string.split(): Draft 1.2

(Issue, Changelog)

This proposal adds string.split() to the sass:string module.

Table of Contents

• Background
• Summary
• Semantics
  • split()

Background

This section is non-normative.

The sass:string module contains several functions for manipulating and finding out information about strings. Currently, though, there is no built-in function that splits one string into a list of substrings, and authors have been creating their own versions of functions that achieve this functionality.

Summary

This section is non-normative.

This proposal adds the string.split() function to the sass:string module. The function takes a string, splits it based on a provided separator, and returns a bracketed, comma-separated list of substrings.

This could be used to take a string and repurpose parts of it for some other use. For example, fonts contained in a font stack list could be split into segments and then used as keys in a new map.

Examples:

$fonts: "Helvetica Neue, Helvetica, Arial";
string.split($fonts, ', '); // ["Helvetica Neue", "Helvetica", "Arial"]

A third argument can set a limit to the the number of splits performed on the string:

string.split($fonts, ', ', 1); // ["Helvetica Neue", "Helvetica, Arial"]

An empty $separator returns all Unicode code points in the original string:

$font: "Helvetica"
string.split($font, ''); // ["H", "e", "l", "v", "e", "t", "i", "c", "a"]

Semantics

split()

split($string, $separator, $limit: null)

• If $string is not a string, throw an error.

• If $separator is not a string, throw an error.

• If $limit is a value other than an integer or null, throw an error.

• If $limit is less than 1, throw an error.

• If $string is an empty string, return a list with $string as the only item.

• Let split-list be an empty list.

• If $limit is null, set $limit to the value of calling string.length($string).

• Let split-counter equal 0.

• While split-counter <= $limit and string.length($string) > 0:

  • If split-counter == $limit:

    • Append $string to split-list.

    • Set $string to an empty string.

  • Otherwise:

    • If $separator is an empty string:

      • Let code-point be the value of calling string.slice($string, 1, 1).

      • Append code-point to split-list.

      • Set $string to string.slice($string, 2).

      • Increase split-counter by 1.

    • Otherwise:

      • Let index be the result of calling string.index($string, $separator).

      • If index is null, append $string to split-list and set $string to an empty string.

      • Otherwise:

        • Let current-substring be the result of calling string.slice($string, 1, index - 1).

        • Append current-substring to split-list.

        • Set $string to string.slice($string, index + string.length($separator)).

        • Increase split-counter by 1.

• Return split-list as a bracketed, comma-separated list.