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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
|
