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Re: can understand one line of code

by BrowserUk (Pope)
on Dec 19, 2012 at 15:24 UTC ( #1009577=note: print w/ replies, xml ) Need Help??


in reply to can understand one line of code

Break it down:

  1. grep( expression, @{ ... } )
  2. The expression  s#$#$RegObj->{DELIM}#

    start with 's', so it is a substitution.

    The #s are delimiters so the two sides are: $ and $RegObj->{DELIM}

    So it is substituting the module defined delimiter for any '$'s every end of line.

  3. The array: @{ $RegObj->{MEMBERS}= [ @{$RegObj->{SUBKEYS}} ] }

    Contains an assignment: $RegObj->{MEMBERS}= [ @{$RegObj->{SUBKEYS}} ]

    It copies the array of subkeys : @{ $RegObj->{SUBKEYS} } into an anonymous array [ ... ]

    And assigns its reference to $RegObj->{MEMBERS} = ...

    Then it dereferences that to supply the subkeys to grep.

Thus, that one line is equivalent to:

my @temp = @{ $RegObj->{SUBKEYS} }; $RegObj->{MEMBERS} = \@temp; grep s[$][$RegObj->{DELIM}], @temp;

Without the need for @temp; but less efficient.


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