Implement left shift operator

1 files changed, 29 insertions, 0 deletions

diff --git a/vis.c b/vis.c
index 4b9a36f..93b32b9 100644
--- a/vis.c
+++ b/vis.c
@@ -152,6 +152,7 @@ static void op_yank(OperatorContext *c);
 static void op_put(OperatorContext *c);
 static void op_delete(OperatorContext *c);
 static void op_shift_right(OperatorContext *c);
+static void op_shift_left(OperatorContext *c);
 
 /* these can be passed as int argument to operator(&(const Arg){ .i = OP_*}) */
 enum {
@@ -160,6 +161,7 @@ enum {
 	OP_YANK,
 	OP_PUT,
 	OP_SHIFT_RIGHT,
+	OP_SHIFT_LEFT,
 };
 
 static Operator ops[] = {
@@ -168,6 +170,7 @@ static Operator ops[] = {
 	[OP_YANK]   = { op_yank,   false },
 	[OP_PUT]    = { op_put,    true  },
 	[OP_SHIFT_RIGHT] = { op_shift_right, false },
+	[OP_SHIFT_LEFT]  = { op_shift_left,  false },
 };
 
 #define PAGE      INT_MAX
@@ -490,6 +493,32 @@ static void op_shift_right(OperatorContext *c) {
 	editor_draw(vis);
 }
 
+static void op_shift_left(OperatorContext *c) {
+	Text *txt = vis->win->text;
+	size_t pos = text_line_begin(txt, c->range.end), prev_pos;
+	size_t tabwidth = 8; // TODO: make configurable
+
+	/* if range ends at the begin of a line, skip line break */
+	if (pos == c->range.end)
+		pos = text_line_prev(txt, pos);
+
+	do {
+		char c;
+		size_t len = 0;
+		prev_pos = pos = text_line_begin(txt, pos);
+		Iterator it = text_iterator_get(txt, pos);
+		if (text_iterator_byte_get(&it, &c) && c == '\t') {
+			len = 1;
+		} else {
+			for (len = 0; text_iterator_byte_get(&it, &c) && c == ' '; len++)
+				text_iterator_byte_next(&it, NULL);
+		}
+		text_delete(txt, pos, MIN(len, tabwidth));
+		pos = text_line_prev(txt, pos);
+	}  while (pos >= c->range.start && pos != prev_pos);
+	editor_draw(vis);
+}
+
 /** movement implementations of type: size_t (*move)(const Arg*) */
 
 static size_t search_forward(const Arg *arg) {