Re^2: map a hash with a default value or exclude

or instead of using the ?: in the "decoding" map for the elimination case you could instead use a grep:

%{$self->{info}} = map {@$_} grep {defined $_->[1]} map {chomp; [split
+'='];} <$fh>;
[download]

In any case generating the array ref doesn't actually seem to be a win in terms of succinctness or comprehensibility.

True laziness is hard work

Comment on Re^2: map a hash with a default value or exclude Download Code

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Re^3: map a hash with a default value or exclude by PrakashK (Pilgrim) on Sep 13, 2011 at 19:09 UTC
Yet another way, using the 3-argument form of split, which guarantees that the input string is split into two parts and no more or less. The second part would be a string of length 0, instead of an undefined value. `%{$self->{info}} = map {@$_} grep {$_->[1]} map {chomp; [split '=', $_ +, 2];} <$fh>;` [download] I prefer this form of split in handling `key=value` type strings, since it handles the cases where a value could have an embedded '=' (`PASSWORD=blah=argh!`), whereas the shorter one-(or, two-)argument forms would return truncated values. Yet another alternative, using only one map: `%{$self->{info}} = map {chomp; my ($k, $v) = split '=', $_, 2; $v ? ($ +k => $v) : (); } <$fh>;` [download] If we want to supply default values: `# assuming default values are in %defaults %{$self->{info}} = map {chomp; my ($k, $v) = split '=', $_, 2; $k => $ +v \|\| $defaults{$k}; } <$fh>;` [download]	[reply] [d/l] [select]

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Re^3: map a hash with a default value or exclude
by PrakashK (Pilgrim) on Sep 13, 2011 at 19:09 UTC

Yet another way, using the 3-argument form of split, which guarantees that the input string is split into two parts and no more or less. The second part would be a string of length 0, instead of an undefined value.

%{$self->{info}} = map {@$_} grep {$_->[1]} map {chomp; [split '=', $_
+, 2];} <$fh>;
[download]

I prefer this form of split in handling key=value type strings, since it handles the cases where a value could have an embedded '=' (PASSWORD=blah=argh!), whereas the shorter one-(or, two-)argument forms would return truncated values.

Yet another alternative, using only one map:

%{$self->{info}} = map {chomp; my ($k, $v) = split '=', $_, 2; $v ? ($
+k => $v) : (); } <$fh>;
[download]

If we want to supply default values:

# assuming default values are in %defaults
%{$self->{info}} = map {chomp; my ($k, $v) = split '=', $_, 2; $k => $
+v || $defaults{$k}; } <$fh>;
[download]

[reply]
[d/l]
[select]