re: Types of Loops VIEW POST


Your "action" loop is normally called mapping, used for either side effects (this is your "action") or "transforming" sequences, see here for an example clhs.lisp.se/Body/f_map.htm.

Then there is your "count", which could be seen as a special case of reduce. Reduce is used to apply a function to a sequence using an operator, see clhs.lisp.se/Body/f_reduce.htm.

Btw, Ruby's array class (ruby-doc.org/core-2.2.0/Array.html) is a good source of "loop" operations. It contains "map", "reduce" and also other common loop operations as "include?" (your find), "delete", "drop", "each" (often used for your action), "keep_if", "reverse", "sort", "shift", "slice" amd much more...


I agree. Those operations have better names and are part of larger use-cases or patterns.
The problem with those better names is that for beginners, they mean nothing. If you go to a beginner, who never ever coded before, and tell them to "reduce" an array, they will just stare at you wide-eyed.

The C++ <algorithm> header is also a great source for such operations. But again - too advanced.


Personally my favorite source of names is Haskell. In the case of loops you can get them from Data.List.

The abstract names like "map", "fold" and "scan" are definitely too advanced for newcomers. But the more specialized ones like "reverse", "take", "drop", "filter", "splitAt", "concat", "sum", etc. are self-explanatory. I really wish I've learned about these names earlier, and so far these names are pretty general across languages I've dabbed into.

I prefer "fold" to "reduce" because I don't know what "reduce" wants to convey. "Fold" very vividly conveys that the operation folds the whole list into something else interesting, part by part.

I've also introduced the Java documentation early and showed my students and schoolmates how to explore it by searching and reading list of methods. It doesn't take much for them to start exploring themselves.

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