"String utilities"

CHAR_TO_INT = {
    "\0": 0,
    "\1": 1,
    "\2": 2,
    "\3": 3,
    "\4": 4,
    "\5": 5,
    "\6": 6,
    "\7": 7,
    "\10": 8,
    "\11": 9,
    "\12": 10,
    "\13": 11,
    "\14": 12,
    "\15": 13,
    "\16": 14,
    "\17": 15,
    "\20": 16,
    "\21": 17,
    "\22": 18,
    "\23": 19,
    "\24": 20,
    "\25": 21,
    "\26": 22,
    "\27": 23,
    "\30": 24,
    "\31": 25,
    "\32": 26,
    "\33": 27,
    "\34": 28,
    "\35": 29,
    "\36": 30,
    "\37": 31,
    "\40": 32,
    "\41": 33,
    "\42": 34,
    "\43": 35,
    "\44": 36,
    "\45": 37,
    "\46": 38,
    "\47": 39,
    "\50": 40,
    "\51": 41,
    "\52": 42,
    "\53": 43,
    "\54": 44,
    "\55": 45,
    "\56": 46,
    "\57": 47,
    "\60": 48,
    "\61": 49,
    "\62": 50,
    "\63": 51,
    "\64": 52,
    "\65": 53,
    "\66": 54,
    "\67": 55,
    "\70": 56,
    "\71": 57,
    "\72": 58,
    "\73": 59,
    "\74": 60,
    "\75": 61,
    "\76": 62,
    "\77": 63,
    "\100": 64,
    "\101": 65,
    "\102": 66,
    "\103": 67,
    "\104": 68,
    "\105": 69,
    "\106": 70,
    "\107": 71,
    "\110": 72,
    "\111": 73,
    "\112": 74,
    "\113": 75,
    "\114": 76,
    "\115": 77,
    "\116": 78,
    "\117": 79,
    "\120": 80,
    "\121": 81,
    "\122": 82,
    "\123": 83,
    "\124": 84,
    "\125": 85,
    "\126": 86,
    "\127": 87,
    "\130": 88,
    "\131": 89,
    "\132": 90,
    "\133": 91,
    "\134": 92,
    "\135": 93,
    "\136": 94,
    "\137": 95,
    "\140": 96,
    "\141": 97,
    "\142": 98,
    "\143": 99,
    "\144": 100,
    "\145": 101,
    "\146": 102,
    "\147": 103,
    "\150": 104,
    "\151": 105,
    "\152": 106,
    "\153": 107,
    "\154": 108,
    "\155": 109,
    "\156": 110,
    "\157": 111,
    "\160": 112,
    "\161": 113,
    "\162": 114,
    "\163": 115,
    "\164": 116,
    "\165": 117,
    "\166": 118,
    "\167": 119,
    "\170": 120,
    "\171": 121,
    "\172": 122,
    "\173": 123,
    "\174": 124,
    "\175": 125,
    "\176": 126,
    "\177": 127,
    "\200": 128,
    "\201": 129,
    "\202": 130,
    "\203": 131,
    "\204": 132,
    "\205": 133,
    "\206": 134,
    "\207": 135,
    "\210": 136,
    "\211": 137,
    "\212": 138,
    "\213": 139,
    "\214": 140,
    "\215": 141,
    "\216": 142,
    "\217": 143,
    "\220": 144,
    "\221": 145,
    "\222": 146,
    "\223": 147,
    "\224": 148,
    "\225": 149,
    "\226": 150,
    "\227": 151,
    "\230": 152,
    "\231": 153,
    "\232": 154,
    "\233": 155,
    "\234": 156,
    "\235": 157,
    "\236": 158,
    "\237": 159,
    "\240": 160,
    "\241": 161,
    "\242": 162,
    "\243": 163,
    "\244": 164,
    "\245": 165,
    "\246": 166,
    "\247": 167,
    "\250": 168,
    "\251": 169,
    "\252": 170,
    "\253": 171,
    "\254": 172,
    "\255": 173,
    "\256": 174,
    "\257": 175,
    "\260": 176,
    "\261": 177,
    "\262": 178,
    "\263": 179,
    "\264": 180,
    "\265": 181,
    "\266": 182,
    "\267": 183,
    "\270": 184,
    "\271": 185,
    "\272": 186,
    "\273": 187,
    "\274": 188,
    "\275": 189,
    "\276": 190,
    "\277": 191,
    "\300": 192,
    "\301": 193,
    "\302": 194,
    "\303": 195,
    "\304": 196,
    "\305": 197,
    "\306": 198,
    "\307": 199,
    "\310": 200,
    "\311": 201,
    "\312": 202,
    "\313": 203,
    "\314": 204,
    "\315": 205,
    "\316": 206,
    "\317": 207,
    "\320": 208,
    "\321": 209,
    "\322": 210,
    "\323": 211,
    "\324": 212,
    "\325": 213,
    "\326": 214,
    "\327": 215,
    "\330": 216,
    "\331": 217,
    "\332": 218,
    "\333": 219,
    "\334": 220,
    "\335": 221,
    "\336": 222,
    "\337": 223,
    "\340": 224,
    "\341": 225,
    "\342": 226,
    "\343": 227,
    "\344": 228,
    "\345": 229,
    "\346": 230,
    "\347": 231,
    "\350": 232,
    "\351": 233,
    "\352": 234,
    "\353": 235,
    "\354": 236,
    "\355": 237,
    "\356": 238,
    "\357": 239,
    "\360": 240,
    "\361": 241,
    "\362": 242,
    "\363": 243,
    "\364": 244,
    "\365": 245,
    "\366": 246,
    "\367": 247,
    "\370": 248,
    "\371": 249,
    "\372": 250,
    "\373": 251,
    "\374": 252,
    "\375": 253,
    "\376": 254,
    "\377": 255,
}

INT_TO_CHAR = [
    "\0",
    "\1",
    "\2",
    "\3",
    "\4",
    "\5",
    "\6",
    "\7",
    "\10",
    "\11",
    "\12",
    "\13",
    "\14",
    "\15",
    "\16",
    "\17",
    "\20",
    "\21",
    "\22",
    "\23",
    "\24",
    "\25",
    "\26",
    "\27",
    "\30",
    "\31",
    "\32",
    "\33",
    "\34",
    "\35",
    "\36",
    "\37",
    "\40",
    "\41",
    "\42",
    "\43",
    "\44",
    "\45",
    "\46",
    "\47",
    "\50",
    "\51",
    "\52",
    "\53",
    "\54",
    "\55",
    "\56",
    "\57",
    "\60",
    "\61",
    "\62",
    "\63",
    "\64",
    "\65",
    "\66",
    "\67",
    "\70",
    "\71",
    "\72",
    "\73",
    "\74",
    "\75",
    "\76",
    "\77",
    "\100",
    "\101",
    "\102",
    "\103",
    "\104",
    "\105",
    "\106",
    "\107",
    "\110",
    "\111",
    "\112",
    "\113",
    "\114",
    "\115",
    "\116",
    "\117",
    "\120",
    "\121",
    "\122",
    "\123",
    "\124",
    "\125",
    "\126",
    "\127",
    "\130",
    "\131",
    "\132",
    "\133",
    "\134",
    "\135",
    "\136",
    "\137",
    "\140",
    "\141",
    "\142",
    "\143",
    "\144",
    "\145",
    "\146",
    "\147",
    "\150",
    "\151",
    "\152",
    "\153",
    "\154",
    "\155",
    "\156",
    "\157",
    "\160",
    "\161",
    "\162",
    "\163",
    "\164",
    "\165",
    "\166",
    "\167",
    "\170",
    "\171",
    "\172",
    "\173",
    "\174",
    "\175",
    "\176",
    "\177",
    "\200",
    "\201",
    "\202",
    "\203",
    "\204",
    "\205",
    "\206",
    "\207",
    "\210",
    "\211",
    "\212",
    "\213",
    "\214",
    "\215",
    "\216",
    "\217",
    "\220",
    "\221",
    "\222",
    "\223",
    "\224",
    "\225",
    "\226",
    "\227",
    "\230",
    "\231",
    "\232",
    "\233",
    "\234",
    "\235",
    "\236",
    "\237",
    "\240",
    "\241",
    "\242",
    "\243",
    "\244",
    "\245",
    "\246",
    "\247",
    "\250",
    "\251",
    "\252",
    "\253",
    "\254",
    "\255",
    "\256",
    "\257",
    "\260",
    "\261",
    "\262",
    "\263",
    "\264",
    "\265",
    "\266",
    "\267",
    "\270",
    "\271",
    "\272",
    "\273",
    "\274",
    "\275",
    "\276",
    "\277",
    "\300",
    "\301",
    "\302",
    "\303",
    "\304",
    "\305",
    "\306",
    "\307",
    "\310",
    "\311",
    "\312",
    "\313",
    "\314",
    "\315",
    "\316",
    "\317",
    "\320",
    "\321",
    "\322",
    "\323",
    "\324",
    "\325",
    "\326",
    "\327",
    "\330",
    "\331",
    "\332",
    "\333",
    "\334",
    "\335",
    "\336",
    "\337",
    "\340",
    "\341",
    "\342",
    "\343",
    "\344",
    "\345",
    "\346",
    "\347",
    "\350",
    "\351",
    "\352",
    "\353",
    "\354",
    "\355",
    "\356",
    "\357",
    "\360",
    "\361",
    "\362",
    "\363",
    "\364",
    "\365",
    "\366",
    "\367",
    "\370",
    "\371",
    "\372",
    "\373",
    "\374",
    "\375",
    "\376",
    "\377",
]

def ord(c):
    """returns the codepoint of a character

    ord(c) returns the integer value of the sole Unicode code point
    encoded by the string `c`.

    If `c` does not encode exactly one Unicode code point, `ord` fails.
    Each invalid code within the string is treated as if it encodes the
    Unicode replacement character, U+FFFD.

    Args:
        c: character whose codepoint to be returned.

    Returns:
        codepoint of `c` argument.
    """
    if len(c) != 1:
        fail("expected a string with a single character")
    return CHAR_TO_INT.get(c)

def chr(i):
    """returns a string encoding a codepoint

    chr returns a string that encodes the single Unicode code
    point whose value is specified by the integer `i`

    Args:
        i: position of the character

    Returns:
        unicode string of the position
    """
    if i < 0 or i > 255:
        fail("expected a int between 0 and 255 (inclusive)")
    return INT_TO_CHAR[i]

def _to_char(n):
    alpha = "0123456789abcdef"
    return alpha[n]

def hex(number):
    """Format integer to hexdecimal representation

    Args:
        number: number to format

    Returns:
        hexdecimal representation of the number argument
    """

    hex_string = ""
    is_signed = number < 0
    r = number * -1 if is_signed else number
    for _ in range(1000000):
        if r > 0:
            rem = r % 16
            hex_string = _to_char(rem) + hex_string
            r //= 16
        else:
            break

    if not hex_string:
        hex_string = "0"

    return "{}0x{}".format("-" if is_signed else "", hex_string)