/* /_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
    charset = shift_jis

    +++ UTF8/16 ライブラリ +++


    LastModified : 2006-11/08
    
    Powered by kerry
    http://202.248.69.143/~goma/
    
    動作ブラウザ :: IE4+ , NN4.06+ , Gecko , Opera6+



    * [RFC 2279] UTF-8, a transformation format of ISO 10646
    ftp://ftp.isi.edu/in-notes/rfc2279.txt
    
    * [RFC 1738] Uniform Resource Locators (URL)
    ftp://ftp.isi.edu/in-notes/rfc1738.txt

    /_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
    
    Usage:
    
    // 文字列を UTF16 (文字コード) へ
    utf16code_array = utf.unpackUTF16( my_string );

    // 文字列を UTF8 (文字コード) へ
    utf8code_array = utf.unpackUTF8( my_string );
    
    // UTF8 (文字コード) から文字列へ。 utf.unpackUTF8() したものを元に戻す
    my_string = utf.packUTF8( utf8code_array );

    // UTF8/16 (文字コード) を文字列へ
    my_string = utf.packChar( utfCode_array );
    
    // UTF16 (文字コード) から UTF8 (文字コード) へ
    utf8code_array = utf.toUTF8( utf16code_array );
    
    // UTF8 (文字コード) から UTF16 (文字コード) へ
    utf16code_array = utf.toUTF16( utf8code_array );



    // URL 文字列へエンコード
    url_string = utf.URLencode( my_string );

    // URL 文字列からデコード
    my_string = utf.URLdecode( url_string );

    /_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ */



utf = new function()
{
    this.unpackUTF16 = function(_str)
    {
        var i, utf16=[];
        for (i=0; i<_str.length; i++) utf16[i] = _str.charCodeAt(i);
        return utf16;
    }
    
    this.unpackChar = function(_str) 
    {
    	var utf16 = this.unpackUTF16(_str);
    	var i,n, tmp = [];
    	for (n=i=0; i<utf16.length; i++) {
    		if (utf16[i]<=0xff) tmp[n++] = utf16[i];
    		else {
    			tmp[n++] = utf16[i] >> 8;
    			tmp[n++] = utf16[i] &  0xff;
    		}	
    	}
    	return tmp;
    }
    
    this.packChar  =
    this.packUTF16 = function(_utf16)
    {
        var i, str = "";
        for (i in _utf16) str += String.fromCharCode(_utf16[i]);
        return str;
    }

    this.unpackUTF8 = function(_str)
    {
       return this.toUTF8( this.unpackUTF16(_str) );
    }

    this.packUTF8 = function(_utf8)
    {
        return this.packUTF16( this.toUTF16(_utf8) );
    }
    
    this.toUTF8 = function(_utf16)
    {
        var utf8 = [];
        var idx = 0;
        var i, j, c;
        for (i=0; i<_utf16.length; i++)
        {
            c = _utf16[i];
            if (c <= 0x7f) utf8[idx++] = c;
            else if (c <= 0x7ff)
            {
                utf8[idx++] = 0xc0 | (c >>> 6 );
                utf8[idx++] = 0x80 | (c & 0x3f);
            }
            else if (c <= 0xffff)
            {
                utf8[idx++] = 0xe0 | (c >>> 12 );
                utf8[idx++] = 0x80 | ((c >>> 6 ) & 0x3f);
                utf8[idx++] = 0x80 | (c & 0x3f);
            }
            else
            {
                j = 4;
                while (c >> (6*j)) j++;
                utf8[idx++] = ((0xff00 >>> j) & 0xff) | (c >>> (6*--j) );
                while (j--) 
                utf8[idx++] = 0x80 | ((c >>> (6*j)) & 0x3f);
            }
        }
        return utf8;
    }
    
    this.toUTF16 = function(_utf8)
    {
        var utf16 = [];
        var idx = 0;
        var i,s;
        for (i=0; i<_utf8.length; i++, idx++)
        {
            if (_utf8[i] <= 0x7f) utf16[idx] = _utf8[i];
            else 
            {
                if ( (_utf8[i]>>5) == 0x6)
                {
                    utf16[idx] = ( (_utf8[i] & 0x1f) << 6 )
                                 | ( _utf8[++i] & 0x3f );
                }
                else if ( (_utf8[i]>>4) == 0xe)
                {
                    utf16[idx] = ( (_utf8[i] & 0xf) << 12 )
                                 | ( (_utf8[++i] & 0x3f) << 6 )
                                 | ( _utf8[++i] & 0x3f );
                }
                else
                {
                    s = 1;
                    while (_utf8[i] & (0x20 >>> s) ) s++;
                    utf16[idx] = _utf8[i] & (0x1f >>> s);
                    while (s-->=0) utf16[idx] = (utf16[idx] << 6) ^ (_utf8[++i] & 0x3f);
                }
            }
        }
        return utf16;
    }
    
    this.URLencode = function(_str)
    {
        return _str.replace(/([^a-zA-Z0-9_\-\.])/g, function(_tmp, _c)
            { 
                if (_c == "\x20") return "+";
                var tmp = utf.toUTF8( [_c.charCodeAt(0)] );
                var c = "";
                for (var i in tmp)
                {
                    i = tmp[i].toString(16);
                    if (i.length == 1) i = "0"+ i;
                    c += "%"+ i;
                }
                return c;
            } );
    }

    this.URLdecode = function(_dat)
    {
        _dat = _dat.replace(/\+/g, "\x20");
        _dat = _dat.replace( /%([a-fA-F0-9][a-fA-F0-9])/g, 
                function(_tmp, _hex){ return String.fromCharCode( parseInt(_hex, 16) ) } );
        return this.packChar( this.toUTF16( this.unpackUTF16(_dat) ) );
    }
}