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