I don’t need conditionals either

While reading John A De Goes’ blog post about how to rid functions of variables tied to conditions, I wondered how I would do that in Perl 6.

The objective of his first example is to compare two strings case insensitive. Easy!

say "abc".fc eq "Abc".fc;

And then my mind started to wander off. I took a mental note and finished reading about ridding of ifs. Returning to my mental note I concluded: “There must be a nicer way to write that!”. It’s Perl 6 after all.

How about the function combinator?

my &ieq = &infix:<eq> ∘ &fc;

That didn’t work because ∘ cares about the number of arguments of its first operand but doesn’t about its second. What I actually need would be a loop over the two strings calling .fc on each of them.

my @l = <abc Abc>>>.fc;

So I tried to fix the function combinator resulting in a gist. It’s now special cased for the 2nd operand to have just one argument. I felt a bit uneasy about that solution. Maybe because it would require a PR to Rakudo.

And then I realised that I might just bind a pointy to a operator name. I didn’t doc that so I checked and we indeed missed that spot. Short test via camelia.

my &infix:<foo> := -> {}

That worked. So let’s have a case insensitive string compare infix operator.

my &infix:<ieq> = -> |l { [eq] l>>.fc };
say "abc" ieq "Abc";
# OUTPUT«True␤»

Nice, short and no conditionals that could confuse John.