patch 9.1.0142: getregion() can be improved

Problem:  getregion() can be improved (after v9.1.120)
Solution: change getregion() implementation to use pos as lists and
          one optional {opt} dictionary (Shougo Matsushita)

Note: The following is a breaking change!

Currently, the getregion() function (included as of patch v9.1.120) takes
3 arguments: the first 2 arguments are strings, describing a position,
arg3 is the type string.

However, that is slightly inflexible, there is no way to specify
additional arguments. So let's instead change the function signature to:

getregion(pos1, pos2 [, {Dict}]) where both pos1 and pos2 are lists.
This is slightly cleaner, and gives us the flexibility to specify
additional arguments as key/value pairs to the optional Dict arg.

Now it supports the "type" key to specify the selection type
(characterwise, blockwise or linewise) and now in addition one can also
define the selection type, independently of what the 'selection' option
actually is.

Technically, this is a breaking change, but since the getregion()
Vimscript function is still quite new, this should be fine.

closes: #14090

Co-authored-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Shougo Matsushita <Shougo.Matsu@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/evalfunc.c b/src/evalfunc.c
index 37010d7..b5d8c87 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -1151,6 +1151,7 @@
 static argcheck_T arg3_dict_number_number[] = {arg_dict_any, arg_number, arg_number};
 static argcheck_T arg3_diff[] = {arg_list_string, arg_list_string, arg_dict_any};
 static argcheck_T arg3_list_string_dict[] = {arg_list_any, arg_string, arg_dict_any};
+static argcheck_T arg3_list_list_dict[] = {arg_list_any, arg_list_any, arg_dict_any};
 static argcheck_T arg3_lnum_number_bool[] = {arg_lnum, arg_number, arg_bool};
 static argcheck_T arg3_number[] = {arg_number, arg_number, arg_number};
 static argcheck_T arg3_number_any_dict[] = {arg_number, arg_any, arg_dict_any};
@@ -2132,7 +2133,7 @@
 			ret_getreg,	    f_getreg},
     {"getreginfo",	0, 1, FEARG_1,	    arg1_string,
 			ret_dict_any,	    f_getreginfo},
-    {"getregion",	3, 3, FEARG_1,	    arg3_string,
+    {"getregion",	2, 3, FEARG_1,	    arg3_list_list_dict,
 			ret_list_string,    f_getregion},
     {"getregtype",	0, 1, FEARG_1,	    arg1_string,
 			ret_string,	    f_getregtype},
@@ -5491,41 +5492,43 @@
     int			inclusive = TRUE;
     int			fnum = -1;
     pos_T		p1, p2;
-    pos_T		*fp = NULL;
-    char_u		*pos1, *pos2, *type;
+    char_u		*type;
+    char_u		default_type[] = "v";
     int			save_virtual = -1;
     int			l;
     int			region_type = -1;
-    int			is_visual;
+    int			is_select_exclusive;
 
     if (rettv_list_alloc(rettv) == FAIL)
 	return;
 
-    if (check_for_string_arg(argvars, 0) == FAIL
-	    || check_for_string_arg(argvars, 1) == FAIL
-	    || check_for_string_arg(argvars, 2) == FAIL)
+    if (check_for_list_arg(argvars, 0) == FAIL
+	    || check_for_list_arg(argvars, 1) == FAIL
+	    || check_for_opt_dict_arg(argvars, 2) == FAIL)
 	return;
 
-    // NOTE: var2fpos() returns static pointer.
-    fp = var2fpos(&argvars[0], TRUE, &fnum, FALSE);
-    if (fp == NULL || (fnum >= 0 && fnum != curbuf->b_fnum))
+    if (list2fpos(&argvars[0], &p1, &fnum, NULL, FALSE) != OK
+	    || (fnum >= 0 && fnum != curbuf->b_fnum))
 	return;
-    p1 = *fp;
 
-    fp = var2fpos(&argvars[1], TRUE, &fnum, FALSE);
-    if (fp == NULL || (fnum >= 0 && fnum != curbuf->b_fnum))
+    if (list2fpos(&argvars[1], &p2, &fnum, NULL, FALSE) != OK
+	    || (fnum >= 0 && fnum != curbuf->b_fnum))
 	return;
-    p2 = *fp;
 
-    pos1 = tv_get_string(&argvars[0]);
-    pos2 = tv_get_string(&argvars[1]);
-    type = tv_get_string(&argvars[2]);
-
-    is_visual = (pos1[0] == 'v' && pos1[1] == NUL)
-	|| (pos2[0] == 'v' && pos2[1] == NUL);
-
-    if (is_visual && !VIsual_active)
-	return;
+    if (argvars[2].v_type == VAR_DICT)
+    {
+	is_select_exclusive = dict_get_bool(
+		argvars[2].vval.v_dict, "exclusive", *p_sel == 'e');
+	type = dict_get_string(
+		argvars[2].vval.v_dict, "type", FALSE);
+	if (type == NULL)
+	    type = default_type;
+    }
+    else
+    {
+	is_select_exclusive = *p_sel == 'e';
+	type = default_type;
+    }
 
     if (type[0] == 'v' && type[1] == NUL)
 	region_type = MCHAR;
@@ -5539,6 +5542,10 @@
     save_virtual = virtual_op;
     virtual_op = virtual_active();
 
+    // NOTE: Adjust is needed.
+    p1.col--;
+    p2.col--;
+
     if (!LT_POS(p1, p2))
     {
 	// swap position
@@ -5552,7 +5559,7 @@
     if (region_type == MCHAR)
     {
 	// handle 'selection' == "exclusive"
-	if (*p_sel == 'e' && !EQUAL_POS(p1, p2))
+	if (is_select_exclusive && !EQUAL_POS(p1, p2))
 	{
 	    if (p2.coladd > 0)
 		p2.coladd--;
@@ -5590,7 +5597,7 @@
 	oa.start = p1;
 	oa.end = p2;
 	oa.start_vcol = MIN(sc1, sc2);
-	if (*p_sel == 'e' && ec1 < sc2 && 0 < sc2 && ec2 > ec1)
+	if (is_select_exclusive && ec1 < sc2 && 0 < sc2 && ec2 > ec1)
 	    oa.end_vcol = sc2 - 1;
 	else
 	    oa.end_vcol = MAX(ec1, ec2);