Helpers::getSuggestion() better balance. Replacement is more expensive than insertion/deletion.

src/Dibi/Helpers.php

@@ -141,10 +141,10 @@ class Helpers
 	public static function getSuggestion(array $items, $value)
 	{
 		$best = NULL;
-		$min = (int) (strlen($value) / 4) + 2;
-		foreach ($items as $item) {
+		$min = (strlen($value) / 4 + 1) * 10 + .1;
+		foreach (array_unique($items, SORT_REGULAR) as $item) {
 			$item = is_object($item) ? $item->getName() : $item;
-			if (($len = levenshtein($item, $value)) > 0 && $len < $min) {
+			if (($len = levenshtein($item, $value, 10, 11, 10)) > 0 && $len < $min) {
 				$min = $len;
 				$best = $item;
 			}

tests/dibi/Helpers.getSuggestion().phpt

@@ -0,0 +1,36 @@
+<?php
+
+use Dibi\Helpers;
+use Tester\Assert;
+
+require __DIR__ . '/bootstrap.php';
+
+
+Assert::same(NULL, Helpers::getSuggestion([], ''));
+Assert::same(NULL, Helpers::getSuggestion([], 'a'));
+Assert::same(NULL, Helpers::getSuggestion(['a'], 'a'));
+Assert::same('a', Helpers::getSuggestion(['a', 'b'], ''));
+Assert::same('b', Helpers::getSuggestion(['a', 'b'], 'a')); // ignore 100% match
+Assert::same('a1', Helpers::getSuggestion(['a1', 'a2'], 'a')); // take first
+Assert::same(NULL, Helpers::getSuggestion(['aaa', 'bbb'], 'a'));
+Assert::same(NULL, Helpers::getSuggestion(['aaa', 'bbb'], 'ab'));
+Assert::same(NULL, Helpers::getSuggestion(['aaa', 'bbb'], 'abc'));
+Assert::same('bar', Helpers::getSuggestion(['foo', 'bar', 'baz'], 'baz'));
+Assert::same('abcd', Helpers::getSuggestion(['abcd'], 'acbd'));
+Assert::same('abcd', Helpers::getSuggestion(['abcd'], 'axbd'));
+Assert::same(NULL, Helpers::getSuggestion(['abcd'], 'axyd'));
+
+
+/*
+length  allowed ins/del  replacements
+-------------------------------------
+0       1                0
+1       1                1
+2       1                1
+3       1                1
+4       2                1
+5       2                2
+6       2                2
+7       2                2
+8       3                2
+*/