For Style Loops

Idio supports a for each style of looping over compound values. for-each is a simple wrapper around map where map collects results and for-each doesn’t.

They both take the form, map func list+, where func should take as many arguments as there are lists in list+.

simple-for-each.idio

define (foo p) {
  printf "%s is for %s\n" (ph p) (pht p)
}

data := '((a "apple")
          (b "banana"))

for-each foo data

$ idio simple-for
a is for apple
b is for banana

Defining a specific one-shot function is tiresome:

simple-for-2.idio

data := '((a "apple")
          (b "banana"))

for p in data {
  printf "%s is for %s\n" (ph p) (pht p)
}

$ idio simple-for-2
a is for apple
b is for banana

A variation is to walk down each list simultaneously by passing multiple variables as a list, one variable per list:

simple-for-3.idio

data := '((a "apple")
          (b "banana"))

for (e1 e2) in data {
  printf "%s and %s\n" e1 e2
}

$ idio simple-for-3
a and b
apple and banana

Notice that the lists are walked in parallel which is orthogonal to the previous example.

Last built at 2024-05-21T06:11:39Z+0000 from 77077af (dev) for Idio 0.3