> Just to be be clear, my idea is the second line is wrong, and it
should flag that one as a problem....
Oh, but if you go literally with the code I posted, *both* the first
and second lines have incorrect descriptions, and only the third line
("corn dogs") matches.
(That was a mistake when I wrote it up, but whatever.)
On 6/14/20, Joseph Brenner <doom...@gmail.com> wrote:
> Well, with the first one it rejects all of my lines, and with the
> second one it passes all of them.
>
> Just to be be clear, my idea is the second line is wrong, and it
> should flag that one as a problem....
>
>
>
> On 6/14/20, yary <not....@gmail.com> wrote:
>> https://docs.raku.org/language/regexes#Regex_interpolation gave me some
>> ideas
>>
>> Try matching against / (^P\d+) \s+ %products{$0} /
>>
>> This one also works, in a roundabout way
>> / (^P\d+) \s+ {"%products{$0}"} /
>> -y
>>
>>
>> On Sun, Jun 14, 2020 at 4:44 PM Joseph Brenner <doom...@gmail.com> wrote:
>>
>>> In part because of the recent discussion here, I decided to
>>> play around with using Raku code embedded in a regexp.
>>> I came up with a contrived example where I was going to
>>> examine a product listing in a text block to see if the product
>>> descriptions matched the product codes. The valid associations
>>> I have in a hash, so I'm (1) matching for product codes; (2)
>>> using embedded code to look-up the associated description in the hash;
>>> (3) using the returned description inside the regex.
>>>
>>> my %products = ( 'P123' => "Green Labels That Say Magenta",
>>> 'P666' => 'Darkseid For President Bumpersticker',
>>> 'P912' => "Corn dogs",
>>> );
>>>
>>> my $text = q:to/END/;
>>> P123 Viridian Green Label Saying Magenta
>>> P666 Yoda puppets
>>> P912 Corn dogs
>>> END
>>>
>>> my @lines = $text.lines;
>>> say @lines;
>>>
>>> for @lines -> $line {
>>> say "checking line: $line";
>>> ## This line works, but it's not a complete solution:
>>> if $line ~~ / (^P\d+) \s+ <{ %products{$0}.subst(/\s+/, '\s', :g) }>
>>> /
>>> {
>>> say "Matched, line looks good";
>>> }
>>> else {
>>> say "NO: bad line.";
>>> }
>>> }
>>>
>>> I'd thought that a line like this would work:
>>>
>>> if $line ~~ / (^P\d+) \s+ <{ %products{$0} }> / {
>>>
>>> The trouble though is I've got spaces inside the descriptions,
>>> so if the returned string is treated as a regexp, I get these
>>> warnings:
>>>
>>> Potential difficulties:
>>> Space is not significant here; please use quotes or :s
>>> (:sigspace) modifier (or, to suppress this warning, omit the space, or
>>> otherwise change the spacing)
>>>
>>> Reading a bit, I thought this should work
>>>
>>> if $line ~~ / (^P\d+) \s+ $( %products{$0} ) / {
>>>
>>> That's supposed to use the return string as a literal match.
>>> Instead I get a lot of strange messages like:
>>>
>>> Use of Nil in string context in regex
>>>
>>> Flailing around I considered lots of variations like this:
>>>
>>> if $line ~~ / (^P\d+) \s+ Q[<{ %products{$0}}>] / {
>>>
>>> But I think that ends up treating everything inside the Q[]
>>> literally, so you never do the hash lookup.
>>>
>>> Another thing that might solve this problem is some sort of
>>> regexp quote function I could use inside the code before
>>> returning the string, but I don't know what that would be...
>>>
>>
>
