vim-patch:9.1.0142: getregion() can be improved (#27662)

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: vim/vim#14090

https://github.com/vim/vim/commit/19b718828d8d5fab52d94c6cdba694641879ab38

Co-authored-by: Shougo Matsushita <Shougo.Matsu@gmail.com>

2 files changed, 52 insertions, 37 deletions

diff --git a/src/nvim/eval.lua b/src/nvim/eval.lua
index e03ee77141..8dc282cd43 100644
--- a/src/nvim/eval.lua
+++ b/src/nvim/eval.lua
@@ -4356,16 +4356,27 @@ M.funcs = {
     signature = 'getreginfo([{regname}])',
   },
   getregion = {
-    args = 3,
+    args = { 2, 3 },
     base = 1,
     desc = [=[
-      Returns the list of strings from {pos1} to {pos2} as if it's
-      selected in visual mode of {type}.
-      For possible values of {pos1} and {pos2} see |line()|.
-      {type} is the selection type:
-      	"v" for |charwise| mode
-      	"V" for |linewise| mode
-      	"<CTRL-V>" for |blockwise-visual| mode
+      Returns the list of strings from {pos1} to {pos2} in current
+      buffer.
+
+      {pos1} and {pos2} must both be |List|s with four numbers.
+      See |getpos()| for the format of the list.
+
+      The optional argument {opts} is a Dict and supports the
+      following items:
+
+      	type		Specify the selection type
+      			(default: "v"):
+      	    "v"		for |charwise| mode
+      	    "V"		for |linewise| mode
+      	    "<CTRL-V>"	for |blockwise-visual| mode
+
+      	exclusive	If |TRUE|, use exclusive selection
+      			for the end position 'selection'.
+
       You can get the last selection type by |visualmode()|.
       If Visual mode is active, use |mode()| to get the Visual mode
       (e.g., in a |:vmap|).
@@ -4383,22 +4394,19 @@ M.funcs = {
       - If the selection starts or ends in the middle of a multibyte
         character, it is not included but its selected part is
         substituted with spaces.
-      - If {pos1} or {pos2} equals "v" (see |line()|) and it is not in
-        |visual-mode|, an empty list is returned.
-      - If {pos1}, {pos2} or {type} is an invalid string, an empty
-        list is returned.
-      - If {pos1} or {pos2} is a mark in different buffer, an empty
+      - If {pos1} or {pos2} is not current in the buffer, an empty
         list is returned.
 
       Examples: >
       	:xnoremap <CR>
-      	\ <Cmd>echom getregion('v', '.', mode())<CR>
+      	\ <Cmd>echom getregion(
+      	\ getpos('v'), getpos('.'), #{ type: mode() })<CR>
       <
     ]=],
     name = 'getregion',
-    params = { { 'pos1', 'string' }, { 'pos2', 'string' }, { 'type', 'string' } },
+    params = { { 'pos1', 'table' }, { 'pos2', 'table' }, { 'opts', 'table' } },
     returns = 'string[]',
-    signature = 'getregion({pos1}, {pos2}, {type})',
+    signature = 'getregion({pos1}, {pos2} [, {opts}])',
   },
   getregtype = {
     args = { 0, 1 },
diff --git a/src/nvim/eval/funcs.c b/src/nvim/eval/funcs.c
index c16fc1d708..3b387e3fd6 100644
--- a/src/nvim/eval/funcs.c
+++ b/src/nvim/eval/funcs.c
@@ -2821,35 +2821,38 @@ static void f_getregion(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 {
   tv_list_alloc_ret(rettv, kListLenMayKnow);
 
-  if (tv_check_for_string_arg(argvars, 0) == FAIL
-      || tv_check_for_string_arg(argvars, 1) == FAIL
-      || tv_check_for_string_arg(argvars, 2) == FAIL) {
+  if (tv_check_for_list_arg(argvars, 0) == FAIL
+      || tv_check_for_list_arg(argvars, 1) == FAIL
+      || tv_check_for_opt_dict_arg(argvars, 2) == FAIL) {
     return;
   }
 
   int fnum = -1;
-  // NOTE: var2fpos() returns static pointer.
-  pos_T *fp = var2fpos(&argvars[0], true, &fnum, false);
-  if (fp == NULL || (fnum >= 0 && fnum != curbuf->b_fnum)) {
+  pos_T p1;
+  if (list2fpos(&argvars[0], &p1, &fnum, NULL, false) != OK
+      || (fnum >= 0 && fnum != curbuf->b_fnum)) {
     return;
   }
-  pos_T p1 = *fp;
 
-  fp = var2fpos(&argvars[1], true, &fnum, false);
-  if (fp == NULL || (fnum >= 0 && fnum != curbuf->b_fnum)) {
+  pos_T p2;
+  if (list2fpos(&argvars[1], &p2, &fnum, NULL, false) != OK
+      || (fnum >= 0 && fnum != curbuf->b_fnum)) {
     return;
   }
-  pos_T p2 = *fp;
-
-  const char *pos1 = tv_get_string(&argvars[0]);
-  const char *pos2 = tv_get_string(&argvars[1]);
-  const char *type = tv_get_string(&argvars[2]);
-
-  const bool is_visual
-    = (pos1[0] == 'v' && pos1[1] == NUL) || (pos2[0] == 'v' && pos2[1] == NUL);
 
-  if (is_visual && !VIsual_active) {
-    return;
+  bool is_select_exclusive;
+  char *type;
+  char default_type[] = "v";
+  if (argvars[2].v_type == VAR_DICT) {
+    is_select_exclusive = tv_dict_get_bool(argvars[2].vval.v_dict, "exclusive",
+                                           *p_sel == 'e');
+    type = tv_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;
   }
 
   MotionType region_type = kMTUnknown;
@@ -2866,6 +2869,10 @@ static void f_getregion(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
   const TriState save_virtual = virtual_op;
   virtual_op = virtual_active();
 
+  // NOTE: Adjust is needed.
+  p1.col--;
+  p2.col--;
+
   if (!lt(p1, p2)) {
     // swap position
     pos_T p = p1;
@@ -2878,7 +2885,7 @@ static void f_getregion(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
 
   if (region_type == kMTCharWise) {
     // handle 'selection' == "exclusive"
-    if (*p_sel == 'e' && !equalpos(p1, p2)) {
+    if (is_select_exclusive && !equalpos(p1, p2)) {
       if (p2.coladd > 0) {
         p2.coladd--;
       } else if (p2.col > 0) {
@@ -2907,7 +2914,7 @@ static void f_getregion(typval_T *argvars, typval_T *rettv, EvalFuncData fptr)
     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);