JSMin_lib.php

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<?php
define('JSMIN_VERSION', '0.2');

define('EOF', false);

define('ORD_NL', ord("\n"));
define('ORD_space', ord(' '));
define('ORD_cA', ord('A'));
define('ORD_cZ', ord('Z'));
define('ORD_a', ord('a'));
define('ORD_z', ord('z'));
define('ORD_0', ord('0'));
define('ORD_9', ord('9'));

/*
class JSMinException extends Exception {
}
*/
class JSMinException
{
}

class FileOpenFailedJSMinException extends JSMinException
{
}

class UnterminatedCommentJSMinException extends JSMinException
{
}

class UnterminatedStringLiteralJSMinException extends JSMinException
{
}

class UnterminatedRegExpLiteralJSMinException extends JSMinException
{
}

define('JSMIN_ACT_FULL', 1);

define('JSMIN_ACT_BUF', 2);

define('JSMIN_ACT_IMM', 3);

class JSMin
{

    public $in;

    public $out;

    public $theA;

    public $theB;

    public $inLength = 0;
    public $inPos = 0;
    public $isString = false;

    public function isAlphaNum($c)
    {

        // Get ASCII value of character for C-like comparisons

        $a = ord($c);

        // Compare using defined character ordinals, or between PHP strings
        // Note : === is micro-faster than == when types are known to be the same

        return
            ($a >= ORD_a && $a <= ORD_z) ||
            ($a >= ORD_0 && $a <= ORD_9) ||
            ($a >= ORD_cA && $a <= ORD_cZ) ||
            $c === '_' || $c === '$' || $c === '\\' || $a > 126
        ;
    }

    public function get()
    {

        // Get next input character and advance position in file

        if ($this->isString) {
            if ($this->inPos < $this->inLength) {
                $c = $this->in[$this->inPos];
                ++$this->inPos;
            } else {
                return EOF;
            }
        } else {
            $c = $this->in->fgetc();
        }

        // Test for non-problematic characters

        if ($c === "\n" || $c === EOF || ord($c) >= ORD_space) {
            return $c;
        }

        // else
        // Make linefeeds into newlines

        if ($c === "\r") {
            return "\n";
        }

        // else
        // Consider space

        return ' ';
    }

    public function peek()
    {
        if ($this->isString) {
            if ($this->inPos < $this->inLength) {
                $c = $this->in[$this->inPos];
            } else {
                return EOF;
            }
        } else {
            // Get next input character

            $c = $this->in->fgetc();

            // Regress position in file

            $this->in->fseek(-1, SEEK_CUR);

            // Return character obtained
        }

        return $c;
    }

    public function put($c)
    {
        if ($this->isString) {
            $this->out .= $c;
        } else {
            $this->out->fwrite($c);
        }
    }

    public function next()
    {

        // Get next char from input, translated if necessary

        $c = $this->get();

        // Check comment possibility

        if ($c == '/') {

            // Look ahead : a comment is two slashes or slashes followed by asterisk (to be closed)

            switch ($this->peek()) {

                case '/':

                    // Comment is up to the end of the line
                    // TOTEST : simple $this->in->fgets()

                    while (true) {
                        $c = $this->get();

                        if (ord($c) <= ORD_NL) {
                            return $c;
                        }
                    }

                    // no break
                case '*':

                    // Comment is up to comment close.
                    // Might not be terminated, if we hit the end of file.

                    while (true) {

                        // N.B. not using switch() because of having to test EOF with ===

                        $c = $this->get();

                        if ($c == '*') {

                            // Comment termination if the char ahead is a slash

                            if ($this->peek() == '/') {

                                // Advance again and make into a single space

                                $this->get();
                                return ' ';
                            }
                        } elseif ($c === EOF) {

                            // Whoopsie

                            //throw new UnterminatedCommentJSMinException();
                            trigger_error('UnterminatedComment', E_USER_ERROR);
                        }
                    }

                    // no break
                default:

                    // Not a comment after all

                    return $c;
            }
        }

        // No risk of a comment

        return $c;
    }

    public function action($action)
    {

        // Choice of possible actions
        // Note the frequent fallthroughs : the actions are decrementally "long"

        switch ($action) {

            case JSMIN_ACT_FULL:

                // Write A to output, then fall through

                $this->put($this->theA);

                // no break
            case JSMIN_ACT_BUF: // N.B. possible fallthrough from above

                // Copy B to A

                $tmpA = $this->theA = $this->theB;

                // Treating a string as a single char : outputting it whole
                // Note that the string-opening char (" or ') is memorized in B

                if ($tmpA == '\'' || $tmpA == '"') {
                    while (true) {

                        // Output string contents

                        $this->put($tmpA);

                        // Get next character, watching out for termination of the current string,
                        // new line & co (then the string is not terminated !), or a backslash
                        // (upon which the following char is directly output to serve the escape mechanism)

                        $tmpA = $this->theA = $this->get();

                        if ($tmpA == $this->theB) {

                            // String terminated

                            break; // from while(true)
                        }

                        // else

                        if (ord($tmpA) <= ORD_NL) {

                            // Whoopsie

                            //throw new UnterminatedStringLiteralJSMinException();
                            trigger_error('UnterminatedStringLiteral', E_USER_ERROR);
                        }

                        // else

                        if ($tmpA == '\\') {

                            // Escape next char immediately

                            $this->put($tmpA);
                            $tmpA = $this->theA = $this->get();
                        }
                    }
                }

                // no break
            case JSMIN_ACT_IMM: // N.B. possible fallthrough from above

                // Get the next B

                $this->theB = $this->next();

                // Special case of recognising regular expressions (beginning with /) that are
                // preceded by '(', ',' or '='

                $tmpA = $this->theA;

                if ($this->theB == '/' && ($tmpA == '(' || $tmpA == ',' || $tmpA == '=')) {

                    // Output the two successive chars

                    $this->put($tmpA);
                    $this->put($this->theB);

                    // Look for the end of the RE literal, watching out for escaped chars or a control /
                    // end of line char (the RE literal then being unterminated !)

                    while (true) {
                        $tmpA = $this->theA = $this->get();

                        if ($tmpA == '/') {

                            // RE literal terminated

                            break; // from while(true)
                        }

                        // else

                        if ($tmpA == '\\') {

                            // Escape next char immediately

                            $this->put($tmpA);
                            $tmpA = $this->theA = $this->get();
                        } elseif (ord($tmpA) <= ORD_NL) {

                            // Whoopsie

                            //throw new UnterminatedRegExpLiteralJSMinException();
                            trigger_error('UnterminatedRegExpLiteral', E_USER_ERROR);
                        }

                        // Output RE characters

                        $this->put($tmpA);
                    }

                    // Move forward after the RE literal

                    $this->theB = $this->next();
                }

            break;
            default:
                //throw new JSMinException('Expected a JSMin::ACT_* constant in action().');
                trigger_error('Expected a JSMin::ACT_* constant in action()', E_USER_ERROR);
        }
    }

    public function minify()
    {

        // Initialize A and run the first (minimal) action

        $this->theA = "\n";
        $this->action(JSMIN_ACT_IMM);

        // Proceed all the way to the end of the input file

        while ($this->theA !== EOF) {
            switch ($this->theA) {

                case ' ':

                    if (JSMin::isAlphaNum($this->theB)) {
                        $this->action(JSMIN_ACT_FULL);
                    } else {
                        $this->action(JSMIN_ACT_BUF);
                    }

                break;
                case "\n":

                    switch ($this->theB) {

                        case '{': case '[': case '(':
                        case '+': case '-':

                            $this->action(JSMIN_ACT_FULL);

                        break;
                        case ' ':

                            $this->action(JSMIN_ACT_IMM);

                        break;
                        default:

                            if (JSMin::isAlphaNum($this->theB)) {
                                $this->action(JSMIN_ACT_FULL);
                            } else {
                                $this->action(JSMIN_ACT_BUF);
                            }

                        break;
                    }

                break;
                default:

                    switch ($this->theB) {

                        case ' ':

                            if (JSMin::isAlphaNum($this->theA)) {
                                $this->action(JSMIN_ACT_FULL);
                                break;
                            }

                            // else

                            $this->action(JSMIN_ACT_IMM);

                        break;
                        case "\n":

                            switch ($this->theA) {

                                case '}': case ']': case ')': case '+':
                                case '-': case '"': case '\'':

                                    $this->action(JSMIN_ACT_FULL);

                                break;
                                default:

                                    if (JSMin::isAlphaNum($this->theA)) {
                                        $this->action(JSMIN_ACT_FULL);
                                    } else {
                                        $this->action(JSMIN_ACT_IMM);
                                    }

                                break;
                            }

                        break;
                        default:

                            $this->action(JSMIN_ACT_FULL);

                        break;
                    }

                break;
            }
        }

        if ($this->isString) {
            return $this->out;
        }
    }

    public function __construct($inFileName = '-', $outFileName = '-', $comments = null)
    {
        if ($outFileName === false) {
            $this->JSMin_String($inFileName, $comments);
        } else {
            $this->JSMin_File($inFileName, $outFileName, $comments);
        }
    }

    public function JSMin_File($inFileName = '-', $outFileName = '-', $comments = null)
    {

        // Recuperate input and output streams.
        // Use STDIN and STDOUT by default, if they are defined (CLI mode) and no file names are provided

        if ($inFileName == '-') {
            $inFileName  = 'php://stdin';
        }
        if ($outFileName == '-') {
            $outFileName = 'php://stdout';
        }

        /*try {

            $this->in = new SplFileObject($inFileName, 'rb', TRUE);
        }
        catch (Exception $e) {

            throw new FileOpenFailedJSMinException(
                'Failed to open "'.$inFileName.'" for reading only.'
            );
        }

        try {

            $this->out = new SplFileObject($outFileName, 'wb', TRUE);
        }
        catch (Exception $e) {

            throw new FileOpenFailedJSMinException(
                'Failed to open "'.$outFileName.'" for writing only.'
            );
        }
        */
        $this->in = fopen($inFileName, 'rb');
        if (!$this->in) {
            trigger_error('Failed to open "' . $inFileName, E_USER_ERROR);
        }
        $this->out = fopen($outFileName, 'wb');
        if (!$this->out) {
            trigger_error('Failed to open "' . $outFileName, E_USER_ERROR);
        }

        // Present possible initial comments

        if ($comments !== null) {
            foreach ($comments as $comm) {
                $this->out->fwrite('// ' . str_replace("\n", " ", $comm) . "\n");
            }
        }
    }

    public function JSMin_String($inString, $comments = null)
    {
        $this->in = $inString;
        $this->out = '';
        $this->inLength = strlen($inString);
        $this->inPos = 0;
        $this->isString = true;

        if ($comments !== null) {
            foreach ($comments as $comm) {
                $this->out .= '// ' . str_replace("\n", " ", $comm) . "\n";
            }
        }
    }
}