commit 617dee3e6bd47aa94b9db5d5908e79754608b29b
parent 510432bb98a62b3509b6d152cabd6995b66521bb
Author: Jon Marrs <jdmarrs@gmail.com>
Date: Wed, 13 Sep 2023 10:40:30 -0700
damus-c: remove UTF-8 punctuation from hashtags
Check for UTF-8 punctuation (such as ellipsis) in addition to regular punctuation in hashtags.
Closes: https://github.com/damus-io/damus/issues/1518
Closes: https://github.com/damus-io/damus/pull/1546
Signed-off-by: William Casarin <jb55@jb55.com>
Diffstat:
| M | damus-c/cursor.h | | | 190 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------- |
1 file changed, 167 insertions(+), 23 deletions(-)
diff --git a/damus-c/cursor.h b/damus-c/cursor.h
@@ -107,6 +107,36 @@ static inline int pull_byte(struct cursor *cursor, u8 *c)
return 1;
}
+static inline int parse_byte(struct cursor *cursor, u8 *c)
+{
+ if (unlikely(cursor->p >= cursor->end))
+ return 0;
+
+ *c = *cursor->p;
+ //cursor->p++;
+
+ return 1;
+}
+
+static inline int parse_char(struct cursor *cur, char c) {
+ if (cur->p >= cur->end)
+ return 0;
+
+ if (*cur->p == c) {
+ cur->p++;
+ return 1;
+ }
+
+ return 0;
+}
+
+static inline int peek_char(struct cursor *cur, int ind) {
+ if ((cur->p + ind < cur->start) || (cur->p + ind >= cur->end))
+ return -1;
+
+ return *(cur->p + ind);
+}
+
static inline int cursor_pull_c_str(struct cursor *cursor, const char **str)
{
*str = (const char*)cursor->p;
@@ -435,12 +465,124 @@ static inline int is_whitespace(char c) {
return c == ' ' || c == '\t' || c == '\n' || c == '\v' || c == '\f' || c == '\r';
}
+static inline int is_underscore(char c) {
+ return c == '_';
+}
+
static inline int is_utf8_byte(u8 c) {
return c & 0x80;
}
-static inline int is_right_boundary(char c) {
- return is_whitespace(c) || ispunct(c);
+static inline int parse_utf8_char(struct cursor *cursor, unsigned int *code_point, unsigned int *utf8_length)
+{
+ u8 first_byte;
+ if (!parse_byte(cursor, &first_byte))
+ return 0; // Not enough data
+
+ // Determine the number of bytes in this UTF-8 character
+ int remaining_bytes = 0;
+ if (first_byte < 0x80) {
+ *code_point = first_byte;
+ return 1;
+ } else if ((first_byte & 0xE0) == 0xC0) {
+ remaining_bytes = 1;
+ *utf8_length = remaining_bytes + 1;
+ *code_point = first_byte & 0x1F;
+ } else if ((first_byte & 0xF0) == 0xE0) {
+ remaining_bytes = 2;
+ *utf8_length = remaining_bytes + 1;
+ *code_point = first_byte & 0x0F;
+ } else if ((first_byte & 0xF8) == 0xF0) {
+ remaining_bytes = 3;
+ *utf8_length = remaining_bytes + 1;
+ *code_point = first_byte & 0x07;
+ } else {
+ remaining_bytes = 0;
+ *utf8_length = 1; // Assume 1 byte length for unrecognized UTF-8 characters
+ // TODO: We need to gracefully handle unrecognized UTF-8 characters
+ printf("Invalid UTF-8 byte: %x\n", *code_point);
+ *code_point = ((first_byte & 0xF0) << 6); // Prevent testing as punctuation
+ return 0; // Invalid first byte
+ }
+
+ // Peek at remaining bytes
+ for (int i = 0; i < remaining_bytes; ++i) {
+ signed char next_byte;
+ if ((next_byte = peek_char(cursor, i+1)) == -1) {
+ *utf8_length = 1;
+ return 0; // Not enough data
+ }
+
+ // Debugging lines
+ //printf("Cursor: %s\n", cursor->p);
+ //printf("Codepoint: %x\n", *code_point);
+ //printf("Codepoint <<6: %x\n", ((*code_point << 6) | (next_byte & 0x3F)));
+ //printf("Remaining bytes: %x\n", remaining_bytes);
+ //printf("First byte: %x\n", first_byte);
+ //printf("Next byte: %x\n", next_byte);
+ //printf("Bitwise AND result: %x\n", (next_byte & 0xC0));
+
+ if ((next_byte & 0xC0) != 0x80) {
+ *utf8_length = 1;
+ return 0; // Invalid byte in sequence
+ }
+
+ *code_point = (*code_point << 6) | (next_byte & 0x3F);
+ }
+
+ return 1;
+}
+
+/**
+ * Checks if a given Unicode code point is a punctuation character
+ *
+ * @param codepoint The Unicode code point to check. @return true if the
+ * code point is a punctuation character, false otherwise.
+ */
+static inline int is_punctuation(unsigned int codepoint) {
+
+ // Check for underscore (underscore is not treated as punctuation)
+ if (is_underscore(codepoint))
+ return 0;
+
+ // Check for ASCII punctuation
+ if (ispunct(codepoint))
+ return 1;
+
+ // Check for Unicode punctuation exceptions (punctuation allowed in hashtags)
+ if (codepoint == 0x301C || codepoint == 0xFF5E) // Japanese Wave Dash / Tilde
+ return 0;
+
+ // Check for Unicode punctuation
+ // NOTE: We may need to adjust the codepoint ranges in the future,
+ // to include/exclude certain types of Unicode characters in hashtags.
+ // Unicode Blocks Reference: https://www.compart.com/en/unicode/block
+ return (
+ // Latin-1 Supplement No-Break Space (NBSP): U+00A0
+ (codepoint == 0x00A0) ||
+
+ // Latin-1 Supplement Punctuation: U+00A1 to U+00BF
+ (codepoint >= 0x00A1 && codepoint <= 0x00BF) ||
+
+ // General Punctuation: U+2000 to U+206F
+ (codepoint >= 0x2000 && codepoint <= 0x206F) ||
+
+ // Currency Symbols: U+20A0 to U+20CF
+ (codepoint >= 0x20A0 && codepoint <= 0x20CF) ||
+
+ // Supplemental Punctuation: U+2E00 to U+2E7F
+ (codepoint >= 0x2E00 && codepoint <= 0x2E7F) ||
+
+ // CJK Symbols and Punctuation: U+3000 to U+303F
+ (codepoint >= 0x3000 && codepoint <= 0x303F) ||
+
+ // Ideographic Description Characters: U+2FF0 to U+2FFF
+ (codepoint >= 0x2FF0 && codepoint <= 0x2FFF)
+ );
+}
+
+static inline int is_right_boundary(int c) {
+ return is_whitespace(c) || is_punctuation(c);
}
static inline int is_left_boundary(char c) {
@@ -452,15 +594,36 @@ static inline int is_alphanumeric(char c) {
}
static inline int consume_until_boundary(struct cursor *cur) {
- char c;
+ unsigned int c;
+ unsigned int char_length = 1;
+ unsigned int *utf8_char_length = &char_length;
while (cur->p < cur->end) {
c = *cur->p;
+ *utf8_char_length = 1;
+
+ if (is_whitespace(c))
+ return 1;
+
+ // Need to check for UTF-8 characters, which can be multiple bytes long
+ if (is_utf8_byte(c)) {
+ if (!parse_utf8_char(cur, &c, utf8_char_length)) {
+ if (!is_right_boundary(c)){
+ // TODO: We should work towards handling all UTF-8 characters.
+ printf("Invalid UTF-8 code point: %x\n", c);
+ }
+ }
+ }
+
if (is_right_boundary(c))
return 1;
- cur->p++;
+ // Need to use a variable character byte length for UTF-8 (2-4 bytes)
+ if (cur->p + *utf8_char_length <= cur->end)
+ cur->p += *utf8_char_length;
+ else
+ cur->p++;
}
return 1;
@@ -500,23 +663,4 @@ static inline int consume_until_non_alphanumeric(struct cursor *cur, int or_end)
return or_end;
}
-static inline int parse_char(struct cursor *cur, char c) {
- if (cur->p >= cur->end)
- return 0;
-
- if (*cur->p == c) {
- cur->p++;
- return 1;
- }
-
- return 0;
-}
-
-static inline int peek_char(struct cursor *cur, int ind) {
- if ((cur->p + ind < cur->start) || (cur->p + ind >= cur->end))
- return -1;
-
- return *(cur->p + ind);
-}
-
#endif
