Std\Range

Integer ranges with optional step — lazy representation, materialized on demand.

Ranges are represented as (:range, start, stop, step) tuples. They don’t allocate a sequence until toList is called.

Functions

Creates a range from start to stop (inclusive) with step 1.

toList (range 1 5)   # => [1, 2, 3, 4, 5]

Creates a range from start to stop with a custom step.

toList (rangeStep 0 10 3)   # => [0, 3, 6, 9]
toList (rangeStep 10 0 (0 - 2))   # => [10, 8, 6, 4, 2, 0]

Materializes the range into a sequence.

toList (range 1 3)   # => [1, 2, 3]

Returns true if value falls within the range and aligns with the step.

contains 3 (range 1 5)         # => true
contains 3 (rangeStep 0 10 2)  # => false  (0, 2, 4, 6, 8, 10)

Returns the number of elements in the range.

length (range 1 10)   # => 10

Returns a range containing only the first n elements.

toList (take 3 (range 1 10))   # => [1, 2, 3]

Returns a range with the first n elements removed.

toList (drop 3 (range 1 5))   # => [4, 5]

Applies fn to each element, returning a sequence (not a range).

map (\x -> x * x) (range 1 4)   # => [1, 4, 9, 16]

Keeps only elements satisfying pred, returning a sequence.

filter (\x -> x % 2 == 0) (range 1 6)   # => [2, 4, 6]

Left fold over the range.

fold (\acc x -> acc + x) 0 (range 1 5)   # => 15

Applies fn to each element for side effects.

forEach (\x -> print x) (range 1 3)   # prints 1, 2, 3