Ivar Fatland
66 lines
1.5 KiB
C
66 lines
1.5 KiB
C
#include <stddef.h>
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#include "utf.h"
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#include "str.h"
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typedef struct Utf8Parser {
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String str;
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} Utf8Parser;
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bool Utf8ParserNextCodePoint(Utf8Parser *this, CodePoint *out_codepoint) {
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uitn8_t const flag_1_bytes = 0;
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uint8_t const mask_1_bytes = 1 << 7;
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uint8_t const flag_continuation = mask_1_bytes;
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uint8_t const mask_continuation = (1 << 7) | (1 << 6);
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uint8_t const flag_2_bytes = mask_continuation;
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uint8_t const mask_2_bytes = (1 << 7) | (1 << 6) | (1 << 5);
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uint8_t const flag_3_bytes = mask_2_bytes;
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uint8_t const mask_3_bytes = (1 << 7) | (1 << 6) | (1 << 5) | (1 << 4);
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uint8_t const flag_4_bytes = mask_3_bytes;
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uint8_t const mask_4_bytes = (1 << 7) | (1 << 6) | (1 << 5) | (1 << 4) | (1 << 3);
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if (this->str.size == 0) {
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*out_codepoint = 0;
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return false;
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}
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if ((this->str.buffer[0] & mask_1_bytes) == flag_1_bytes) {
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*out_codepoint = (CodePoint) str[0];
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bool ok = StringSub(this->str, 1, -1, &this->str);
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assert(ok && "has to be ok since the size is not 0");
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return ok;
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} else
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}
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// max must be less than or equal to the capacity of target.
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bool CodePointsFromUtf8String(
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uint8_t const *str,
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CodePoint *target,
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int max
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) {
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for (size_t i = 0; str[i] != '\0' && max > 0;) {
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if ((str[i] & mask_1_bytes) == flag_1_bytes) {
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*target = (CodePoint) str[i];
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target += 1;
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max -= 1;
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i += 1;
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} else
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if ((str[i] & mask_2_bytes) == flag_2_bytes) {
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} else
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if ((str[i] & mask_3_bytes) == flag_3_bytes) {
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} else
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if ((str[i] & mask_4_bytes) == flag_4_bytes) {
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} else {
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false;
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}
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}
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return true;
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}
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