Pepperminty-Wiki/modules/feature-search.php

<?php
register_module([
	"name" => "Search",
	"version" => "0.1",
	"author" => "Starbeamrainbowlabs",
	"description" => "Adds proper search functionality to Pepperminty Wiki. Note that this module, at the moment, just contains test code while I figure out how best to write a search engine.",
	"id" => "feature-search",
	"code" => function() {
		add_action("index", function() {
			global $settings, $env;
			
			$breakable_chars = "\r\n\t .,\\/!\"£$%^&*[]()+`_~#";
			
			header("content-type: text/plain");
			
			$source = file_get_contents("$env->page.md");
			
			$index = search::index($source);
			
			var_dump($env->page);
			var_dump($source);
			
			var_dump($index);
		});
	}
]);

class search
{
	public static $stop_words = [
		"a", "about", "above", "above", "across", "after", "afterwards", "again", "against",
		"all", "almost", "alone", "along", "already", "also", "although", "always", "am", "among",
		"amongst", "amoungst", "amount",  "an", "and", "another", "any", "anyhow", "anyone", "anything",
		"anyway", "anywhere", "are", "around", "as",  "at", "back", "be", "became", "because", "become",
		"becomes", "becoming", "been", "before", "beforehand", "behind", "being", "below", "beside",
		"besides", "between", "beyond", "bill", "both", "bottom", "but", "by", "call", "can", "cannot",
		"cant", "co", "con", "could", "couldnt", "cry", "de", "describe", "detail", "do", "done", "down",
		"due", "during", "each", "eg", "eight", "either", "eleven", "else", "elsewhere", "empty",
		"enough", "etc", "even", "ever", "every", "everyone", "everything", "everywhere", "except",
		"few", "fifteen", "fify", "fill", "find", "fire", "first", "five", "for", "former", "formerly",
		"forty", "found", "four", "from", "front", "full", "further", "get", "give", "go", "had", "has",
		"hasnt", "have", "he", "hence", "her", "here", "hereafter", "hereby", "herein", "hereupon",
		"hers", "herself", "him", "himself", "his", "how", "however", "hundred", "ie", "if", "in",
		"inc", "indeed", "interest", "into", "is", "it", "its", "itself", "keep", "last", "latter",
		"latterly", "least", "less", "ltd", "made", "many", "may", "me", "meanwhile", "might", "mill",
		"mine", "more", "moreover", "most", "mostly", "move", "much", "must", "my", "myself", "name",
		"namely", "neither", "never", "nevertheless", "next", "nine", "no", "nobody", "none", "noone",
		"nor", "not", "nothing", "now", "nowhere", "of", "off", "often", "on", "once", "one", "only",
		"onto", "or", "other", "others", "otherwise", "our", "ours", "ourselves", "out", "over", "own",
		"part", "per", "perhaps", "please", "put", "rather", "re", "same", "see", "seem", "seemed",
		"seeming", "seems", "serious", "several", "she", "should", "show", "side", "since", "sincere",
		"six", "sixty", "so", "some", "somehow", "someone", "something", "sometime", "sometimes",
		"somewhere", "still", "such", "system", "take", "ten", "than", "that", "the", "their", "them",
		"themselves", "then", "thence", "there", "thereafter", "thereby", "therefore", "therein",
		"thereupon", "these", "they", "thickv", "thin", "third", "this", "those", "though", "three",
		"through", "throughout", "thru", "thus", "to", "together", "too", "top", "toward", "towards",
		"twelve", "twenty", "two", "un", "under", "until", "up", "upon", "us", "very", "via", "was",
		"we", "well", "were", "what", "whatever", "when", "whence", "whenever", "where", "whereafter",
		"whereas", "whereby", "wherein", "whereupon", "wherever", "whether", "which", "while", "whither",
		"who", "whoever", "whole", "whom", "whose", "why", "will", "with", "within", "without", "would",
		"yet", "you", "your", "yours", "yourself", "yourselves"
	];

	public static function index($source)
	{
		$source = html_entity_decode($source, ENT_QUOTES);
		$source_length = strlen($source);
			
		$index = [];

		// Regex from 
		$terms = preg_split("/((^\p{P}+)|(\p{P}*\s+\p{P}*)|(\p{P}+$))/", $source, -1, PREG_SPLIT_NO_EMPTY);
		$i = 0;
		foreach($terms as $term)
		{
			$nterm = strtolower($term);
			
			// Skip over stop words (see https://en.wikipedia.org/wiki/Stop_words)
			if(in_array($nterm, self::$stop_words)) continue;
			
			if(!isset($index[$nterm]))
			{
				$index[$nterm] = [ "freq" => 0, "offsets" => [] ];
			}
			
			$index[$nterm]["freq"]++;
			$index[$nterm]["offsets"][] = $i;
			
			$i++;
		}
		
		self::sort_index($index);
		
		return $index;
	}
	
	/*
	 * @sumary Sorts an index alphabetically. This allows us to do a binary search instead of a regular sequential search.
	 */
	public static function sort_index(&$index)
	{
		ksort($index, SORT_NATURAL);
	}
}

class ids
{
	/*
	 * @summary Gets the page id associated with the given pagename.
	 */
	public static function get_page_id($pagename)
	{
		global $idindex;
		
		
	}
	
	/*
	 * @summary Gets the page name associated with the given page id.
	 */
	public static function get_id_pagename($id)
	{
		global $idindex;
		
		
	}
}

?>