More bugfixes & optimisations, but I'm still not sure what's up with the correction system

modules/feature-search-didyoumean.php

@@ -348,18 +348,22 @@ class BkTree {
 	 * @return	array<string>			Similar resultant strings from the BK-Tree.
 	 */
 	public function lookup(string $string, int $max_distance = 1, int $count = 0) : array {
+		error_log("[BkTree/lookup]".var_export($string, true).", dist ".var_export($max_distance, true).", count:".var_export($count, true));
 		if($this->get_node_count() == 0) return null;
 		
 		$result = []; $result_count = 0;
 		$stack = [ $this->box->get("node|0") ];
 		$stack_top = 0;
 		
+		$nodes = 0;
+		
 		// https://softwareengineering.stackexchange.com/a/226162/58491
 		while($stack_top >= 0) {
 			// Take the topmost node off the stack
 			$node_current = $stack[$stack_top];
 			unset($stack[$stack_top]);
 			$stack_top--;
+			$nodes++;
 			
 			$distance = levenshtein($string, $node_current->value, $this->cost_insert, $this->cost_replace, $this->cost_delete);
 			
@@ -379,6 +383,8 @@ class BkTree {
 			}
 		}
 		
+		error_log("Nodes traversed: $nodes\n");
+		
 		return $result;
 	}
 	

modules/feature-search.php

@@ -308,7 +308,8 @@ register_module([
 			search::invindex_load($paths->searchindex);
 			$env->perfdata->searchindex_decode_time = (microtime(true) - $env->perfdata->searchindex_decode_start) * 1000;
 			$env->perfdata->searchindex_query_start = microtime(true);
-			$searchResults = search::invindex_query($_GET["query"]);
+			$query_stas = null;
+			$searchResults = search::invindex_query($_GET["query"], $query_stas);
 			$env->perfdata->searchindex_query_time = (microtime(true) - $env->perfdata->searchindex_query_start) * 1000;
 			
 			header("content-type: application/json");
@@ -319,7 +320,8 @@ register_module([
 			if(isset($env->perfdata->didyoumean_correction))
 				$result->didyoumean_correction_time = $env->perfdata->didyoumean_correction;
 			$result->total_time = $result->decode_time + $result->query_time;
-			$result->stas = search::stas_parse(search::stas_split($_GET["query"]));
+			// $result->stas = search::stas_parse(search::stas_split($_GET["query"]));
+			$result->stas = $query_stas;
 			$result->search_results = $searchResults;
 			exit(json_encode($result, JSON_PRETTY_PRINT));
 		});

modules/lib-search-engine.php

@@ -171,7 +171,6 @@ class search
 	 */
 	public static function didyoumean_correct(string $term) : ?string {
 		global $settings, $paths, $env;
-		
 		$start_time = microtime(true);
 		
 		// Load the didyoumean index, but only if it's enabled etc
@@ -186,15 +185,16 @@ class search
 			$term,
 			$settings->search_didyoumean_editdistance
 		);
-		if(empty($results)) return null;
-		usort($results, function($a, $b) : int {
-			return self::compare($a, $b);
-		});
+		if(!empty($results)) {
+			usort($results, function($a, $b) : int {
+				return self::compare($a, $b);
+			});
+		}
 		
 		if(!isset($env->perfdata->didyoumean_correction))
 			$env->perfdata->didyoumean_correction = 0; 
 		$env->perfdata->didyoumean_correction += (microtime(true) - $start_time) * 1000;
-		return $results[0];
+		return $results[0] ?? null;
 	}
 	
 	public static function didyoumean_rebuild(bool $output = true) : void {
@@ -674,6 +674,7 @@ class search
 		if(module_exists("feature-search-didyoumean") && $settings->search_didyoumean_enabled) {
 			$terms_count = count($result["terms"]);
 			for($i = 0; $i < $terms_count; $i++) {
+				error_log("[stas_parse/didyoumean] Now looking at #$i:  ".var_export($result["terms"][$i], true)."(total count: $terms_count)");
 				if($result["terms"][$i]["exact"] || // Skip exact-only
 					$result["terms"][$i]["weight"] < 1 || // Skip stop & irrelevant words
 					self::invindex_term_exists($result["terms"][$i]["term"])) continue;
@@ -712,10 +713,14 @@ class search
 	
 	/**
 	 * Searches the given inverted index for the specified search terms.
-	 * @param	string	$query		The search query.
+	 * Note that this automatically pushes the query string through STAS which
+	 * can  be a fairly expensive operation, so use 2nd argument if you need
+	 * to debug the STAS parsing result if possible.
+	 * @param	string		$query		The search query.
+	 * @param	&stdClass	$query_stas	An object to fill with the result of the STAS parsing.
 	 * @return	array	An array of matching pages.
 	 */
-	public static function invindex_query($query)
+	public static function invindex_query($query, &$query_stas = null)
 	{
 		global $settings, $pageindex;