewis wrote:
while (my $ln = <DATA>){
chomp $ln;
my ($prod, $flavor) = split /\s/, $ln, 2;
You probably should use ' ' instead of /\s/ as the first argument to split:

my ($prod, $flavor) = split ' ', $ln, 2;
Ok, but why? Are they not the same?
No, they're not. ' ' is a literal space. /\s/ matches any whitespace.

Actually, on second thought, I seem to recall that ' ' has a meaning in
split() beyond a literal space. Unfortunately, I don't recall exactly
what that is. I've tried looking it up using perldoc -f split and in
several books I have here, and I've tried testing it in simple Perl
scripts. The end result is that I've got nothin' -- except that it so
far seems to be acting just like /\s/.

I'd appreciate it if someone on this list would remind me about the
differences. Both ' ' and /\s/ seem to be matching multiple whitespace
characters when used with split() with no differences, including
matching spaces, tabs, and newline characters.

Example:

$ perl -le "@foo = split ' ', qq( one two three\t\n four ); print
@foo;"
onetwothreefour

$ perl -le "@foo = split /\s/, qq( one two three\t\n four ); print
@foo;"
onetwothreefour


Chad, I've been experimenting with this a bit since your posting. Maybe this will help: (I'm trying to understand the diff too)

perl -le'
my $ln = "one two three four ";
print map " |$_| ", split /\s/, $ln;
print map " |$_| ", split " ", $ln;
'
|one| || |two| || |three| || |four|
|one| |two| |three| |four|


perl -le'
my $ln = "one two three four ";
print map " |$_| ", split /\s+/, $ln;
print map " |$_| ", split " ", $ln;
'
|one| |two| |three| |four|
|one| |two| |three| |four|


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