SliceableStringy

Python string slices in PHP. The class extends Stringy, and implements the ArrayAccess interface.

• Installation
• Overview
• Examples
• Implementation Fidelity
• TL;DR

Installation

If you're using Composer to manage dependencies, you can include the following in your composer.json file:

"require": {
    "danielstjules/sliceable-stringy": "dev-master"
}

Then, after running composer update or php composer.phar update, you can load the class using Composer's autoloader:

require 'vendor/autoload.php';

Overview

SliceableStringy returns a slice when passed a string offset containing one or more colons. Up to 3 arguments may be passed: 'start:stop:step'. Start, which indicates the starting index of the slice, defaults to the first character in the string if step is positive, and the last character if negative. Stop, which indicates the exclusive boundary of the range, defaults to the length of the string if step is positive, and before the first character if negative. And step allows the user to include only every nth character in the result, with its sign determining the direction in which indices are sampled.

Just like Stringy, SliceableStringy is immutable and returns a new instance with each slice.

Examples

use SliceableStringy\SliceableStringy as S;

$sliceable = S::create('Fòô Bàř', 'UTF-8');

Specific offset

$sliceable[1];    // 'ò'
$sliceable['-2']; // 'à'

Using start and stop

$sliceable[':'];   // 'Fòô Bàř'
$sliceable['4:'];  // 'Bàř'
$sliceable['4:6']; // 'Bà'

Negative indices

$sliceable['-1:'];  // 'ř'
$sliceable[':-1'];  // 'Fòô Bà'
$sliceable['-3:6']; // 'Bà'
$sliceable['2:-6']; // ''

Passing a step

$sliceable['::-1'];   // 'řàB ôòF'
$sliceable['::2'];    // 'FôBř'
$sliceable['-3::-2']; // 'BôF'

Possible exceptions

$sliceable[20];        // OutOfBoundsException
$sliceable['1:2:3:4']; // InvalidArgumentException, too many slice args
$sliceable['::0'];     // InvalidArgumentException, step cannot equal 0

Implementation Fidelity

A number of specs in spec/SliceableStringySpec.php assert that the library mimics Python's native slice notation. On top of the handful of unit tests, spec/fixtures/resultGenerator.py has been used to generate test fixtures. Each of the slices in expectedResults.csv are checked against SliceableStringy to ensure correct functionality.

TL;DR

Butchering two languages with a single library.