1 files changed, 228 insertions, 0 deletions
diff --git a/text-motions.c b/text-motions.c
new file mode 100644
index 0000000..1313c94
--- /dev/null
+++ b/text-motions.c
@@ -0,0 +1,228 @@
+#include <ctype.h>
+#include "text-motions.h"
+
+// TODO: consistent usage of iterators either char or byte based where appropriate.
+
+size_t text_line_begin(Text *txt, size_t pos) {
+	char c;
+	Iterator it = text_iterator_get(txt, pos);
+	if (!text_iterator_byte_get(&it, &c))
+		return pos;
+	if (c == '\r')
+		text_iterator_byte_prev(&it, &c);
+	if (c == '\n')
+		text_iterator_byte_prev(&it, &c);
+	while (text_iterator_byte_get(&it, &c)) {
+		if (c == '\n' || c == '\r') {
+			it.pos++;
+			break;
+		}
+		text_iterator_byte_prev(&it, NULL);
+	}
+	return pos;
+}
+
+size_t text_line_start(Text *txt, size_t pos) {
+	char c;
+	Iterator it = text_iterator_get(txt, text_line_begin(txt, pos));
+	while (text_iterator_byte_get(&it, &c) && c != '\n' && isspace(c))
+		text_iterator_byte_next(&it, NULL);
+	return it.pos;
+}
+
+size_t text_line_finish(Text *txt, size_t pos) {
+	char c;
+	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));
+	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;
+}
+
+
+size_t text_word_boundry_start_next(Text *txt, size_t pos, int (*isboundry)(int)) {
+	char c;
+	Iterator it = text_iterator_get(txt, pos);
+	while (text_iterator_byte_get(&it, &c) && !isboundry(c))
+		text_iterator_byte_next(&it, NULL);
+	while (text_iterator_byte_get(&it, &c) && isboundry(c))
+		text_iterator_byte_next(&it, NULL);
+	return it.pos;
+}
+
+size_t text_word_boundry_start_prev(Text *txt, size_t pos, int (*isboundry)(int)) {
+	char c;
+	Iterator it = text_iterator_get(txt, pos);
+	while (text_iterator_byte_prev(&it, &c) && isboundry(c));
+	do pos = it.pos; while (text_iterator_char_prev(&it, &c) && !isboundry(c));
+	return pos;
+}
+ 
+size_t text_word_boundry_end_next(Text *txt, size_t pos, int (*isboundry)(int)) {
+	char c;
+	Iterator it = text_iterator_get(txt, pos);
+	while (text_iterator_char_next(&it, &c) && isboundry(c));
+	do pos = it.pos; while (text_iterator_char_next(&it, &c) && !isboundry(c));
+	return pos;
+}
+
+size_t text_word_boundry_end_prev(Text *txt, size_t pos, int (*isboundry)(int)) {
+	char c;
+	Iterator it = text_iterator_get(txt, pos);
+	while (text_iterator_byte_prev(&it, &c) && !isboundry(c));
+	while (text_iterator_char_prev(&it, &c) && isboundry(c));
+	return it.pos;
+}
+
+size_t text_word_end_next(Text *txt, size_t pos) {
+	return text_word_boundry_end_next(txt, pos, isspace);
+}
+
+size_t text_word_end_prev(Text *txt, size_t pos) {
+	return text_word_boundry_end_prev(txt, pos, isspace);
+}
+
+size_t text_word_start_next(Text *txt, size_t pos) {
+	return text_word_boundry_start_next(txt, pos, isspace);
+}
+
+size_t text_word_start_prev(Text *txt, size_t pos) {
+	return text_word_boundry_start_prev(txt, pos, isspace);
+}
+
+static size_t text_paragraph_sentence_next(Text *txt, size_t pos, bool sentence) {
+	char c;
+	bool content = false, paragraph = false;
+	Iterator it = text_iterator_get(txt, pos);
+	while (text_iterator_byte_next(&it, &c)) {
+		content |= !isspace(c);
+		if (sentence && (c == '.' || c == '?' || c == '!') && text_iterator_byte_next(&it, &c) && isspace(c)) {
+			if (c == '\n' && text_iterator_byte_next(&it, &c)) {
+				if (c == '\r')
+					text_iterator_byte_next(&it, &c);
+			} else {
+				while (text_iterator_byte_get(&it, &c) && c == ' ')
+					text_iterator_byte_next(&it, NULL);
+			}
+			break;
+		}
+		if (c == '\n' && text_iterator_byte_next(&it, &c)) {
+			if (c == '\r')
+				text_iterator_byte_next(&it, &c);
+			content |= !isspace(c);
+			if (c == '\n')
+				paragraph = true;
+		}
+		if (content && paragraph)
+			break;
+	}
+	return it.pos;
+}
+
+static size_t text_paragraph_sentence_prev(Text *txt, size_t pos, bool sentence) {
+	char prev, c;
+	bool content = false, paragraph = false;
+
+	Iterator it = text_iterator_get(txt, pos);
+	if (!text_iterator_byte_get(&it, &prev))
+		return pos;
+
+	while (text_iterator_byte_prev(&it, &c)) {
+		content |= !isspace(c) && c != '.' && c != '?' && c != '!';
+		if (sentence && content && (c == '.' || c == '?' || c == '!') && isspace(prev)) {
+			do text_iterator_byte_next(&it, NULL);
+			while (text_iterator_byte_get(&it, &c) && isspace(c));
+			break;
+		}
+		if (c == '\r')
+			text_iterator_byte_prev(&it, &c);
+		if (c == '\n' && text_iterator_byte_prev(&it, &c)) {
+			content |= !isspace(c);
+			if (c == '\r')
+				text_iterator_byte_prev(&it, &c);
+			if (c == '\n') {
+				paragraph = true;
+				if (content) {
+					do text_iterator_byte_next(&it, NULL);
+					while (text_iterator_byte_get(&it, &c) && isspace(c));
+					break;
+				}
+			}
+		}
+		if (content && paragraph) {
+			do text_iterator_byte_next(&it, NULL);
+			while (text_iterator_byte_get(&it, &c) && !isspace(c));
+			break;
+		}
+		prev = c;
+	}
+	return it.pos;
+}
+
+size_t text_sentence_next(Text *txt, size_t pos) {
+	return text_paragraph_sentence_next(txt, pos, true);
+}
+
+size_t text_sentence_prev(Text *txt, size_t pos) {
+	return text_paragraph_sentence_prev(txt, pos, true);
+}
+
+size_t text_paragraph_next(Text *txt, size_t pos) {
+	return text_paragraph_sentence_next(txt, pos, false);
+}
+
+size_t text_paragraph_prev(Text *txt, size_t pos) {
+	return text_paragraph_sentence_prev(txt, pos, false);
+}
+
+size_t text_bracket_match(Text *txt, size_t pos) {
+	int direction, count = 1;
+	char search, current, c;
+	Iterator it = text_iterator_get(txt, pos);
+	if (!text_iterator_byte_get(&it, &current))
+		return pos;
+
+	switch (current) {
+	case '(': search = ')'; direction =  1; break;
+	case ')': search = '('; direction = -1; break;
+	case '{': search = '}'; direction =  1; break;
+	case '}': search = '{'; direction = -1; break;
+	case '[': search = ']'; direction =  1; break;
+	case ']': search = '['; direction = -1; break;
+	case '<': search = '>'; direction =  1; break;
+	case '>': search = '<'; direction = -1; break;
+	// TODO: heuristic basic on neighbouring chars shared with text-object
+	case '"': search = '"'; direction =  1; break;
+	case '\'': search = '\''; direction =  1; break;
+	default: return pos;
+	}
+
+	if (direction >= 0) { /* forward search */
+		while (text_iterator_byte_next(&it, &c)) {
+			if (c == search && --count == 0) {
+				pos = it.pos;
+				break;
+			} else if (c == current) {
+				count++;
+			}
+		}
+	} else { /* backwards */
+		while (text_iterator_byte_prev(&it, &c)) {
+			if (c == search && --count == 0) {
+				pos = it.pos;
+				break;
+			} else if (c == current) {
+				count++;
+			}
+		}
+	}
+
+	return pos;
+}