make code into a 1 liner 4

[onomo]

Hi all, i have this code to extract all words beginning with an "@" character, it works perfectly fine:

push @text,map(/(?<!\w)@\w+/g, @words);

but, i need to avoid adding replicas of the same word. my space is very limited and i was wondering if it was possible to do this in a 1 liner, extract those words and avoiding replicas?


thanks!

 

[Annihilannic]

I thought you should be able to do something like this (loosely based on some map examples on perldoc -f map):

%hash = map { /(?<!\w)@\w+/g => 1 } @words;

And then print the hash keys out... but it doesn't work. I'd be keen to know why; I'm assuming it's not handling the situation where the expression doesn't match correctly and adding a single value to the list rather than a key, value pair?

Annihilannic.

 

[rharsh]

Huh? Space is limited? This isn't homework is it? Combining all this into one line seems like an unnecessary complication.

Anyway, here's one way to do it:

push @text, map {keys %{$_}} {map {$_, 1} grep(/^@/, @words)};

Since that code uses a hash, the order of the elements cannot be guaranteed.

 

[1DMF]

rhash, does your method not omit duplicates, but simply overwrites any duplicate with the same key/value, in essence only leaving you with one key/value pair?

"In complete darkness we are all the same, only our knowledge and wisdom separates us, don't let your eyes deceive you."

"If a shortcut was meant to be easy, it wouldn't be a shortcut, it would be the way!"

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[rharsh]

1DMF, you're right - that is pretty much the case. An anonymous hash is created with keys that are all the elements from @words[] that match the criteria in the grep expression. So what gets added to @text[] are the keys from that anonymous hash -- the unique elements returned from the grep.

Wasn't that what the OP asked for? Or am I missing something?

 

[Annihilannic]

Yep, that's what they were looking for.

What incorrect assumptions was I making in my attemp, rharsh?

Annihilannic.

 

[1DMF]

Thanks guys, just wanted to be sure I'd got my head round the code and understood exactly what was happening.

Have some stars

"In complete darkness we are all the same, only our knowledge and wisdom separates us, don't let your eyes deceive you."

"If a shortcut was meant to be easy, it wouldn't be a shortcut, it would be the way!"

Google Rank Extractor -> Perl beta with FusionCharts

 

[MillerH]

I thought you should be able to do something like this (loosely based on some map examples on perldoc -f map):

%hash = map { /(?<!\w)@\w+/g => 1 } @words;

@Anni,

The results of that particular regex will be an array, so you must instead use two maps to create the hash:

%hash = map {$_ => 1} map {/(?<!\w)@\w+/g} @words;

- Miller

 

[Annihilannic]

Thanks!

Annihilannic.