diff options
Diffstat (limited to 'lib/libc/locale/wcstod.c')
-rw-r--r-- | lib/libc/locale/wcstod.c | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/lib/libc/locale/wcstod.c b/lib/libc/locale/wcstod.c new file mode 100644 index 0000000..51d8727 --- /dev/null +++ b/lib/libc/locale/wcstod.c @@ -0,0 +1,105 @@ +/*- + * Copyright (c) 2002 Tim J. Robbins + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <stdlib.h> +#include <wchar.h> +#include <wctype.h> + +/* + * Convert a string to a double-precision number. + * + * This is the wide-character counterpart of strtod(). So that we do not + * have to duplicate the code of strtod() here, we convert the supplied + * wide character string to multibyte and call strtod() on the result. + * This assumes that the multibyte encoding is compatible with ASCII + * for at least the digits, radix character and letters. + */ +double +wcstod(const wchar_t * __restrict nptr, wchar_t ** __restrict endptr) +{ + static const mbstate_t initial; + mbstate_t state; + double val; + char *buf, *end; + const wchar_t *wcp; + size_t clen, len; + + while (iswspace(*nptr)) + nptr++; + + /* + * Convert the supplied numeric wide char. string to multibyte. + * + * We could attempt to find the end of the numeric portion of the + * wide char. string to avoid converting unneeded characters but + * choose not to bother; optimising the uncommon case where + * the input string contains a lot of text after the number + * duplicates a lot of strtod()'s functionality and slows down the + * most common cases. + */ + state = initial; + wcp = nptr; + if ((len = wcsrtombs(NULL, &wcp, 0, &state)) == (size_t)-1) { + if (endptr != NULL) + *endptr = (wchar_t *)nptr; + return (0.0); + } + if ((buf = malloc(len + 1)) == NULL) + return (0.0); + state = initial; + wcsrtombs(buf, &wcp, len + 1, &state); + + /* Let strtod() do most of the work for us. */ + val = strtod(buf, &end); + + /* + * We only know where the number ended in the _multibyte_ + * representation of the string. If the caller wants to know + * where it ended, count multibyte characters to find the + * corresponding position in the wide char string. + */ + if (endptr != NULL) { +#if 1 /* Fast, assume 1:1 WC:MBS mapping. */ + *endptr = (wchar_t *)nptr + (end - buf); + (void)clen; +#else /* Slow, conservative approach. */ + state = initial; + *endptr = (wchar_t *)nptr; + while (buf < end && + (clen = mbrlen(buf, end - buf, &state)) > 0) { + buf += clen; + (*endptr)++; + } +#endif + } + + free(buf); + + return (val); +} |