Strings: added after(), before() and pos() (thanks @icaine) [Closes #20]

src/Utils/Strings.php

@@ -430,6 +430,71 @@ public static function random($length = 10, $charlist = '0-9a-z')
 	}
 
 
+	/**
+	 * Returns part of $haystack before $nth occurence of $needle.
+	 * @param  string
+	 * @param  string
+	 * @param  int  negative value means searching from the end
+	 * @return string|FALSE  returns FALSE if the needle was not found
+	 */
+	public static function before($haystack, $needle, $nth = 1)
+	{
+		$pos = self::pos($haystack, $needle, $nth);
+		return $pos === FALSE
+			? FALSE
+			: substr($haystack, 0, $pos);
+	}
+
+
+	/**
+	 * Returns part of $haystack after $nth occurence of $needle.
+	 * @param  string
+	 * @param  string
+	 * @param  int  negative value means searching from the end
+	 * @return string|FALSE  returns FALSE if the needle was not found
+	 */
+	public static function after($haystack, $needle, $nth = 1)
+	{
+		$pos = self::pos($haystack, $needle, $nth);
+		return $pos === FALSE
+			? FALSE
+			: (string) substr($haystack, $pos + strlen($needle));
+	}
+
+
+	/**
+	 * Returns position of $nth occurence of $needle in $haystack.
+	 * @param  string
+	 * @param  string
+	 * @param  int  negative value means searching from the end
+	 * @return string|FALSE  returns FALSE if the needle was not found
+	 */
+	public static function pos($haystack, $needle, $nth = 1)
+	{
+		if (!$nth) {
+			return FALSE;
+		} elseif ($nth > 0) {
+			if (strlen($needle) === 0) {
+				return 0;
+			}
+			$pos = 0;
+			while (FALSE !== ($pos = strpos($haystack, $needle, $pos)) && --$nth) {
+				$pos++;
+			}
+		} else {
+			$len = strlen($haystack);
+			if (strlen($needle) === 0) {
+				return $len;
+			}
+			$pos = $len - 1;
+			while (FALSE !== ($pos = strrpos($haystack, $needle, $pos - $len)) && ++$nth) {
+				$pos--;
+			}
+		}
+		return $pos;
+	}
+
+
 	/**
 	 * Splits string by a regular expression.
 	 * @param  string

tests/Utils/Strings.after().phpt

@@ -0,0 +1,33 @@
+<?php
+
+/**
+ * Test: Nette\Utils\Strings::after()
+ */
+
+use Nette\Utils\Strings,
+	Tester\Assert;
+
+
+require __DIR__ . '/../bootstrap.php';
+
+
+
+test(function () { //after
+	$foo = '0123456789a123456789b123456789c';
+	Assert::same('123456789a123456789b123456789c', Strings::after($foo, '0', 1));
+	Assert::same('a123456789b123456789c', Strings::after($foo, '9', 1));
+	Assert::same('a123456789b123456789c', Strings::after($foo, '789', 1));
+	Assert::same('0123456789a123456789b123456789c', Strings::after($foo, '', 1));
+	Assert::same('', Strings::after($foo, '', -1));
+	Assert::same('', Strings::after($foo, 'c', -1));
+	Assert::same('c', Strings::after($foo, '9', -1));
+	Assert::same('c', Strings::after($foo, '789', -1));
+	Assert::same('c', Strings::after($foo, '9', 3));
+	Assert::same('c', Strings::after($foo, '789', 3));
+	Assert::same('a123456789b123456789c', Strings::after($foo, '9', -3));
+	Assert::same('a123456789b123456789c', Strings::after($foo, '789', -3));
+	Assert::false(Strings::after($foo, '9', 0));
+	Assert::false(Strings::after($foo, 'not-in-string'));
+	Assert::false(Strings::after($foo, 'b', -2));
+	Assert::false(Strings::after($foo, 'b', 2));
+});

tests/Utils/Strings.before().phpt

@@ -0,0 +1,32 @@
+<?php
+
+/**
+ * Test: Nette\Utils\Strings::before()
+ */
+
+use Nette\Utils\Strings,
+	Tester\Assert;
+
+
+require __DIR__ . '/../bootstrap.php';
+
+
+
+test(function () { //before
+	$foo = '0123456789a123456789b123456789c';
+	Assert::same('', Strings::before($foo, '0', 1));
+	Assert::same('012345678', Strings::before($foo, '9', 1));
+	Assert::same('0123456', Strings::before($foo, '789', 1));
+	Assert::same('', Strings::before($foo, '', 1));
+	Assert::same('0123456789a123456789b123456789c', Strings::before($foo, '', -1));
+	Assert::same('0123456789a123456789b123456789', Strings::before($foo, 'c', -1));
+	Assert::same('0123456789a123456789b123456', Strings::before($foo, '789', -1));
+	Assert::same('0123456789a123456789b12345678', Strings::before($foo, '9', 3));
+	Assert::same('0123456789a123456789b123456', Strings::before($foo, '789', 3));
+	Assert::same('012345678', Strings::before($foo, '9', -3));
+	Assert::same('0123456', Strings::before($foo, '789', -3));
+	Assert::false(Strings::before($foo, '9', 0));
+	Assert::false(Strings::before($foo, 'not-in-string'));
+	Assert::false(Strings::before($foo, 'b', -2));
+	Assert::false(Strings::before($foo, 'b', 2));
+});

tests/Utils/Strings.pos().phpt

@@ -0,0 +1,33 @@
+<?php
+
+/**
+ * Test: Nette\Utils\Strings::pos()
+ */
+
+use Nette\Utils\Strings,
+	Tester\Assert;
+
+
+require __DIR__ . '/../bootstrap.php';
+
+
+
+test(function () { //after
+	$foo = '0123456789a123456789b123456789c';
+	Assert::same(0, Strings::pos($foo, '0', 1));
+	Assert::same(9, Strings::pos($foo, '9', 1));
+	Assert::same(7, Strings::pos($foo, '789', 1));
+	Assert::same(0, Strings::pos($foo, '', 1));
+	Assert::same(31, Strings::pos($foo, '', -1));
+	Assert::same(30, Strings::pos($foo, 'c', -1));
+	Assert::same(29, Strings::pos($foo, '9', -1));
+	Assert::same(27, Strings::pos($foo, '789', -1));
+	Assert::same(29, Strings::pos($foo, '9', 3));
+	Assert::same(27, Strings::pos($foo, '789', 3));
+	Assert::same(9, Strings::pos($foo, '9', -3));
+	Assert::same(7, Strings::pos($foo, '789', -3));
+	Assert::false(Strings::pos($foo, '9', 0));
+	Assert::false(Strings::pos($foo, 'not-in-string'));
+	Assert::false(Strings::pos($foo, 'b', -2));
+	Assert::false(Strings::pos($foo, 'b', 2));
+});