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Diffstat (limited to 'src/string_utils.h')
| -rw-r--r-- | src/string_utils.h | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/src/string_utils.h b/src/string_utils.h new file mode 100644 index 00000000..d8a0eff0 --- /dev/null +++ b/src/string_utils.h @@ -0,0 +1,163 @@ +/* + Copyright 2011-2018 David Robillard <http://drobilla.net> + + Permission to use, copy, modify, and/or distribute this software for any + purpose with or without fee is hereby granted, provided that the above + copyright notice and this permission notice appear in all copies. + + THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +*/ + +#ifndef SERD_STRING_UTILS_H +#define SERD_STRING_UTILS_H + +#include <assert.h> +#include <ctype.h> + +/** Unicode replacement character in UTF-8 */ +static const uint8_t replacement_char[] = { 0xEF, 0xBF, 0xBD }; + +/** Return true if `c` lies within [`min`...`max`] (inclusive) */ +static inline bool +in_range(const int c, const int min, const int max) +{ + return (c >= min && c <= max); +} + +/** RFC2234: ALPHA ::= %x41-5A / %x61-7A ; A-Z / a-z */ +static inline bool +is_alpha(const int c) +{ + return in_range(c, 'A', 'Z') || in_range(c, 'a', 'z'); +} + +/** RFC2234: DIGIT ::= %x30-39 ; 0-9 */ +static inline bool +is_digit(const int c) +{ + return in_range(c, '0', '9'); +} + +/* RFC2234: HEXDIG ::= DIGIT / "A" / "B" / "C" / "D" / "E" / "F" */ +static inline bool +is_hexdig(const int c) +{ + return is_digit(c) || in_range(c, 'A', 'F'); +} + +/* Turtle / JSON / C: XDIGIT ::= DIGIT / A-F / a-f */ +static inline bool +is_xdigit(const int c) +{ + return is_hexdig(c) || in_range(c, 'a', 'f'); +} + +static inline bool +is_space(const char c) +{ + switch (c) { + case ' ': case '\f': case '\n': case '\r': case '\t': case '\v': + return true; + default: + return false; + } +} + +static inline bool +is_base64(const char c) +{ + return is_alpha(c) || is_digit(c) || c == '+' || c == '/' || c == '='; +} + +static inline bool +is_windows_path(const char* path) +{ + return is_alpha(path[0]) && (path[1] == ':' || path[1] == '|') + && (path[2] == '/' || path[2] == '\\'); +} + +static inline void +serd_update_flags(const char c, SerdNodeFlags* const flags) +{ + switch (c) { + case '\r': case '\n': + *flags |= SERD_HAS_NEWLINE; + break; + case '"': + *flags |= SERD_HAS_QUOTE; + } +} + +static inline size_t +serd_substrlen(const char* const str, + const size_t len, + SerdNodeFlags* const flags) +{ + assert(flags); + + size_t i = 0; + *flags = 0; + for (; i < len && str[i]; ++i) { + serd_update_flags(str[i], flags); + } + + return i; +} + +static inline int +serd_strncasecmp(const char* s1, const char* s2, size_t n) +{ + for (; n > 0 && *s2; s1++, s2++, --n) { + if (toupper(*s1) != toupper(*s2)) { + return ((*(const uint8_t*)s1 < *(const uint8_t*)s2) ? -1 : +1); + } + } + return 0; +} + +static inline uint32_t +utf8_num_bytes(const uint8_t c) +{ + if ((c & 0x80) == 0) { // Starts with `0' + return 1; + } else if ((c & 0xE0) == 0xC0) { // Starts with `110' + return 2; + } else if ((c & 0xF0) == 0xE0) { // Starts with `1110' + return 3; + } else if ((c & 0xF8) == 0xF0) { // Starts with `11110' + return 4; + } + return 0; +} + +/// Return the code point of a UTF-8 character with known length +static inline uint32_t +parse_counted_utf8_char(const uint8_t* utf8, size_t size) +{ + uint32_t c = utf8[0] & ((1 << (8 - size)) - 1); + for (size_t i = 1; i < size; ++i) { + const uint8_t in = utf8[i] & 0x3F; + c = (c << 6) | in; + } + return c; +} + +/// Parse a UTF-8 character, set *size to the length, and return the code point +static inline uint32_t +parse_utf8_char(const uint8_t* utf8, size_t* size) +{ + switch (*size = utf8_num_bytes(utf8[0])) { + case 1: case 2: case 3: case 4: + return parse_counted_utf8_char(utf8, *size); + default: + return *size = 0; + } +} + +#endif // SERD_STRING_UTILS_H |