module big

// from_json_number implements a custom decoder for json2
pub fn (mut result Integer) from_json_number(raw_number string) ! {
    mut index := 0
    mut is_negative := false

    if raw_number[0] == `-` {
        is_negative = true
        index++
    }

    ten := integer_from_int(10)

    for index < raw_number.len {
        digit := raw_number[index] - `0`

        if digit > 9 { // comma, e and E are all smaller 0 in ASCII so they underflow
            return error('expected integer but got real number')
        }

        result = (result * ten) + integer_from_int(int(digit))

        index++
    }

    if is_negative {
        result = result * integer_from_int(-1)
    }
}

// to_json implements a custom encoder for json2
pub fn (result Integer) to_json() string {
    return result.str()
}