Jeff King <peff@xxxxxxxx> writes:
> I like all of this, except for the change in the interface of
> Git::config_regexp(). You mention that it's new-ish, and probably not in
> wide use. And I agree that's probably true. But it feels like violating
> a principle of not breaking APIs, and we should stick to that principle
> and not bend it for "well, it's not that old an API".
>
> I'd find it more compelling if it the existing interface was broken or
> hard to avoid changing. But couldn't we just add a new function with the
> extra info (config_regexp_with_values() or something)?
We seem to use it in-tree only once, but we have no control over
what out-of-tree users have been doing.
I do like your proposed name for the fact that it has _with_values
in it; the original gave us only a list of configuration variable
names, and now we are getting name-value tuples.
BUT
I am not sure if I like the new interface, and I do not know if the
the name "config_with_values" is a good match for what it does.
Namely, when a function is described as:
=item config_regexp ( RE )
Retrieve the list of configuration key names matching the regular
expression C<RE>. The return value is an ARRAY of key-value pairs.
I would expect it to return ([key1, value1], [key2, value2], ...),
but the implementation returns (key1, value1, key2, value2, ...),
i.e. a flattened list, if I am not mistaken.
my @cmd = ('config', '--null', '--get-regexp', $regex);
unshift @cmd, $self if $self;
my $data = command(@cmd);
my (@kv) = map { split /\n/, $_, 2 } split /\0/, $data;
return @kv;
We get NUL terminated records, so we first split the entire output
at NULs (to get a list of key-value records). Each key-value record
has the key followed by LF followed by value, so we split it at the
first LF (i.e. a value with an embedded LF would behave correctly)
to extract key and value out of it. But the resulting list is a
flat list with alternating key and value.
The side that works on the returned value of courese knows that it
is getting a flattened list and acts accordingly:
my @kv = Git::config_regexp("^sende?mail[.]");
while (my ($k, $v) = splice @kv, 0, 2) {
push @{$known_config_keys{$k}} => $v;
}
Perhaps it may be more performant than a more obvious and
straight-forward "list of tuples", i.e.
return map { [split /\n/, $_, 2] } split /\0/, $data;
my @kv = Git::config_regexp("^sende?mail[.]");
for my $tuple (@kv) {
push @{$known_config_keys{$tuple->[0]}}, $tuple->[1];
}
but somehow the flattened list felt unnatural at least to a naïve
reader like me.
