Ranges

Introduction

This article discusses ranges in Ela.

Overview

Ranges in Ela are arithmetic sequences that can be used to generate lists. You only have to specify a first element, a last element, and (optionally) a second element that will be used to calculate stepping.

Strict Ranges

Ranges are created using special literal syntax:

"[" first[,step]..[last] "]"

Here is an example of a simple range:

[1..10]

You can specify an optional step in a range:

[1,3..10]

If the first element of a range is lesser than the last element of a range, a step is mandatory:

[10,9..1]

Non-strict Ranges

It is possible to construct non-strict ranges (such as infinite lists). In this case the last element in range should be omitted:

[1..]
[1,8..]
[100,98..]