Improve text motions

2 files changed, 45 insertions, 12 deletions

diff --git a/text-motions.c b/text-motions.c
index 1313c94..8154e2b 100644
--- a/text-motions.c
+++ b/text-motions.c
@@ -1,8 +1,41 @@
 #include <ctype.h>
 #include "text-motions.h"
+#include "util.h"
 
 // TODO: consistent usage of iterators either char or byte based where appropriate.
 
+size_t text_find_char_next(Text *txt, size_t pos, const char *s, size_t len) {
+	char c;
+	size_t matched = 0;
+	Iterator it = text_iterator_get(txt, pos);
+	while (matched < len && text_iterator_byte_get(&it, &c)) {
+		if (c == s[matched])
+			matched++;
+		else
+			matched = 0;
+		text_iterator_byte_next(&it, NULL);
+	}
+	return it.pos - (matched == len ? len : 0);
+}
+
+size_t text_find_char_prev(Text *txt, size_t pos, const char *s, size_t len) {
+	char c;
+	size_t matched = len - 1;
+	Iterator it = text_iterator_get(txt, pos);
+	if (len == 0)
+		return pos;
+	while (text_iterator_byte_get(&it, &c)) {
+		if (c == s[matched]) {
+			if (matched-- == 0)
+				break;
+		} else {
+			matched = len - 1;
+		}
+		text_iterator_byte_next(&it, NULL);
+	}
+	return it.pos;
+}
+
 size_t text_line_begin(Text *txt, size_t pos) {
 	char c;
 	Iterator it = text_iterator_get(txt, pos);
@@ -19,7 +52,7 @@ size_t text_line_begin(Text *txt, size_t pos) {
 		}
 		text_iterator_byte_prev(&it, NULL);
 	}
-	return pos;
+	return it.pos;
 }
 
 size_t text_line_start(Text *txt, size_t pos) {
@@ -35,18 +68,15 @@ size_t text_line_finish(Text *txt, size_t pos) {
 	Iterator it = text_iterator_get(txt, text_line_end(txt, pos));
 	do text_iterator_byte_prev(&it, NULL);
 	while (text_iterator_byte_get(&it, &c) && c != '\n' && c != '\r' && isspace(c));
+	if (!isutf8(c))
+		text_iterator_char_prev(&it, &c);
 	return it.pos;
 }
 
 size_t text_line_end(Text *txt, size_t pos) {
-	char c;
-	Iterator it = text_iterator_get(txt, pos);
-	while (text_iterator_byte_get(&it, &c) && c != '\n')
-		text_iterator_byte_next(&it, NULL);
-	return it.pos;
+	return text_find_char_next(txt, pos, "\n", 1);
 }
 
-
 size_t text_word_boundry_start_next(Text *txt, size_t pos, int (*isboundry)(int)) {
 	char c;
 	Iterator it = text_iterator_get(txt, pos);
diff --git a/text-motions.h b/text-motions.h
index bbeca49..234376c 100644
--- a/text-motions.h
+++ b/text-motions.h
@@ -4,11 +4,14 @@
 #include <stddef.h>
 #include "text.h"
 
-/*  begin             finish
- *  v                 v
- *  |      I am a line!      |
- *         ^                 ^
- *         start             end
+size_t text_find_char_next(Text*, size_t pos, const char *s, size_t len);
+size_t text_find_char_prev(Text*, size_t pos, const char *s, size_t len);
+
+/*        begin            finish
+ *        v                v
+ *  \n[\r]      I am a line!       \n[\r]
+ *              ^                  ^
+ *              start              end
  */
 size_t text_line_begin(Text*, size_t pos);
 size_t text_line_start(Text*, size_t pos);