| 12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455 |
- discard """
- output: '''30
- 60
- 90
- 150
- 180
- 210
- 240
- 60
- 180
- 240
- [60, 180, 240]
- [60, 180]'''
- """
- import std/enumerate
- template map[T; Y](i: iterable[T], fn: proc(x: T): Y): untyped =
- iterator internal(): Y {.gensym.} =
- for it in i:
- yield fn(it)
- internal()
- template filter[T](i: iterable[T], fn: proc(x: T): bool): untyped =
- iterator internal(): T {.gensym.} =
- for it in i:
- if fn(it):
- yield it
- internal()
- template group[T](i: iterable[T], amount: static int): untyped =
- iterator internal(): array[amount, T] {.gensym.} =
- var val: array[amount, T]
- for ind, it in enumerate i:
- val[ind mod amount] = it
- if ind mod amount == amount - 1:
- yield val
- internal()
- var a = [10, 20, 30, 50, 60, 70, 80]
- proc mapFn(x: int): int = x * 3
- proc filterFn(x: int): bool = x mod 20 == 0
- for x in a.items.map(mapFn):
- echo x
- for y in a.items.map(mapFn).filter(filterFn):
- echo y
- for y in a.items.map(mapFn).filter(filterFn).group(3):
- echo y
- for y in a.items.map(mapFn).filter(filterFn).group(2):
- echo y
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