efl/src/lib/eina/eina_convert.h

361 lines
11 KiB
C

/* EINA - EFL data type library
* Copyright (C) 2008 Cedric BAIL, Vincent Torri
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library;
* if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef EINA_CONVERT_H_
#define EINA_CONVERT_H_
#include "eina_types.h"
#include "eina_error.h"
#include "eina_fp.h"
/**
* @addtogroup Eina_Convert_Group Convert
*
* These functions allow you to convert integer or real numbers to
* string or conversely.
*
* To use these functions, you have to call eina_init()
* first, and eina_shutdown() when eina is not used anymore.
*
* @section Eina_Convert_From_Integer_To_String Conversion from integer to string
*
* To convert an integer to a string in the decimal base,
* eina_convert_itoa() should be used. If the hexadecimal base is
* wanted, eina_convert_xtoa() should be used. They all need a buffer
* sufficiently large to store all the cyphers.
*
* Here is an example of use:
*
* @code
* #include <stdlib.h>
* #include <stdio.h>
*
* #include <Eina.h>
*
* int main(void)
* {
* char tmp[128];
*
* if (!eina_init())
* {
* printf ("Error during the initialization of eina.\n");
* return EXIT_FAILURE;
* }
*
* eina_convert_itoa(45, tmp);
* printf("value: %s\n", tmp);
* eina_convert_xtoa(0xA1, tmp);
* printf("value: %s\n", tmp);
*
* eina_shutdown();
*
* return EXIT_SUCCESS;
* }
* @endcode
*
* Compile this code with the following command:
*
* @code
* gcc -Wall -o test_eina_convert test_eina.c `pkg-config --cflags --libs eina`
* @endcode
*
* @note
* The alphabetical cyphers are in lower case.
*
* @section Eina_Convert_Double Conversion double / string
*
* To convert a double to a string, eina_convert_dtoa() should be
* used. Like with the integer functions, a buffer must be used. The
* resulting string has the following format (which is the result
* obtained with snprintf() and the @%a modifier):
*
* @code
* [-]0xh.hhhhhp[+-]e
* @endcode
*
* To convert a string to a double, eina_convert_atod() should be
* used. The format of the string must be as above. Then, the double
* has the following mantissas and exponent:
*
* @code
* mantissa : [-]hhhhhh
* exponent : 2^([+-]e - 4 * n)
* @endcode
*
* with n being number of cyphers after the point in the string
* format. To obtain the double number from the mantissas and exponent,
* use ldexp().
*
* Here is an example of use:
*
* @code
* #include <stdlib.h>
* #include <stdio.h>
* #include <math.h>
*
* #include <Eina.h>
*
* int main(void)
* {
* char tmp[128];
* long long int m = 0;
* long int e = 0;
* double r;
*
* if (!eina_init())
* {
* printf ("Error during the initialization of eina.\n");
* return EXIT_FAILURE;
* }
*
* printf("initial value : 40.56\n");
* eina_convert_dtoa(40.56, tmp);
* printf("result dtoa : %s\n", tmp);
* eina_convert_atod(tmp, 128, &m, &e);
* r = ldexp((double)m, e);
* printf("result atod : %f\n", r);
*
* eina_shutdown();
*
* return EXIT_SUCCESS;
* }
* @endcode
*
* Compile this code with the following command:
*
* @code
* gcc -Wall -o test_eina_convert test_eina.c `pkg-config --cflags --libs eina` -lm
* @endcode
*/
/**
* @addtogroup Eina_Tools_Group Tools
*
* @{
*/
/**
* @defgroup Eina_Convert_Group Convert
*
* @{
*/
EAPI extern Eina_Error EINA_ERROR_CONVERT_P_NOT_FOUND; /**< Not used, perhaps a placeholder? Defined as 0 in eina_convert.c*/
EAPI extern Eina_Error EINA_ERROR_CONVERT_0X_NOT_FOUND; /**< Not used, perhaps a placeholder? Defined as 0 in eina_convert.c*/
EAPI extern Eina_Error EINA_ERROR_CONVERT_OUTRUN_STRING_LENGTH; /**< Not used, perhaps a placeholder? Defined as 0 in eina_convert.c*/
/**
* @brief Converts an integer number to a string in decimal base.
*
* @param[in] n The integer to convert.
* @param[out] s The buffer to store the converted integer.
* @return The length of the string, including the null terminated
* character.
*
* This function converts @p n to a null terminated string. The
* converted string is in decimal base. As no check is done, @p s must
* be a buffer that is sufficiently large to store the integer.
*
* The returned value is the length of the string, including the null
* terminated character.
*/
EAPI int eina_convert_itoa(int n, char *s) EINA_ARG_NONNULL(2);
/**
* @brief Converts an integer number to a string in hexadecimal base.
*
* @param[in] n The integer to convert.
* @param[out] s The buffer to store the converted integer.
* @return The length of the string, including the null terminated
* character.
*
* This function converts @p n to a null terminated string. The
* converted string is in hexadecimal base and the alphabetical
* cyphers are in lower case. As no check is done, @p s must be a
* buffer that is sufficiently large to store the integer.
*
* The returned value is the length of the string, including the nul
* terminated character.
*/
EAPI int eina_convert_xtoa(unsigned int n, char *s) EINA_ARG_NONNULL(2);
/**
* @brief Converts a double to a string.
*
* @param[in] d The double to convert.
* @param[out] des The destination buffer to store the converted double.
* @return #EINA_TRUE on success, #EINA_FALSE otherwise.
*
* This function converts the double @p d to a string. The string is
* stored in the buffer pointed by @p des and must be sufficiently
* large to contain the converted double. The returned string is null
* terminated and has the following format:
*
* @code
* [-]0xh.hhhhhp[+-]e
* @endcode
*
* where the h are the hexadecimal cyphers of the mantissas and e the
* exponent (a decimal number).
*
* The returned value is the length of the string, including the null
* character.
*/
EAPI int eina_convert_dtoa(double d, char *des) EINA_ARG_NONNULL(2);
/**
* @brief Converts a string to a double.
*
* @param[in] src The string to convert.
* @param[in] length The length of the string.
* @param[out] m The mantissa.
* @param[out] e The exponent.
* @return #EINA_TRUE on success, #EINA_FALSE otherwise.
*
* This function converts the string @p s of length @p length that
* represent a double in hexadecimal base to a double. It is used to
* replace the use of snprintf() with the \%a modifier, which is
* missing on some platform (like Windows (tm) or OpenBSD).
*
* The string must have the following format:
*
* @code
* [-]0xh.hhhhhp[+-]e
* @endcode
*
* where the h are the hexadecimal cyphers of the mantissas and e the
* exponent (a decimal number). If n is the number of cyphers after the
* point, the returned mantissas and exponents are:
*
* @code
* mantissa : [-]hhhhhh
* exponent : 2^([+-]e - 4 * n)
* @endcode
*
* The mantissas and exponent are stored in the buffers pointed
* respectively by @p m and @p e.
*
* If the string is invalid #EINA_FALSE is returned, otherwise #EINA_TRUE is
* returned.
*/
EAPI Eina_Bool eina_convert_atod(const char *src,
int length,
long long *m,
long *e) EINA_ARG_NONNULL(1, 3, 4);
/**
* @brief Converts a 32.32 fixed point number to a string.
*
* @param[in] fp The fixed point number to convert.
* @param[out] des The destination buffer to store the converted fixed point number.
* @return #EINA_TRUE on success, #EINA_FALSE otherwise.
*
* This function converts the 32.32 fixed point number @p fp to a
* string. The string is stored in the buffer pointed by @p des and
* must be sufficiently large to contain the converted fixed point
* number. The returned string is terminated and has the following
* format:
*
* @code
* [-]0xh.hhhhhp[+-]e
* @endcode
*
* where the h are the hexadecimal cyphers of the mantissas and e the
* exponent (a decimal number).
*
* The returned value is the length of the string, including the null
* character.
*
* @note The code is the same than eina_convert_dtoa() except that it
* implements the frexp() function for fixed point numbers and does
* some optimization.
*/
EAPI int eina_convert_fptoa(Eina_F32p32 fp,
char *des) EINA_ARG_NONNULL(2);
/**
* @brief Converts a string to a 32.32 fixed point number.
*
* @param[in] src The string to convert.
* @param[in] length The length of the string.
* @param[out] fp The fixed point number.
* @return #EINA_TRUE on success, #EINA_FALSE otherwise.
*
* This function converts the string @p src of length @p length that
* represent a double in hexadecimal base to a 32.32 fixed point
* number stored in @p fp. The function always tries to convert the
* string with eina_convert_atod().
*
* The string must have the following format:
*
* @code
* [-]0xh.hhhhhp[+-]e
* @endcode
*
* where the h's are the hexadecimal cyphers of the mantissas and e the
* exponent (a decimal number). If n is the number of cyphers after the
* point, the returned mantissas and exponents are:
*
* @code
* mantissa : [-]hhhhhh
* exponent : 2^([+-]e - 4 * n)
* @endcode
*
* The mantissas and exponent are stored in the buffers pointed
* respectively by @p m and @p e.
*
* If the string is invalid, #EINA_FALSE is returned,
* otherwise @p fp is computed and #EINA_TRUE is returned.
*
* @note The code uses eina_convert_atod() and do the correct bit
* shift to compute the fixed point number.
*/
EAPI Eina_Bool eina_convert_atofp(const char *src,
int length,
Eina_F32p32 *fp) EINA_ARG_NONNULL(1, 3);
/**
* @brief Converts a string to a floating point number.
*
* @param[in] nptr a string to convert. It shouldn't be NULL.
* @param[out] endptr If @p endptr is not NULL, a pointer to the character after the last
* character used in the conversion is stored in the location referenced
* by endptr. If @p nptr is NULL, this will also be set to NULL.
* @return a double type floating point number.
*
* This function returns converted floating point number with locale-independency.
* Actually, it use "C" locale for strtod_l function internally. If you need strtod
* without locale-dependency, this function can replace strtod.
* For more information, please refer documents of strtod, strtod_l.
*/
EAPI double eina_convert_strtod_c(const char *nptr, char **endptr);
/**
* @}
*/
/**
* @}
*/
#endif /* EINA_CONVERT_H_ */