Version 4.7.23

2025-12-19 16:21:27 -08:00
1 parent 7124a02564
commit 25ddeb65d6
@@ -0,0 +1,128 @@
+<?php
+
+namespace Garfix\JsMinify;
+
+/**
+ * @author Patrick van Bergen
+ */
+class MinifierExpressions
+{
+	protected static $expressions = null;
+
+	public $tokenExpressions = [];
+	public $allExpressions = [];
+	public $safeNewlines = [];
+	public $whitespaceArrayPlaceholders = [];
+	public $whitespaceArrayNewline;
+	public $whitespaceCharsNewline;
+	public $optionalWhitespaceNewline;
+	public $someWhitespace;
+	public $regexp;
+
+	/**
+	 * @return MinifierExpressions
+	 */
+	public static function get() {
+		if (self::$expressions === null) {
+			self::$expressions = self::create();
+		}
+		return self::$expressions;
+	}
+
+	protected static function create() {
+
+		$e = new MinifierExpressions();
+
+		// white space (includes space and tab) https://262.ecma-international.org/6.0/#sec-white-space
+		$whitespaceArray = [" ", "\t"];
+		$e->whitespaceArrayNewline = array_merge($whitespaceArray, ["\n"]);
+		// placeholders are unused code points; see also https://en.wikipedia.org/wiki/Private_Use_Areas
+		$e->whitespaceArrayPlaceholders = ["\x{E000}", "\x{E001}", "\x{E002}"];
+
+		$whitespaceChars = implode("", $whitespaceArray);
+		$e->whitespaceCharsNewline = "\n" . $whitespaceChars;
+
+		$whitespace = "[" . $whitespaceChars . "]";
+		$whitespaceNewline = "[" . $e->whitespaceCharsNewline . "]";
+
+		// possessive quantifier (++) is needed when used in combination with look ahead
+		$e->someWhitespace = $whitespace . "++";
+		$someWhitespaceNewline = $whitespaceNewline . "++";
+		$optionalWhitespace = $whitespace . "*+";
+		$e->optionalWhitespaceNewline = $whitespaceNewline . "*+";
+
+		// a single escaped character in a regexp, like \\ or \n (may not be newline)
+		$regexEscape = "\\\\[^\n]";
+		// regexp character class: [..] with escape characters
+		// [^\n\\]] is any non-] character (also not be newline)
+		$characterClass = "\\[(?:" . $regexEscape . "|[^\n\\]])*+\\]";
+		// regexp: /..(..)../i with character class and escaped characters
+		// [^\n/] is any non-slash character (also not be newline)
+		$e->regexp = "/(?:" . $regexEscape . "|" . $characterClass . "|[^\n/])++/[igmus]*+";
+
+		// characters than can form a word; these characters should not be joined together by the removal of whitespace
+		$word = "[a-zA-Z0-9_\$\x{0080}-\x{FFFF}]";
+
+		// note: ! is not infix and not safe
+		$safeOperators = ",\.&|*/%=<>?:";
+		$openingBrackets = "({[";
+		$closingBrackets = ")}\\]";
+		$expressionClosingBracket = ")";
+		$blockOpeningBracket = "{";
+
+		// newlines that may be safely removed
+		$e->safeNewlines = [
+			// newline preceded by opening bracket or operator
+			"(?<=[;" . $openingBrackets . $safeOperators . "])" . "\n",
+			// newline followed by closing bracket or operator
+			"\n" . "(?=[;" . $closingBrackets. $safeOperators . "])",
+			// ( \n [
+			"(?<=[" . $openingBrackets . "])" . "\n" . "(?=[" . $openingBrackets . "])",
+			// ] \n )
+			"(?<=[" . $closingBrackets . "])" . "\n" . "(?=[" . $closingBrackets . "])",
+			// } \n (
+			"(?<=[" . $expressionClosingBracket . "])" . "\n" . "(?=[" . $blockOpeningBracket . "])",
+		];
+
+		// these expression must always be present, because they keep tokens that contain whitespace together
+		$e->tokenExpressions = [
+			// /** comment */
+			'starComment' => "(?<starComment>" . "/\*.*?\*/" . $e->optionalWhitespaceNewline . ")",
+			// // comment
+			'lineComment' => "(?<lineComment>//[^\n]*" . $e->optionalWhitespaceNewline . ")",
+			// regular expression
+			'regexp' =>
+				"(?<regexp>" .
+				// if there's whitespace, match it all
+				$e->regexp . $optionalWhitespace .
+				// to distinguish a regexp from a sequence of dividers (i.e.: x / y / z):
+				"(?:" .
+				// it is followed by a newline; add it to the match
+				"\n" .
+				"|" .
+				// it is followed by any of these characters
+				"(?=[;,\.)])" .
+				")" .
+				")",
+			// "double quotes"
+			'double' => '(?<doubleQuote>"(?:\\\\.|[^"])*+")',
+			// 'single quotes'
+			'single' => "(?<singleQuote>'(?:\\\\.|[^'])*+')",
+			// `template literal`
+			'template' => "(?<templateLiteral>`(?:\\\\.|[^`])*+`)",
+		];
+
+		$specificExpressions = [
+			// a sequence of - and -- operators; i.e. a - --b; b-- -c; d-- - -e; f - -g
+			'min' => "(?<=-)(?<min>" . $someWhitespaceNewline . ")(?=-)",
+			// a sequence of + and ++ operators
+			'plus' => "(?<=\+)(?<plus>" . $someWhitespaceNewline . ")(?=\+)",
+			// whitespace both preceded and succeeded by a word char
+			'requiredSpace' => "(?<=" . $word . ")" . "(?<requiredSpace>" . $someWhitespaceNewline . ")" . "(?=" . $word . ")"
+		];
+
+		$e->allExpressions = array_merge($e->tokenExpressions, $specificExpressions);
+
+		return $e;
+	}
+}