comment/uncomment selection

6 files changed, 141 insertions, 3 deletions

diff --git a/buffer.c b/buffer.c
index bdf0c01..7e59e06 100644
--- a/buffer.c
+++ b/buffer.c
@@ -137,6 +137,12 @@ static void buffer_validate_cursor(TextBuffer *buffer) {
 		buffer_pos_validate(buffer, &buffer->selection_pos);
 }
 
+// ensure *line points to a line in buffer.
+static inline void buffer_validate_line(TextBuffer *buffer, u32 *line) {
+	if (*line >= buffer->nlines)
+		*line = buffer->nlines - 1;
+}
+
 // update *pos, given that nchars characters were deleted at del_pos.
 static void buffer_pos_handle_deleted_chars(BufferPos *pos, BufferPos del_pos, u32 nchars) {
 	if (pos->line != del_pos.line) return;
@@ -2555,6 +2561,9 @@ void buffer_indent_lines(TextBuffer *buffer, u32 first_line, u32 last_line) {
 
 void buffer_dedent_lines(TextBuffer *buffer, u32 first_line, u32 last_line) {
 	assert(first_line <= last_line);
+	buffer_validate_line(buffer, &first_line);
+	buffer_validate_line(buffer, &last_line);
+	
 	buffer_start_edit_chain(buffer);
 	Settings const *settings = buffer_settings(buffer);
 	u8 const tab_width = settings->tab_width;
@@ -2583,6 +2592,7 @@ void buffer_dedent_lines(TextBuffer *buffer, u32 first_line, u32 last_line) {
 	buffer_end_edit_chain(buffer);
 }
 
+
 void buffer_indent_selection(TextBuffer *buffer) {
 	if (!buffer->selection) return;
 	u32 l1 = buffer->cursor_pos.line;
@@ -2608,3 +2618,101 @@ void buffer_dedent_cursor_line(TextBuffer *buffer) {
 	buffer_dedent_lines(buffer, line, line);
 }
 
+
+void buffer_comment_lines(TextBuffer *buffer, u32 first_line, u32 last_line) {
+	Language lang = buffer_language(buffer);
+	const char *start = language_comment_start(lang), *end = language_comment_end(lang);
+	String32 start32 = str32_from_utf8(start), end32 = str32_from_utf8(end);
+	
+	buffer_start_edit_chain(buffer);
+	
+	for (u32 line_idx = first_line; line_idx <= last_line; ++line_idx) {
+		// insert comment start
+		if (start32.len) {
+			BufferPos sol = buffer_pos_start_of_line(buffer, line_idx);
+			buffer_insert_text_at_pos(buffer, sol, start32);
+		}
+		// insert comment end
+		if (end32.len) {
+			BufferPos eol = buffer_pos_end_of_line(buffer, line_idx);
+			buffer_insert_text_at_pos(buffer, eol, end32);
+		}
+	}
+	
+	str32_free(&start32);
+	str32_free(&end32);
+	
+	buffer_end_edit_chain(buffer);
+}
+
+static bool buffer_line_starts_with_ascii(TextBuffer *buffer, u32 line_idx, char const *prefix) {
+	buffer_validate_line(buffer, &line_idx);
+	Line *line = &buffer->lines[line_idx];
+	size_t prefix_len = strlen(prefix);
+	if (line->len < prefix_len)
+		return false;
+	for (size_t i = 0; i < prefix_len; ++i) {
+		assert(prefix[i] > 0 && prefix[i] <= 127); // check if actually ASCII
+		if ((char32_t)prefix[i] != line->str[i])
+			return false;
+	}
+	return true;
+}
+static bool buffer_line_ends_with_ascii(TextBuffer *buffer, u32 line_idx, char const *suffix) {
+	buffer_validate_line(buffer, &line_idx);
+	Line *line = &buffer->lines[line_idx];
+	size_t suffix_len = strlen(suffix), line_len = line->len;
+	if (line_len < suffix_len)
+		return false;
+	for (size_t i = 0; i < suffix_len; ++i) {
+		assert(suffix[i] > 0 && suffix[i] <= 127); // check if actually ASCII
+		if ((char32_t)suffix[i] != line->str[line_len-suffix_len+i])
+			return false;
+	}
+	return true;
+}
+
+void buffer_uncomment_lines(TextBuffer *buffer, u32 first_line, u32 last_line) {
+	Language lang = buffer_language(buffer);
+	const char *start = language_comment_start(lang), *end = language_comment_end(lang);
+	u32 start_len = (u32)strlen(start), end_len = (u32)strlen(end);
+	buffer_start_edit_chain(buffer);
+	for (u32 line_idx = first_line; line_idx <= last_line; ++line_idx) {
+		// make sure line is actually commented
+		if (buffer_line_starts_with_ascii(buffer, line_idx, start)
+			&& buffer_line_ends_with_ascii(buffer, line_idx, end)) {
+			// we should do the end first, because start and end might be overlapping,
+			// and it would cause an underflow if we deleted the start first.
+			BufferPos end_pos = buffer_pos_end_of_line(buffer, line_idx);
+			end_pos.index -= end_len;
+			buffer_delete_chars_at_pos(buffer, end_pos, end_len);
+			
+			BufferPos start_pos = buffer_pos_start_of_line(buffer, line_idx);
+			buffer_delete_chars_at_pos(buffer, start_pos, start_len);
+		}
+	}
+	buffer_end_edit_chain(buffer);
+}
+
+void buffer_toggle_comment_lines(TextBuffer *buffer, u32 first_line, u32 last_line) {
+	Language lang = buffer_language(buffer);
+	const char *start = language_comment_start(lang), *end = language_comment_end(lang);
+	// if first line is a comment, uncomment lines, otherwise, comment lines
+	if (buffer_line_starts_with_ascii(buffer, first_line, start)
+		&& buffer_line_ends_with_ascii(buffer, first_line, end))
+		buffer_uncomment_lines(buffer, first_line, last_line);
+	else
+		buffer_comment_lines(buffer, first_line, last_line);
+}
+
+void buffer_toggle_comment_selection(TextBuffer *buffer) {
+	u32 l1, l2;
+	if (buffer->selection) {
+		l1 = buffer->cursor_pos.line;
+		l2 = buffer->selection_pos.line;
+		sort2_u32(&l1, &l2); // ensure l1 <= l2
+	} else {
+		l1 = l2 = buffer->cursor_pos.line;
+	}
+	buffer_toggle_comment_lines(buffer, l1, l2);
+}
diff --git a/command.c b/command.c
index e1c2ee3..c28bce5 100644
--- a/command.c
+++ b/command.c
@@ -147,6 +147,9 @@ void command_execute(Ted *ted, Command c, i64 argument) {
 			buffer_newline(buffer);
 		}
 		break;
+	case CMD_COMMENT_SELECTION:
+		if (buffer) buffer_toggle_comment_selection(buffer);
+		break;
 
 	case CMD_BACKSPACE:
 		if (buffer) buffer_backspace_at_cursor(buffer, argument);
diff --git a/command.h b/command.h
index 80bd78b..b2da2c5 100644
--- a/command.h
+++ b/command.h
@@ -32,6 +32,7 @@ ENUM_U16 {
 	CMD_BACKTAB,
 	CMD_NEWLINE, // insert '\n' + autoindent -- also used to submit line buffers
 	CMD_NEWLINE_BACK,
+	CMD_COMMENT_SELECTION,
 
 	// scrolling
 	CMD_PAGE_UP, // move cursor up one page up (where one page is however tall the buffer is)
@@ -130,6 +131,7 @@ static CommandName const command_names[] = {
 	{"backtab", CMD_BACKTAB},
 	{"newline", CMD_NEWLINE},
 	{"newline-back", CMD_NEWLINE_BACK},
+	{"comment-selection", CMD_COMMENT_SELECTION},
 	{"backspace", CMD_BACKSPACE},
 	{"delete", CMD_DELETE},
 	{"backspace-word", CMD_BACKSPACE_WORD},
diff --git a/main.c b/main.c
index 668065a..ff118cc 100644
--- a/main.c
+++ b/main.c
@@ -1,6 +1,5 @@
 // @TODO:
 // - terminate process not working on windows?
-// - comment/uncomment selection
 #include "base.h"
 no_warn_start
 #if _WIN32
diff --git a/syntax.c b/syntax.c
index 26ce234..b8efa93 100644
--- a/syntax.c
+++ b/syntax.c
@@ -13,6 +13,30 @@ Language language_from_str(char const *str) {
 	return LANG_NONE;
 }
 
+// start of single line comment for language l
+char const *language_comment_start(Language l) {
+	switch (l) {
+	case LANG_C:   return "/* ";
+	case LANG_RUST:
+	case LANG_CPP: return "// ";
+	case LANG_PYTHON: return "# ";
+	case LANG_NONE:
+	case LANG_COUNT:
+		break;
+	}
+	return "";
+}
+
+// end of single line comment for language l
+char const *language_comment_end(Language l) {
+	switch (l) {
+	case LANG_C:
+		return " */";
+	default:
+		return "";
+	}
+}
+
 // NOTE: returns the color setting, not the color
 ColorSetting syntax_char_type_to_color(SyntaxCharType t) {
 	switch (t) {
diff --git a/ted.cfg b/ted.cfg
index 96bc03b..8d6b251 100644
--- a/ted.cfg
+++ b/ted.cfg
@@ -69,6 +69,8 @@ Enter = :newline
 Shift+Enter = :newline-back
 Keypad Enter = :newline
 Shift+Keypad Enter = :newline-back
+# toggle selection between commented/uncommented
+Ctrl+/ = :comment-selection
 
 # deletion
 Delete = :delete
@@ -137,8 +139,8 @@ Ctrl+t = :generate-tags
 Ctrl+d = :goto-definition
 Ctrl+g = :goto-line
 
-Ctrl+/ = :split-horizontal
-Ctrl+Shift+/ = :split-vertical
+Ctrl+\ = :split-horizontal
+Ctrl+Shift+\ = :split-vertical
 # unsplit
 Ctrl+j = :split-join
 # switch to the other side of a split