codon/stdlib/internal/format.codon

# Copyright (C) 2022-2023 Exaloop Inc. <https://exaloop.io>

def _format_error(ret: str):
	raise ValueError(f"invalid format specifier: {ret}")

@extend
class int:
    def __format__(self, format_spec: str) -> str:
        err = False
        ret = _C.seq_str_int(self, format_spec, __ptr__(err))
        if format_spec and err:
            _format_error(ret)
        return ret

@extend
class Int:
    def __format__(self, format_spec: str) -> str:
        err = False
        ret = _C.seq_str_int(self.__int__(), format_spec, __ptr__(err))
        if format_spec and err:
            _format_error(ret)
        return ret

@extend
class UInt:
    def __format__(self, format_spec: str) -> str:
        err = False
        ret = _C.seq_str_uint(self.__int__(), format_spec, __ptr__(err))
        if format_spec and err:
            _format_error(ret)
        return ret

@extend
class float:
    def __format__(self, format_spec: str) -> str:
        err = False
        ret = _C.seq_str_float(self, format_spec, __ptr__(err))
        if format_spec and err:
            _format_error(ret)
        return ret if ret != "-nan" else "nan"

@extend
class str:
    def __format__(self, format_spec: str) -> str:
        err = False
        ret = _C.seq_str_str(self, format_spec, __ptr__(err))
        if format_spec and err:
            _format_error(ret)
        return ret

@extend
class Ptr:
    def __format__(self, format_spec: str) -> str:
        err = False
        ret = _C.seq_str_ptr(self.as_byte(), format_spec, __ptr__(err))
        if format_spec and err:
            _format_error(ret)
        return ret

def _divmod_10(dividend, N: Static[int]):
    T = type(dividend)
    zero, one = T(0), T(1)
    neg = dividend < zero
    dvd = dividend.__abs__()

    remainder = 0
    quotient = zero

    # Euclidean division
    for bit_idx in range(N - 1, -1, -1):
        mask = int((dvd & (one << T(bit_idx))) != zero)
        remainder = (remainder << 1) + mask
        if remainder >= 10:
            quotient = (quotient << one) + one
            remainder -= 10
        else:
            quotient = quotient << one

    if neg:
        quotient = -quotient
        remainder = -remainder

    return quotient, remainder

@extend
class Int:
    def __str__(self) -> str:
        if N <= 64:
            return str(int(self))

        if not self:
            return '0'

        s = _strbuf()
        d = self

        if d >= Int[N](0):
            while True:
                d, m = _divmod_10(d, N)
                b = byte(48 + m)  # 48 == ord('0')
                s.append(str(__ptr__(b), 1))
                if not d:
                    break
        else:
            while True:
                d, m = _divmod_10(d, N)
                b = byte(48 - m)  # 48 == ord('0')
                s.append(str(__ptr__(b), 1))

                if not d:
                    break
            s.append('-')

        s.reverse()
        return s.__str__()

@extend
class UInt:
    def __str__(self) -> str:
        if N <= 64:
            return self.__format__("")

        s = _strbuf()
        d = self

        while True:
            d, m = _divmod_10(d, N)
            b = byte(48 + int(m))  # 48 == ord('0')
            s.append(str(__ptr__(b), 1))
            if not d:
                break

        s.reverse()
        return s.__str__()