Which I have spoke of, whereunto your levy
Must be supplyant: the words of your commission
Will tie you to the numbers and the time
Of their despatch."
-- Shakespeare, Cymbeline
Act III, Scene VIII, Lines 12.2 - 16.1
Zipping is a very simple concept from higher order functions which does not get talked about much.
With a zip you have a number of collection which you wish to apply a function against each matching member in order to produce a single "zipped" collection.
In general:
GIVEN a function f
FOREACH x_i in X, y_i in Y, ...
r_i = f(x_i, y_i, ..)
GIVING r_i in R
The function f is the "zipper", while X, Y, ... are the collections being zipped with R being the zipped result.
A simple example with 2 collections:
Let's use Add as the "zipper", [1, 2, 3] as the first collection, and [10, 20, 30] as the second collection.
We see that this gives us the resulting collection of [11, 22, 33].
What should happen if the first or second collection has a different number of elements?
OR
We'll look at what C#, Clojure, and Haskell do in these cases.
We see that they each have a resulting collection as large as the smallest input collection and simply just ignore the rest of the input in the larger collection. There you have it a very simple introduction to Zip.
Zipping is a very simple concept from higher order functions which does not get talked about much.
With a zip you have a number of collection which you wish to apply a function against each matching member in order to produce a single "zipped" collection.
In general:
GIVEN a function f
FOREACH x_i in X, y_i in Y, ...
r_i = f(x_i, y_i, ..)
GIVING r_i in R
The function f is the "zipper", while X, Y, ... are the collections being zipped with R being the zipped result.
A simple example with 2 collections:
Let's use Add as the "zipper", [1, 2, 3] as the first collection, and [10, 20, 30] as the second collection.
We see that this gives us the resulting collection of [11, 22, 33].
What should happen if the first or second collection has a different number of elements?
OR
We'll look at what C#, Clojure, and Haskell do in these cases.
We see that they each have a resulting collection as large as the smallest input collection and simply just ignore the rest of the input in the larger collection. There you have it a very simple introduction to Zip.
