%PDF-
%PDF-
Mini Shell
Mini Shell
<?php
/**
* JavaScript Minifier
*
* @file
* @author Paul Copperman <paul.copperman@gmail.com>
* @license Apache-2.0
* @license MIT
* @license GPL-2.0-or-later
* @license LGPL-2.1-or-later
*/
/**
* This class is meant to safely minify javascript code, while leaving syntactically correct
* programs intact. Other libraries, such as JSMin require a certain coding style to work
* correctly. OTOH, libraries like jsminplus, that do parse the code correctly are rather
* slow, because they construct a complete parse tree before outputting the code minified.
* So this class is meant to allow arbitrary (but syntactically correct) input, while being
* fast enough to be used for on-the-fly minifying.
*
* This class was written with ECMA-262 Edition 3 in mind ("ECMAScript 3"). Parsing features
* new to ECMAScript 5 or later might not be supported. However, Edition 5.1 better reflects
* how actual JS engines worked and work and is simpler and more readable prose. As such,
* the below code will refer to sections of the 5.1 specification.
*
* See <https://www.ecma-international.org/ecma-262/5.1/>.
*/
class JavaScriptMinifier {
/* Parsing states.
* The state machine is only necessary to decide whether to parse a slash as division
* operator or as regexp literal.
* States are named after the next expected item. We only distinguish states when the
* distinction is relevant for our purpose.
*/
const STATEMENT = 0;
const CONDITION = 1;
const PROPERTY_ASSIGNMENT = 2;
const EXPRESSION = 3;
const EXPRESSION_NO_NL = 4; // only relevant for semicolon insertion
const EXPRESSION_OP = 5;
const EXPRESSION_FUNC = 6;
const EXPRESSION_TERNARY = 7; // used to determine the role of a colon
const EXPRESSION_TERNARY_OP = 8;
const EXPRESSION_TERNARY_FUNC = 9;
const PAREN_EXPRESSION = 10; // expression which is not on the top level
const PAREN_EXPRESSION_OP = 11;
const PAREN_EXPRESSION_FUNC = 12;
const PROPERTY_EXPRESSION = 13; // expression which is within an object literal
const PROPERTY_EXPRESSION_OP = 14;
const PROPERTY_EXPRESSION_FUNC = 15;
/* Token types */
const TYPE_UN_OP = 101; // unary operators
const TYPE_INCR_OP = 102; // ++ and --
const TYPE_BIN_OP = 103; // binary operators
const TYPE_ADD_OP = 104; // + and - which can be either unary or binary ops
const TYPE_HOOK = 105; // ?
const TYPE_COLON = 106; // :
const TYPE_COMMA = 107; // ,
const TYPE_SEMICOLON = 108; // ;
const TYPE_BRACE_OPEN = 109; // {
const TYPE_BRACE_CLOSE = 110; // }
const TYPE_PAREN_OPEN = 111; // ( and [
const TYPE_PAREN_CLOSE = 112; // ) and ]
const TYPE_RETURN = 113; // keywords: break, continue, return, throw
const TYPE_IF = 114; // keywords: catch, for, with, switch, while, if
const TYPE_DO = 115; // keywords: case, var, finally, else, do, try
const TYPE_FUNC = 116; // keywords: function
const TYPE_LITERAL = 117; // all literals, identifiers and unrecognised tokens
const ACTION_GOTO = 201;
const ACTION_PUSH = 202;
const ACTION_POP = 203;
// Sanity limit to avoid excessive memory usage
const STACK_LIMIT = 1000;
/**
* Maximum line length
*
* This is not a strict maximum, but a guideline. Longer lines will be
* produced when literals (e.g. quoted strings) longer than this are
* encountered, or when required to guard against semicolon insertion.
*
* This is a private member (instead of constant) to allow tests to
* set it to 1, to verify ASI and line-breaking behaviour.
*/
private static $maxLineLength = 1000;
/**
* Returns minified JavaScript code.
*
* @param string $s JavaScript code to minify
* @return String Minified code
*/
public static function minify( $s ) {
// First we declare a few tables that contain our parsing rules
// $opChars : Characters which can be combined without whitespace between them.
$opChars = [
// ECMAScript 5.1 § 7.7 Punctuators
// Unlike the spec, these are individual symbols, not sequences.
'{' => true,
'}' => true,
'(' => true,
')' => true,
'[' => true,
']' => true,
'.' => true,
';' => true,
',' => true,
'<' => true,
'>' => true,
'=' => true,
'!' => true,
'+' => true,
'-' => true,
'*' => true,
'%' => true,
'&' => true,
'|' => true,
'^' => true,
'~' => true,
'?' => true,
':' => true,
'/' => true,
// ECMAScript 5.1 § 7.8.4 String Literals
'"' => true,
"'" => true,
];
// $tokenTypes : Map keywords and operators to their corresponding token type
$tokenTypes = [
// ECMAScript 5.1 § 11.4 Unary Operators
// ECMAScript 5.1 § 11.6 Additive Operators
// UnaryExpression includes PostfixExpression, which includes 'new'.
'new' => self::TYPE_UN_OP,
'delete' => self::TYPE_UN_OP,
'void' => self::TYPE_UN_OP,
'typeof' => self::TYPE_UN_OP,
'++' => self::TYPE_INCR_OP,
'--' => self::TYPE_INCR_OP,
'+' => self::TYPE_ADD_OP,
'-' => self::TYPE_ADD_OP,
'~' => self::TYPE_UN_OP,
'!' => self::TYPE_UN_OP,
// ECMAScript 5.1 § 11.5 Multiplicative Operators
'*' => self::TYPE_BIN_OP,
'/' => self::TYPE_BIN_OP,
'%' => self::TYPE_BIN_OP,
// ECMAScript 5.1 § 11.7 Bitwise Shift Operators
'<<' => self::TYPE_BIN_OP,
'>>' => self::TYPE_BIN_OP,
'>>>' => self::TYPE_BIN_OP,
// ECMAScript 5.1 § 11.8 Relational Operators
'<' => self::TYPE_BIN_OP,
'>' => self::TYPE_BIN_OP,
'<=' => self::TYPE_BIN_OP,
'>=' => self::TYPE_BIN_OP,
// ECMAScript 5.1 § 11.9 Equality Operators
'==' => self::TYPE_BIN_OP,
'!=' => self::TYPE_BIN_OP,
'===' => self::TYPE_BIN_OP,
'!==' => self::TYPE_BIN_OP,
'instanceof' => self::TYPE_BIN_OP,
'in' => self::TYPE_BIN_OP,
// ECMAScript 5.1 § 11.10 Binary Bitwise Operators
'&' => self::TYPE_BIN_OP,
'^' => self::TYPE_BIN_OP,
'|' => self::TYPE_BIN_OP,
// ECMAScript 5.1 § 11.11 Binary Logical Operators
'&&' => self::TYPE_BIN_OP,
'||' => self::TYPE_BIN_OP,
// ECMAScript 5.1 § 11.12 Conditional Operator
// Also known as ternary.
'?' => self::TYPE_HOOK,
':' => self::TYPE_COLON,
// ECMAScript 5.1 § 11.13 Assignment Operators
'=' => self::TYPE_BIN_OP,
'*=' => self::TYPE_BIN_OP,
'/=' => self::TYPE_BIN_OP,
'%=' => self::TYPE_BIN_OP,
'+=' => self::TYPE_BIN_OP,
'-=' => self::TYPE_BIN_OP,
'<<=' => self::TYPE_BIN_OP,
'>>=' => self::TYPE_BIN_OP,
'>>>=' => self::TYPE_BIN_OP,
'&=' => self::TYPE_BIN_OP,
'^=' => self::TYPE_BIN_OP,
'|=' => self::TYPE_BIN_OP,
// ECMAScript 5.1 § 11.14 Comma Operator
',' => self::TYPE_COMMA,
// The keywords that disallow LineTerminator before their
// (sometimes optional) Expression or Identifier.
//
// keyword ;
// keyword [no LineTerminator here] Identifier ;
// keyword [no LineTerminator here] Expression ;
//
// See also ECMAScript 5.1:
// - § 12.7 The continue Statement
// - $ 12.8 The break Statement
// - § 12.9 The return Statement
// - § 12.13 The throw Statement
'continue' => self::TYPE_RETURN,
'break' => self::TYPE_RETURN,
'return' => self::TYPE_RETURN,
'throw' => self::TYPE_RETURN,
// The keywords require a parenthesised Expression or Identifier
// before the next Statement.
//
// keyword ( Expression ) Statement
// keyword ( Identifier ) Statement
//
// See also ECMAScript 5.1:
// - § 12.5 The if Statement
// - § 12.6 Iteration Statements (do, while, for)
// - § 12.10 The with Statement
// - § 12.11 The switch Statement
// - § 12.13 The throw Statement
'if' => self::TYPE_IF,
'catch' => self::TYPE_IF,
'while' => self::TYPE_IF,
'for' => self::TYPE_IF,
'switch' => self::TYPE_IF,
'with' => self::TYPE_IF,
// The keywords followed by an Identifier, Statement,
// Expression, or Block.
//
// var Identifier
// else Statement
// do Statement
// case Expression
// try Block
// finally Block
//
// See also ECMAScript 5.1:
// - § 12.2 Variable Statement
// - § 12.5 The if Statement (else)
// - § 12.6 Iteration Statements (do, while, for)
// - § 12.11 The switch Statement (case)
// - § 12.14 The try Statement
'var' => self::TYPE_DO,
'else' => self::TYPE_DO,
'do' => self::TYPE_DO,
'case' => self::TYPE_DO,
'try' => self::TYPE_DO,
'finally' => self::TYPE_DO,
// ECMAScript 5.1 § 13 Function Definition
'function' => self::TYPE_FUNC,
// Can be one of:
// - DecimalLiteral (ECMAScript 5.1 § 7.8.3 Numeric Literals)
// - MemberExpression (ECMAScript 5.1 § 11.2 Left-Hand-Side Expressions)
'.' => self::TYPE_BIN_OP,
// Can be one of:
// - Block (ECMAScript 5.1 § 12.1 Block)
// - ObjectLiteral (ECMAScript 5.1 § 11.1 Primary Expressions)
'{' => self::TYPE_BRACE_OPEN,
'}' => self::TYPE_BRACE_CLOSE,
// Can be one of:
// - Parenthesised Identifier or Expression after a
// TYPE_IF or TYPE_FUNC keyword.
// - PrimaryExpression (ECMAScript 5.1 § 11.1 Primary Expressions)
// - CallExpression (ECMAScript 5.1 § 11.2 Left-Hand-Side Expressions)
'(' => self::TYPE_PAREN_OPEN,
')' => self::TYPE_PAREN_CLOSE,
// Can be one of:
// - ArrayLiteral (ECMAScript 5.1 § 11.1 Primary Expressions)
'[' => self::TYPE_PAREN_OPEN,
']' => self::TYPE_PAREN_CLOSE,
// Can be one of:
// - End of any statement
// - EmptyStatement (ECMAScript 5.1 § 12.3 Empty Statement)
';' => self::TYPE_SEMICOLON,
];
// $model : This is the main table for our state machine. For every state/token pair
// the desired action is defined.
//
// The state pushed onto the stack by ACTION_PUSH will be returned to by ACTION_POP.
//
// A given state/token pair MAY NOT specify both ACTION_POP and ACTION_GOTO.
// In the event of such mistake, ACTION_POP is used instead of ACTION_GOTO.
$model = [
// Statement - This is the initial state.
self::STATEMENT => [
self::TYPE_UN_OP => [
self::ACTION_GOTO => self::EXPRESSION,
],
self::TYPE_INCR_OP => [
self::ACTION_GOTO => self::EXPRESSION,
],
self::TYPE_ADD_OP => [
self::ACTION_GOTO => self::EXPRESSION,
],
self::TYPE_BRACE_OPEN => [
// Use of '{' in statement context, creates a Block.
self::ACTION_PUSH => self::STATEMENT,
],
self::TYPE_BRACE_CLOSE => [
// Ends a Block
self::ACTION_POP => true,
],
self::TYPE_PAREN_OPEN => [
self::ACTION_PUSH => self::EXPRESSION_OP,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_RETURN => [
self::ACTION_GOTO => self::EXPRESSION_NO_NL,
],
self::TYPE_IF => [
self::ACTION_GOTO => self::CONDITION,
],
self::TYPE_FUNC => [
self::ACTION_GOTO => self::CONDITION,
],
self::TYPE_LITERAL => [
self::ACTION_GOTO => self::EXPRESSION_OP,
],
],
self::CONDITION => [
self::TYPE_PAREN_OPEN => [
self::ACTION_PUSH => self::STATEMENT,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
],
// Property assignment - This is an object literal declaration.
// For example: `{ key: value }`
self::PROPERTY_ASSIGNMENT => [
self::TYPE_COLON => [
self::ACTION_GOTO => self::PROPERTY_EXPRESSION,
],
self::TYPE_BRACE_OPEN => [
self::ACTION_PUSH => self::PROPERTY_ASSIGNMENT,
self::ACTION_GOTO => self::STATEMENT,
],
self::TYPE_BRACE_CLOSE => [
self::ACTION_POP => true,
],
],
self::EXPRESSION => [
self::TYPE_SEMICOLON => [
self::ACTION_GOTO => self::STATEMENT,
],
self::TYPE_BRACE_OPEN => [
self::ACTION_PUSH => self::EXPRESSION_OP,
self::ACTION_GOTO => self::PROPERTY_ASSIGNMENT,
],
self::TYPE_BRACE_CLOSE => [
self::ACTION_POP => true,
],
self::TYPE_PAREN_OPEN => [
self::ACTION_PUSH => self::EXPRESSION_OP,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_FUNC => [
self::ACTION_GOTO => self::EXPRESSION_FUNC,
],
self::TYPE_LITERAL => [
self::ACTION_GOTO => self::EXPRESSION_OP,
],
],
self::EXPRESSION_NO_NL => [
self::TYPE_SEMICOLON => [
self::ACTION_GOTO => self::STATEMENT,
],
self::TYPE_BRACE_OPEN => [
self::ACTION_PUSH => self::EXPRESSION_OP,
self::ACTION_GOTO => self::PROPERTY_ASSIGNMENT,
],
self::TYPE_BRACE_CLOSE => [
self::ACTION_POP => true,
],
self::TYPE_PAREN_OPEN => [
self::ACTION_PUSH => self::EXPRESSION_OP,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_FUNC => [
self::ACTION_GOTO => self::EXPRESSION_FUNC,
],
self::TYPE_LITERAL => [
self::ACTION_GOTO => self::EXPRESSION_OP,
],
],
self::EXPRESSION_OP => [
self::TYPE_BIN_OP => [
self::ACTION_GOTO => self::EXPRESSION,
],
self::TYPE_ADD_OP => [
self::ACTION_GOTO => self::EXPRESSION,
],
self::TYPE_HOOK => [
self::ACTION_PUSH => self::EXPRESSION,
self::ACTION_GOTO => self::EXPRESSION_TERNARY,
],
self::TYPE_COLON => [
self::ACTION_GOTO => self::STATEMENT,
],
self::TYPE_COMMA => [
self::ACTION_GOTO => self::EXPRESSION,
],
self::TYPE_SEMICOLON => [
self::ACTION_GOTO => self::STATEMENT,
],
self::TYPE_PAREN_OPEN => [
self::ACTION_PUSH => self::EXPRESSION_OP,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_BRACE_CLOSE => [
self::ACTION_POP => true,
],
],
self::EXPRESSION_FUNC => [
self::TYPE_BRACE_OPEN => [
self::ACTION_PUSH => self::EXPRESSION_OP,
self::ACTION_GOTO => self::STATEMENT,
],
],
self::EXPRESSION_TERNARY => [
self::TYPE_BRACE_OPEN => [
self::ACTION_PUSH => self::EXPRESSION_TERNARY_OP,
self::ACTION_GOTO => self::PROPERTY_ASSIGNMENT,
],
self::TYPE_PAREN_OPEN => [
self::ACTION_PUSH => self::EXPRESSION_TERNARY_OP,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_FUNC => [
self::ACTION_GOTO => self::EXPRESSION_TERNARY_FUNC,
],
self::TYPE_LITERAL => [
self::ACTION_GOTO => self::EXPRESSION_TERNARY_OP,
],
],
self::EXPRESSION_TERNARY_OP => [
self::TYPE_BIN_OP => [
self::ACTION_GOTO => self::EXPRESSION_TERNARY,
],
self::TYPE_ADD_OP => [
self::ACTION_GOTO => self::EXPRESSION_TERNARY,
],
self::TYPE_HOOK => [
self::ACTION_PUSH => self::EXPRESSION_TERNARY,
self::ACTION_GOTO => self::EXPRESSION_TERNARY,
],
self::TYPE_COMMA => [
self::ACTION_GOTO => self::EXPRESSION_TERNARY,
],
self::TYPE_PAREN_OPEN => [
self::ACTION_PUSH => self::EXPRESSION_TERNARY_OP,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_COLON => [
self::ACTION_POP => true,
],
],
self::EXPRESSION_TERNARY_FUNC => [
self::TYPE_BRACE_OPEN => [
self::ACTION_PUSH => self::EXPRESSION_TERNARY_OP,
self::ACTION_GOTO => self::STATEMENT,
],
],
self::PAREN_EXPRESSION => [
self::TYPE_BRACE_OPEN => [
self::ACTION_PUSH => self::PAREN_EXPRESSION_OP,
self::ACTION_GOTO => self::PROPERTY_ASSIGNMENT,
],
self::TYPE_PAREN_OPEN => [
self::ACTION_PUSH => self::PAREN_EXPRESSION_OP,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_PAREN_CLOSE => [
self::ACTION_POP => true,
],
self::TYPE_FUNC => [
self::ACTION_GOTO => self::PAREN_EXPRESSION_FUNC,
],
self::TYPE_LITERAL => [
self::ACTION_GOTO => self::PAREN_EXPRESSION_OP,
],
],
self::PAREN_EXPRESSION_OP => [
self::TYPE_BIN_OP => [
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_ADD_OP => [
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_HOOK => [
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_COLON => [
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_COMMA => [
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_SEMICOLON => [
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_PAREN_OPEN => [
self::ACTION_PUSH => self::PAREN_EXPRESSION_OP,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_PAREN_CLOSE => [
self::ACTION_POP => true,
],
],
self::PAREN_EXPRESSION_FUNC => [
self::TYPE_BRACE_OPEN => [
self::ACTION_PUSH => self::PAREN_EXPRESSION_OP,
self::ACTION_GOTO => self::STATEMENT,
],
],
// Property expression - The value of a key in an object literal.
self::PROPERTY_EXPRESSION => [
self::TYPE_BRACE_OPEN => [
self::ACTION_PUSH => self::PROPERTY_EXPRESSION_OP,
self::ACTION_GOTO => self::PROPERTY_ASSIGNMENT,
],
self::TYPE_BRACE_CLOSE => [
self::ACTION_POP => true,
],
self::TYPE_PAREN_OPEN => [
self::ACTION_PUSH => self::PROPERTY_EXPRESSION_OP,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
self::TYPE_FUNC => [
self::ACTION_GOTO => self::PROPERTY_EXPRESSION_FUNC,
],
self::TYPE_LITERAL => [
self::ACTION_GOTO => self::PROPERTY_EXPRESSION_OP,
],
],
self::PROPERTY_EXPRESSION_OP => [
self::TYPE_BIN_OP => [
self::ACTION_GOTO => self::PROPERTY_EXPRESSION,
],
self::TYPE_ADD_OP => [
self::ACTION_GOTO => self::PROPERTY_EXPRESSION,
],
self::TYPE_HOOK => [
self::ACTION_PUSH => self::PROPERTY_EXPRESSION,
self::ACTION_GOTO => self::EXPRESSION_TERNARY,
],
self::TYPE_COMMA => [
self::ACTION_GOTO => self::PROPERTY_ASSIGNMENT,
],
self::TYPE_BRACE_OPEN => [
self::ACTION_PUSH => self::PROPERTY_EXPRESSION_OP,
],
self::TYPE_BRACE_CLOSE => [
self::ACTION_POP => true,
],
self::TYPE_PAREN_OPEN => [
self::ACTION_PUSH => self::PROPERTY_EXPRESSION_OP,
self::ACTION_GOTO => self::PAREN_EXPRESSION,
],
],
self::PROPERTY_EXPRESSION_FUNC => [
self::TYPE_BRACE_OPEN => [
self::ACTION_PUSH => self::PROPERTY_EXPRESSION_OP,
self::ACTION_GOTO => self::STATEMENT,
],
],
];
// $semicolon : Rules for when a semicolon insertion is appropriate
$semicolon = [
self::EXPRESSION_NO_NL => [
self::TYPE_UN_OP => true,
self::TYPE_INCR_OP => true,
self::TYPE_ADD_OP => true,
self::TYPE_BRACE_OPEN => true,
self::TYPE_PAREN_OPEN => true,
self::TYPE_RETURN => true,
self::TYPE_IF => true,
self::TYPE_DO => true,
self::TYPE_FUNC => true,
self::TYPE_LITERAL => true
],
self::EXPRESSION_OP => [
self::TYPE_UN_OP => true,
self::TYPE_INCR_OP => true,
self::TYPE_BRACE_OPEN => true,
self::TYPE_RETURN => true,
self::TYPE_IF => true,
self::TYPE_DO => true,
self::TYPE_FUNC => true,
self::TYPE_LITERAL => true
]
];
// $divStates : Contains all states that can be followed by a division operator
$divStates = [
self::EXPRESSION_OP => true,
self::EXPRESSION_TERNARY_OP => true,
self::PAREN_EXPRESSION_OP => true,
self::PROPERTY_EXPRESSION_OP => true
];
// Here's where the minifying takes place: Loop through the input, looking for tokens
// and output them to $out, taking actions to the above defined rules when appropriate.
$out = '';
$pos = 0;
$length = strlen( $s );
$lineLength = 0;
$newlineFound = true;
$state = self::STATEMENT;
$stack = [];
$last = ';'; // Pretend that we have seen a semicolon yet
while ( $pos < $length ) {
// First, skip over any whitespace and multiline comments, recording whether we
// found any newline character
$skip = strspn( $s, " \t\n\r\xb\xc", $pos );
if ( !$skip ) {
$ch = $s[$pos];
if ( $ch === '/' && substr( $s, $pos, 2 ) === '/*' ) {
// Multiline comment. Search for the end token or EOT.
$end = strpos( $s, '*/', $pos + 2 );
$skip = $end === false ? $length - $pos : $end - $pos + 2;
}
}
if ( $skip ) {
// The semicolon insertion mechanism needs to know whether there was a newline
// between two tokens, so record it now.
if ( !$newlineFound && strcspn( $s, "\r\n", $pos, $skip ) !== $skip ) {
$newlineFound = true;
}
$pos += $skip;
continue;
}
// Handle C++-style comments and html comments, which are treated as single line
// comments by the browser, regardless of whether the end tag is on the same line.
// Handle --> the same way, but only if it's at the beginning of the line
if ( ( $ch === '/' && substr( $s, $pos, 2 ) === '//' )
|| ( $ch === '<' && substr( $s, $pos, 4 ) === '<!--' )
|| ( $ch === '-' && $newlineFound && substr( $s, $pos, 3 ) === '-->' )
) {
$pos += strcspn( $s, "\r\n", $pos );
continue;
}
// Find out which kind of token we're handling.
// Note: $end must point past the end of the current token
// so that `substr($s, $pos, $end - $pos)` would be the entire token.
// In order words, $end will be the offset of the last relevant character
// in the stream + 1, or simply put: The offset of the first character
// of any next token in the stream.
$end = $pos + 1;
// Handle string literals
if ( $ch === "'" || $ch === '"' ) {
// Search to the end of the string literal, skipping over backslash escapes
$search = $ch . '\\';
do{
// Speculatively add 2 to the end so that if we see a backslash,
// the next iteration will start 2 characters further (one for the
// backslash, one for the escaped character).
// We'll correct this outside the loop.
$end += strcspn( $s, $search, $end ) + 2;
// If the last character in our search for a quote or a backlash
// matched a backslash and we haven't reached the end, keep searching..
} while ( $end - 2 < $length && $s[$end - 2] === '\\' );
// Correction (1): Undo speculative add, keep only one (end of string literal)
$end--;
if ( $end > $length ) {
// Correction (2): Loop wrongly assumed an end quote ended the search,
// but search ended because we've reached the end. Correct $end.
// TODO: This is invalid and should throw.
$end--;
}
// We have to distinguish between regexp literals and division operators
// A division operator is only possible in certain states
} elseif ( $ch === '/' && !isset( $divStates[$state] ) ) {
// Regexp literal
for ( ; ; ) {
// Search until we find "/" (end of regexp), "\" (backslash escapes),
// or "[" (start of character classes).
do{
// Speculatively add 2 to ensure next iteration skips
// over backslash and escaped character.
// We'll correct this outside the loop.
$end += strcspn( $s, '/[\\', $end ) + 2;
// If backslash escape, keep searching...
} while ( $end - 2 < $length && $s[$end - 2] === '\\' );
// Correction (1): Undo speculative add, keep only one (end of regexp)
$end--;
if ( $end > $length ) {
// Correction (2): Loop wrongly assumed end slash was seen
// String ended without end of regexp. Correct $end.
// TODO: This is invalid and should throw.
$end--;
break;
}
if ( $s[$end - 1] === '/' ) {
break;
}
// (Implicit else), we must've found the start of a char class,
// skip until we find "]" (end of char class), or "\" (backslash escape)
do{
// Speculatively add 2 for backslash escape.
// We'll substract one outside the loop.
$end += strcspn( $s, ']\\', $end ) + 2;
// If backslash escape, keep searching...
} while ( $end - 2 < $length && $s[$end - 2] === '\\' );
// Correction (1): Undo speculative add, keep only one (end of regexp)
$end--;
if ( $end > $length ) {
// Correction (2): Loop wrongly assumed "]" was seen
// String ended without ending char class or regexp. Correct $end.
// TODO: This is invalid and should throw.
$end--;
break;
}
}
// Search past the regexp modifiers (gi)
while ( $end < $length && ctype_alpha( $s[$end] ) ) {
$end++;
}
} elseif (
$ch === '0'
&& ( $pos + 1 < $length ) && ( $s[$pos + 1] === 'x' || $s[$pos + 1] === 'X' )
) {
// Hex numeric literal
$end++; // x or X
$len = strspn( $s, '0123456789ABCDEFabcdef', $end );
if ( !$len ) {
return self::parseError(
$s,
$pos,
'Expected a hexadecimal number but found ' . substr( $s, $pos, 5 ) . '...'
);
}
$end += $len;
} elseif (
ctype_digit( $ch )
|| ( $ch === '.' && $pos + 1 < $length && ctype_digit( $s[$pos + 1] ) )
) {
$end += strspn( $s, '0123456789', $end );
$decimal = strspn( $s, '.', $end );
if ( $decimal ) {
if ( $decimal > 2 ) {
return self::parseError( $s, $end, 'The number has too many decimal points' );
}
$end += strspn( $s, '0123456789', $end + 1 ) + $decimal;
}
$exponent = strspn( $s, 'eE', $end );
if ( $exponent ) {
if ( $exponent > 1 ) {
return self::parseError( $s, $end, 'Number with several E' );
}
$end++;
// + sign is optional; - sign is required.
$end += strspn( $s, '-+', $end );
$len = strspn( $s, '0123456789', $end );
if ( !$len ) {
return self::parseError(
$s,
$pos,
'No decimal digits after e, how many zeroes should be added?'
);
}
$end += $len;
}
} elseif ( isset( $opChars[$ch] ) ) {
// Punctuation character. Search for the longest matching operator.
while (
$end < $length
&& isset( $tokenTypes[substr( $s, $pos, $end - $pos + 1 )] )
) {
$end++;
}
} else {
// Identifier or reserved word. Search for the end by excluding whitespace and
// punctuation.
$end += strcspn( $s, " \t\n.;,=<>+-{}()[]?:*/%'\"!&|^~\xb\xc\r", $end );
}
// Now get the token type from our type array
$token = substr( $s, $pos, $end - $pos ); // so $end - $pos == strlen( $token )
$type = $tokenTypes[$token] ?? self::TYPE_LITERAL;
if ( $newlineFound && isset( $semicolon[$state][$type] ) ) {
// This token triggers the semicolon insertion mechanism of javascript. While we
// could add the ; token here ourselves, keeping the newline has a few advantages.
$out .= "\n";
$state = self::STATEMENT;
$lineLength = 0;
} elseif ( $lineLength + $end - $pos > self::$maxLineLength &&
!isset( $semicolon[$state][$type] ) && $type !== self::TYPE_INCR_OP ) {
// This line would get too long if we added $token, so add a newline first.
// Only do this if it won't trigger semicolon insertion and if it won't
// put a postfix increment operator on its own line, which is illegal in js.
$out .= "\n";
$lineLength = 0;
// Check, whether we have to separate the token from the last one with whitespace
} elseif ( !isset( $opChars[$last] ) && !isset( $opChars[$ch] ) ) {
$out .= ' ';
$lineLength++;
// Don't accidentally create ++, -- or // tokens
} elseif ( $last === $ch && ( $ch === '+' || $ch === '-' || $ch === '/' ) ) {
$out .= ' ';
$lineLength++;
}
if (
$type === self::TYPE_LITERAL
&& ( $token === 'true' || $token === 'false' )
&& ( $state === self::EXPRESSION || $state === self::PROPERTY_EXPRESSION )
&& $last !== '.'
) {
$token = ( $token === 'true' ) ? '!0' : '!1';
}
$out .= $token;
$lineLength += $end - $pos; // += strlen( $token )
$last = $s[$end - 1];
$pos = $end;
$newlineFound = false;
// Now that we have output our token, transition into the new state.
if ( isset( $model[$state][$type][self::ACTION_PUSH] ) &&
count( $stack ) < self::STACK_LIMIT
) {
$stack[] = $model[$state][$type][self::ACTION_PUSH];
}
if ( $stack && isset( $model[$state][$type][self::ACTION_POP] ) ) {
$state = array_pop( $stack );
} elseif ( isset( $model[$state][$type][self::ACTION_GOTO] ) ) {
$state = $model[$state][$type][self::ACTION_GOTO];
}
}
return $out;
}
static function parseError( $fullJavascript, $position, $errorMsg ) {
// TODO: Handle the error: trigger_error, throw exception, return false...
return false;
}
}
Zerion Mini Shell 1.0