Iterator Tools

This module provides two different ways of managing combinatorics. Let see an example for combinations.

Fully formed array of all Combinations

// combinations will return an array of all length `r` combinations of `data`
// While waiting on https://github.com/vlang/v/issues/7753 to be fixed, the function
// assumes f64 array input. Will be easy to change to generic later
pub fn combinations(data []f64, r int) [][]f64

Usage example

module main

import vsl.iter

data := [1.0, 2.0, 3.0]
r := 3
combs := iter.combinations(data, r)
print(combs)

Lazy generation

This case is optimal to generate combinations in a lazy way, optimizing memory use:

// new_combinations_iter will return an iterator that allows
// lazy computation for all length `r` combinations of `data`
pub fn new_combinations_iter(data []f64, r int) CombinationsIter

// next will return next combination if possible
pub fn (mut o CombinationsIter) next() ?[]f64

Lazy generation usage example

module main

import vsl.iter

data := [1.0, 2.0, 3.0]
r := 3
mut combs := iter.new_combinations_iter(data, r)
for comb in combs {
	print(comb)
}