Metacat

/* jsmin.c

   2006-05-04

Copyright (c) 2002 Douglas Crockford  (www.crockford.com)

Permission is hereby granted, free of charge, to any person obtaining a copy of

this software and associated documentation files (the "Software"), to deal in

the Software without restriction, including without limitation the rights to

use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies

of the Software, and to permit persons to whom the Software is furnished to do

so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all

copies or substantial portions of the Software.

The Software shall be used for Good, not Evil.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

SOFTWARE.

*/

#include <stdlib.h>

#include <stdio.h>

static int   theA;

static int   theB;

static int   theLookahead = EOF;

/* isAlphanum -- return true if the character is a letter, digit, underscore,

        dollar sign, or non-ASCII character.

*/

static int

isAlphanum(int c)

{

    return ((c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') ||

        (c >= 'A' && c <= 'Z') || c == '_' || c == '$' || c == '\\' ||

        c > 126);

}

/* get -- return the next character from stdin. Watch out for lookahead. If

        the character is a control character, translate it to a space or

        linefeed.

*/

static int

get()

{

    int c = theLookahead;

    theLookahead = EOF;

    if (c == EOF) {

        c = getc(stdin);

    }

    if (c >= ' ' || c == '\n' || c == EOF) {

        return c;

    }

    if (c == '\r') {

        return '\n';

    }

    return ' ';

}

/* peek -- get the next character without getting it.

*/

static int

peek()

{

    theLookahead = get();

    return theLookahead;

}

/* next -- get the next character, excluding comments. peek() is used to see

        if a '/' is followed by a '/' or '*'.

*/

static int

next()

{

    int c = get();

    if  (c == '/') {

        switch (peek()) {

        case '/':

            for (;;) {

                c = get();

                if (c <= '\n') {

                    return c;

                }

            }

        case '*':

            get();

            for (;;) {

                switch (get()) {

                case '*':

                    if (peek() == '/') {

                        get();

                        return ' ';

                    }

                    break;

                case EOF:

                    fprintf(stderr, "Error: JSMIN Unterminated comment.\n");

                    exit(1);

                }

            }

        default:

            return c;

        }

    }

    return c;

}

/* action -- do something! What you do is determined by the argument:

        1   Output A. Copy B to A. Get the next B.

        2   Copy B to A. Get the next B. (Delete A).

        3   Get the next B. (Delete B).

   action treats a string as a single character. Wow!

   action recognizes a regular expression if it is preceded by ( or , or =.

*/

static void

action(int d)

{

    switch (d) {

    case 1:

        putc(theA, stdout);

    case 2:

        theA = theB;

        if (theA == '\'' || theA == '"') {

            for (;;) {

                putc(theA, stdout);

                theA = get();

                if (theA == theB) {

                    break;

                }

                if (theA <= '\n') {

                    fprintf(stderr,

"Error: JSMIN unterminated string literal: %c\n", theA);

                    exit(1);

                }

                if (theA == '\\') {

                    putc(theA, stdout);

                    theA = get();

                }

            }

        }

    case 3:

        theB = next();

        if (theB == '/' && (theA == '(' || theA == ',' || theA == '=' ||

                theA == ':' || theA == '[' || theA == '!' || theA == '&' ||

                theA == '|')) {

            putc(theA, stdout);

            putc(theB, stdout);

            for (;;) {

                theA = get();

                if (theA == '/') {

                    break;

                } else if (theA =='\\') {

                    putc(theA, stdout);

                    theA = get();

                } else if (theA <= '\n') {

                    fprintf(stderr,

"Error: JSMIN unterminated Regular Expression literal.\n", theA);

                    exit(1);

                }

                putc(theA, stdout);

            }

            theB = next();

        }

    }

}

/* jsmin -- Copy the input to the output, deleting the characters which are

        insignificant to JavaScript. Comments will be removed. Tabs will be

        replaced with spaces. Carriage returns will be replaced with linefeeds.

        Most spaces and linefeeds will be removed.

*/

static void

jsmin()

{

    theA = '\n';

    action(3);

    while (theA != EOF) {

        switch (theA) {

        case ' ':

            if (isAlphanum(theB)) {

                action(1);

            } else {

                action(2);

            }

            break;

        case '\n':

            switch (theB) {

            case '{':

            case '[':

            case '(':

            case '+':

            case '-':

                action(1);

                break;

            case ' ':

                action(3);

                break;

            default:

                if (isAlphanum(theB)) {

                    action(1);

                } else {

                    action(2);

                }

            }

            break;

        default:

            switch (theB) {

            case ' ':

                if (isAlphanum(theA)) {

                    action(1);

                    break;

                }

                action(3);

                break;

            case '\n':

                switch (theA) {

                case '}':

                case ']':

                case ')':

                case '+':

                case '-':

                case '"':

                case '\'':

                    action(1);

                    break;

                default:

                    if (isAlphanum(theA)) {

                        action(1);

                    } else {

                        action(3);

                    }

                }

                break;

            default:

                action(1);

                break;

            }

        }

    }

}

/* main -- Output any command line arguments as comments

        and then minify the input.

*/

extern int

main(int argc, char* argv[])

{

    int i;

    for (i = 1; i < argc; i += 1) {

        fprintf(stdout, "// %s\n", argv[i]);

    }

    jsmin();

    return 0;

}