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Comment by elsurudo | Hacker News Reader

Point taken that it is ok to use i, x, y, z sometimes (eg. when iterating), but the notion 'a meaningless parameter that is just a variable' doesn't really exist... if it's meaningless, why are you saving it?

Only other use case I can think of is doing metaprogramming or some sort of templating where you have a variable, but might no even know what it represents, because it isn't your concern.

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What about implementing something like map for lists? You know literally nothing about the values and the function except for their types.

    map :: (a -> b) -> [a] -> [b]
    map f [] = []
    map f (a:as) = f a : map f as

Personally I don't see any reason to use longer names than f, a, and as because you can't add any additional information.

You might say "well I don't write code like that", and I don't have any answer for you. But I find I write a fair amount of generic code.

> you can't add any additional information

Well you could...

    map transforming_function (element:rest_of_list) = transforming_function element : map transforming_function rest_of_list

...but the cost in terms of loss of brevity would far outweigh a benefit that would only accrue to complete beginners, who would be better served by comments and test cases.

> if it's meaningless, why are you saving it?

Because you are writing abstract code.

Odds are that a lot of your code is better done abstract, and only fully specified in a short context.

A variable can be a substitute for a longer expression for which a name/description is unnecessary because the expression itself is self-explanatory. The substitution with a (essentially meaningless) short name just makes repeated use of that expression more readable. Using a long, descriptive name would defeat the point.

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