vis: implement gJ like behavior

The behavior is not exactly the same because vim preserves any
existing white spaces wihle we remove existing ones but do
not insert additional ones.

The vim behavior (essentially only deleating new lines) can be
achived using something like:

 :x/\n/d

Close #374

4 files changed, 25 insertions, 14 deletions

diff --git a/config.def.h b/config.def.h
index af5d8e3..150551b 100644
--- a/config.def.h
+++ b/config.def.h
@@ -234,7 +234,8 @@ static const KeyBinding bindings_normal[] = {
 	{ "gv",                 ACTION(SELECTION_RESTORE)                   },
 	{ "I",                  ACTION(INSERT_LINE_START)                   },
 	{ "i",                  ACTION(MODE_INSERT)                         },
-	{ "J",                  ACTION(JOIN_LINE_BELOW)                     },
+	{ "J",                  ACTION(JOIN_LINES)                          },
+	{ "gJ",                 ACTION(JOIN_LINES_TRIM)                     },
 	{ "m",                  ACTION(MARK_SET)                            },
 	{ "<M-C-j>",            ACTION(CURSORS_NEW_LINE_BELOW_LAST)         },
 	{ "<M-C-k>",            ACTION(CURSORS_NEW_LINE_ABOVE_FIRST)        },
@@ -285,6 +286,7 @@ static const KeyBinding bindings_visual[] = {
 	{ "<Escape>",           ACTION(MODE_NORMAL)                         },
 	{ "I",                  ACTION(CURSORS_NEW_LINES_BEGIN)             },
 	{ "J",                  ACTION(JOIN_LINES)                          },
+	{ "gJ",                 ACTION(JOIN_LINES_TRIM)                     },
 	{ "o",                  ACTION(SELECTION_FLIP)                      },
 	{ "r",                  ALIAS("c")                                  },
 	{ "s",                  ALIAS("c")                                  },
diff --git a/main.c b/main.c
index 26a9390..485478e 100644
--- a/main.c
+++ b/main.c
@@ -239,8 +239,8 @@ enum {
 	VIS_ACTION_INSERT_LINE_START,
 	VIS_ACTION_OPEN_LINE_ABOVE,
 	VIS_ACTION_OPEN_LINE_BELOW,
-	VIS_ACTION_JOIN_LINE_BELOW,
 	VIS_ACTION_JOIN_LINES,
+	VIS_ACTION_JOIN_LINES_TRIM,
 	VIS_ACTION_PROMPT_SHOW,
 	VIS_ACTION_REPEAT,
 	VIS_ACTION_SELECTION_FLIP,
@@ -857,15 +857,15 @@ static const KeyAction vis_action[] = {
 		"Begin a new line below the cursor",
 		openline, { .i = +1 }
 	},
-	[VIS_ACTION_JOIN_LINE_BELOW] = {
-		"join-line-below",
-		"Join line(s)",
-		join, { .i = VIS_MOVE_LINE_NEXT },
-	},
 	[VIS_ACTION_JOIN_LINES] = {
 		"join-lines",
 		"Join selected lines",
-		operator, { .i = VIS_OP_JOIN }
+		join, { .s = " " }
+	},
+	[VIS_ACTION_JOIN_LINES_TRIM] = {
+		"join-lines-trim",
+		"Join selected lines, remove white space",
+		join, { .s = "" }
 	},
 	[VIS_ACTION_PROMPT_SHOW] = {
 		"prompt-show",
@@ -1973,11 +1973,14 @@ static const char *openline(Vis *vis, const char *keys, const Arg *arg) {
 }
 
 static const char *join(Vis *vis, const char *keys, const Arg *arg) {
-	int count = vis_count_get_default(vis, 0);
-	if (count)
-		vis_count_set(vis, count-1);
-	vis_operator(vis, VIS_OP_JOIN);
-	vis_motion(vis, arg->i);
+	bool normal = (vis_mode_get(vis) == VIS_MODE_NORMAL);
+	vis_operator(vis, VIS_OP_JOIN, arg->s);
+	if (normal) {
+		int count = vis_count_get_default(vis, 0);
+		if (count)
+			vis_count_set(vis, count-1);
+		vis_motion(vis, VIS_MOVE_LINE_NEXT);
+	}
 	return keys;
 }
 
diff --git a/vis-operators.c b/vis-operators.c
index 3954920..b7b2335 100644
--- a/vis-operators.c
+++ b/vis-operators.c
@@ -193,13 +193,15 @@ static size_t op_join(Vis *vis, Text *txt, OperatorContext *c) {
 			pos = line_prev;
 	}
 
+	size_t len = c->arg->s ? strlen(c->arg->s) : 0;
+
 	do {
 		prev_pos = pos;
 		size_t end = text_line_start(txt, pos);
 		pos = text_char_next(txt, text_line_finish(txt, text_line_prev(txt, end)));
 		if (pos >= c->range.start && end > pos) {
 			text_delete(txt, pos, end - pos);
-			text_insert(txt, pos, " ", 1);
+			text_insert(txt, pos, c->arg->s, len);
 			if (!mark)
 				mark = text_mark_set(txt, pos);
 		} else {
@@ -246,6 +248,9 @@ bool vis_operator(Vis *vis, enum VisOperator id, ...) {
 		vis->action.arg.i = id;
 		id = VIS_OP_PUT_AFTER;
 		break;
+	case VIS_OP_JOIN:
+		vis->action.arg.s = va_arg(ap, char*);
+		break;
 	case VIS_OP_FILTER:
 		vis->action.arg.s = va_arg(ap, char*);
 		/* fall through */
diff --git a/vis.h b/vis.h
index 56bf17b..91f9868 100644
--- a/vis.h
+++ b/vis.h
@@ -202,6 +202,7 @@ enum VisOperator {
  * the expected varying arguments are as follows:
  *
  *  - VIS_OP_FILTER     a char pointer referring to the command to run
+ *  - VIS_OP_JOIN       a char pointer referring to the text to insert between lines
  */
 bool vis_operator(Vis*, enum VisOperator, ...);