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by nnq 2472 days ago
What is illegible about that?!

It just says, in code: "replace each line of text with itself prefixed by a number of spaces equal with half of the difference between its length and the length of the longest line in the text".

It's like the most obvious way to think about this particular problem!

Now, how well this scales to different problems, and especially to problems where mutation is a natural way to think about things... that's a different problem and part of the reason I'm not that much in love with extremist functional programming. Mutation has its place and the monadic abstraction is something I dislike.

But for simple examples like this pure FP rocks and is very readable and intuitive!
1 comments
marcosdumay 2472 days ago
As usual in FP code, the order of your words are completely different from the order things appear in the code. Also, most developers aren't used to concise function declarations (yeah, even with JS pushing them), what further adds to the problem.

This is not something people with no experience on FP can read easily. Now, calling it illegible strongly implies that people with no FP experience are the metric one should code for, what is perfectly valid if you are at a company aiming to hire cheap coders, but not something to brag about.

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nnq 2472 days ago
Order of words is not that relevant, in English I can say instead of the above:

"take each line of code [map ... xs] and replace it with [\x -> ...] a number of spaces equal to half the maximum line width [replicate (div (n - length x) 2) ' '] prepended to it [... + x]"

All languages have passive voice and other tools so you can make the order of words be whatever you'd want for customizable emphasis while keeping meaning the same.

Sure the order for arguments for `map` may not be the most intuitive, but that doesn't make things harder. See ReasonML for an example of functional programming with regular C-like syntax.

Now, if you want to see hard to read functional code, look into code abusing point free style (I'm not even sure there is a fine way to use it at all...), plus mind bending types (usually to satisfy some monadic style abstractions), plus over-currying stuff all over the place.

But the snippet above is only unreadable for people who stubbornly refuse to invest a couple hours of their time into learning a new notation for things! Heck, you can even translate it almost 1-to-1 to modern Javascript, or even add an extra function name and some more sensible variable names to make things more readable while keeping it functional:

    function alignCenter(lines) {
      let width = Math.max(...lines.map(ln => ln.length));
      let getPadding = len => ' '.repeat(Math.max(0, (width - len) / 2));
      return lines.map(ln => getPadding(ln.length) + ln);
    }
...the above is more like something I'd actually let pass code review in real life :)
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