///                MentOS, The Mentoring Operating system project
/// @file ctype.c
/// @brief Functions related to character handling.
/// @copyright (c) 2014-2021 This file is distributed under the MIT License.
/// See LICENSE.md for details.

#include "ctype.h"

/// Distance from a uppercase character to the correspondent lowercase in ASCII.
#define OFFSET 32

int isdigit(int c)
{
    return (c >= 48 && c <= 57);
}

int isalpha(int c)
{
    return ((c >= 65 && c <= 90) || (c >= 97 && c <= 122));
}

int isalnum(int c)
{
    return (isalpha(c) || isdigit(c));
}

int isxdigit(int c)
{
    return (isdigit(c) || (c >= 65 && c <= 70));
}

int islower(int c)
{
    return (c >= 97 && c <= 122);
}

int isupper(int c)
{
    return (c >= 65 && c <= 90);
}

int tolower(int c)
{
    if (isalpha(c) == 0 || islower(c)) {
        return c;
    }

    return c + OFFSET;
}

int toupper(int c)
{
    if (isalpha(c) == 0 || isupper(c)) {
        return c;
    }

    return c - OFFSET;
}

int isspace(int c)
{
    return (c == ' ');
}