Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl-Sensitive Sunglasses
 
PerlMonks  

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??

It will work fine for sub parameters. You can provide a list of keys as a second parameter to lock_keys:

sub whatever { my %params = @_; lock_keys %params, qw/ key1 key2 key3 /; say "Got key1" if $params{key1}; # ok say "Got key2" if $params{key2}; # ok say "Got key3" if $params{keye}; # Oops - BOOM! } whatever key2 => $value2; whatever keyq => $value1; # Hash has key 'keyq' which is not in the ne +w key set

For example, I use the following for parsing command-line options in my scripts:

use Getopt::Long qw/:config bundling/; use Hash::Util qw/ lock_keys /; our %OPT; my @OPT_SPEC = qw/ help|h version noact|no-act|dry-run DEBUG output|o= +s /; GetOptions \%OPT, @OPT_SPEC or ($OPT{help} = 1); lock_keys(%OPT, map /^(\w+)/, @OPT_SPEC);

Update 2: A diligent Anonymous monk actually tested this code (actually executing proposed code - what a concept) and pointed out that the initial lock_keys suggestion is sufficient. Updated the comments in the code above to reflect this.

Update: Add example where lock_keys is not quite sufficient... One could solve this in a couple ways without changing how whatever is called: Anonymous monk make all this unnecessary

# Option 1: use Params::Validate # Option 2: sub whatever { my @param_keys = qw/ key1 key2 key3 /; my %params = @_; $params{$_} //= undef for @param_keys; die "Invalid usage" if @param_keys != (keys %params); lock_keys %params; # ... } # Option 3: sub whatever { my %expected_params = map +($_,1), qw/ key1 key2 key3 /; my %params = @_; for (keys %params) { die "whatever: Unexpected named parameter $_" unless exists $e +xpected_params{$_}; } lock_keys %params, keys %expected_params; # ... }

Good Day,
    Dean


In reply to Re^4: Benifits of using hash rather than number of variables? by duelafn
in thread Benifits of using hash rather than number of variables? by tart

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others scrutinizing the Monastery: (8)
    As of 2015-07-03 20:20 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      The top three priorities of my open tasks are (in descending order of likelihood to be worked on) ...









      Results (56 votes), past polls