range

Numeric ranges in V.

Why

• a..b in V can only be in increasing order and not in negative order.
• Lacks inbuilt step which most people need or want.
• No support for float type.
• Solution for vlang/v#5944.

Features

• Make range easily
• Make ranges for int and f32
• Positive as well as negative support!
• No need to write the whole for loop! (this maybe slower than the normal one)
• Use range for functional programming
• Support iterators. Long ranges without high memory allocation.
• Half open-open ranges [from,to]

Installation

• Via git clone
  • git clone https://github.com/Delta456/range
• Via v install
  • v install Delta456.range
• Via vpkg
  • vpkg install range

Usage

Use an iterator if you need a large range but don't want to allocate space in memory for all numbers in the range.

import delta456.range

mut iter := range.to_iterator(from: 0, to: 1000000, step: 2)
for v in iter {
  println(v)
}

$ v run main.v
0
2
4

Use an array when you need it and the memory allocation for all values in the range is not a problem.

import delta456.range

arr := range.to_array(from: 10, to: 0, step: -1)
println(arr)

v run main.v
[10, 9, 8, 7, 6, 5, 4, 3, 2, 1]

If you prefer you can use the builder syntax.

mut iter := range.new[int]().from(0).to(10).step(1).to_iterator()

// or

arr := range.new[int]().from(0).to(10).step(1).to_array()

// or

mut iter := range.Builder[int]{ from: 0, to: 10, step: 1 }.to_iterator()

// or

arr := range.Builder[int]{ from: 0, to: 10, step: 1 }.to_array()

The builder is immutable! You can reuse it as many times as you want.

zero_to_nine := range.new[int]().from(0).to(10).step(1)

// print from 0 to 9
for v in zero_to_nine.to_iterator() {
  println(v)
}

// print from 0 to 9 again, no problems
for v in zero_to_nine.to_iterator() {
  println(v)
}

License

Released under MIT