Comment by rektide | Hacker News Reader

Comment by rektide | Hacker News Reader

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why? are you of a 'pointfree' opinion? what are your concerns? https://wiki.haskell.org/Pointfree

personally i detest pointfree syntax. having intermediate values makes it much easier to step through code with a debugger & see what is happening. and it gives the reader some name for what the thing is, which is incredibly useful context. the enablement of pointsfree styles is one of my main concerns about potential pipe operator syntaxes: the various syntaxes that have been raised often introduce implicit variables which are passed, and i greatly fear the loss of clarity pointsfree style brings.

maybe there's something beyond the pointsfree vs not debate here that i'm missing, that makes you dislike the refactored example. personally i greatly enjoy the flatness, the step by step production of intermediate values, each of which can be clearly seen, and then assembled in a last final clear step. that is much more legible to me than one complex expression.

I think it really depends on the language.

In languages that more easily support repl-driven development (e.g. Clojure), I think this is less of an issue. If you have a handful of pure functions, you can quickly and easily execute them via the repl, so you get a lot of clarity as to what those intermediate values look like even if the functions are ultimately used in a more point-free style.

But on the other hand, this would be a nightmare in C# (what I use in my day job). Sure, you can execute arbitrary expressions while debugging C#, but IMO you can't really achieve the same clarity. I'd rather see intermediate values like you suggest since it's easier while debugging, vs a bunch of nested function calls.

I agree that

(1) named intermediate values are sometimes more readable ... though I have examples where it's very hard to come up with names and not sure it helped

(2) debugging is easier.

For (2) though, this IMO is a problem with the debugger. The debugger should allow stepping by statement/expression instead of only by line (or whatever it's currently doing). If the debugger stopped at each pipe and showed in values (2) would mostly be solved. I used a debugger that worked by statements instead of lines once 34 years ago. Sadly I haven't seen once since. It should be optional though as it's a tradeoff. Stepping through some code can get really tedious if there are lots of steps.

Intermediate variables also have the benefit to make not just the last value available in a debugger view, but also previous values (stored in separate variables). Of course, a debugger could remember the last few values you stepped through, but without being bound to named variables, presentation would be difficult.

It's hard to understand which statement the debugger has a break point set to when you can put many breakpoints on the same line

I have tools that can do it, but I'll still have a better time splitting out a variable for it, especially since what I really want is a log of all the intermediate values, so I can replicate what it's doing on paper

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