New option: compl_data.max_list_len

doc/R.nvim.txt

@@ -1332,18 +1332,22 @@ in the Lua table `compl_data` in your `R.nvim` config. Below are the default
 values:
 >lua
     compl_data = {
+        max_list_len = 10000,
         max_depth = 3,
         max_size = 1000000,
         max_time = 100,
     },
 <
-You should increase the value of `max_depth` if you want to complete or see in
-the Object Browser more than 3 list levels. You should increase either
-`max_size` or `max_time` if `nvimcom` needs more space or more time to build
-the completion data with the desired list depth. You should decrease the
-values if you notice any delay when R is running commands. In this case,
-please, put `options(nvimcom.verbose = 1)` in your `~/.Rprofile` and use the
-information output by `nvimcom` to decide what parameter to change.
+You should increase the value of `max_list_len` if you want to be able to open in
+the Object Browser and do completion of list and S4 objects with more than
+10000 elements. You should increase the value of `max_depth` if you want to
+complete or see in the Object Browser more than 3 list levels. You should
+increase either `max_size` or `max_time` if `nvimcom` needs more space or more
+time to build the completion data with the desired list depth. You should
+decrease the values if you notice any delay when R is running commands. In
+this case, please, put `options(nvimcom.verbose = 1)` in your `~/.Rprofile`
+and use the information output by `nvimcom` to decide what parameter to
+change.
 
 It is possible to add a custom keymap through `objbr_mappings` table. The
 keymap defined in this table will be available in the object browser only.

lua/r/config.lua

@@ -166,7 +166,7 @@ local hooks = require("r.hooks")
 ---
 ---Options for fine-grained control of the object browser. Do `:help compl_data`
 ---for more information.
----@field compl_data? { max_depth: integer, max_size: integer, max_time: integer }
+---@field compl_data? { max_list_len: integer, max_depth: integer, max_size: integer, max_time: integer }
 ---
 ---Options for the r_ls (R.nvim's built-in language server)
 ---@field r_ls? RLSConfigOpts
@@ -496,6 +496,7 @@ local config = {
     convert_range_int = false,
     compldir = "",
     compl_data = {
+        max_list_len = 10000,
         max_depth = 3,
         max_size = 1000000,
         max_time = 100,

lua/r/run.lua

@@ -69,6 +69,9 @@ start_R2 = function()
         'Sys.setenv(RNVIM_ID= "' .. vim.env.RNVIM_ID .. '")',
         'Sys.setenv(RNVIM_SECRET = "' .. vim.env.RNVIM_SECRET .. '")',
         'Sys.setenv(RNVIM_PORT = "' .. vim.env.RNVIM_PORT .. '")',
+        "options(nvimcom.max_list_len = "
+            .. tostring(config.compl_data.max_list_len)
+            .. ")",
         "options(nvimcom.max_depth = " .. tostring(config.compl_data.max_depth) .. ")",
         "options(nvimcom.max_size = " .. tostring(config.compl_data.max_size) .. ")",
         "options(nvimcom.max_time = " .. tostring(config.compl_data.max_time) .. ")",

nvimcom/DESCRIPTION

@@ -1,6 +1,6 @@
 Package: nvimcom
-Version: 0.9.94
-Date: 2026-04-27
+Version: 0.9.95
+Date: 2026-06-04
 Title: Intermediate the Communication Between R and Neovim
 Authors@R: c(
     person("Jakson", "Aquino", email = "jalvesaq@gmail.com",

nvimcom/R/nvimcom.R

@@ -31,6 +31,7 @@ NvimcomEnv$tcb <- FALSE
         options(nvimcom.setwidth = TRUE)
         options(nvimcom.debug_r = TRUE)
         options(nvimcom.nvimpager = TRUE)
+        options(nvimcom.max_list_len = 10000)
         options(nvimcom.max_depth = 12)
         options(nvimcom.max_size = 1000000)
         options(nvimcom.max_time = 100)
@@ -65,6 +66,7 @@ NvimcomEnv$tcb <- FALSE
             as.integer(getOption("nvimcom.verbose")),
             as.integer(getOption("nvimcom.allnames")),
             as.integer(getOption("nvimcom.setwidth")),
+            as.integer(getOption("nvimcom.max_list_len")),
             as.integer(getOption("nvimcom.max_depth")),
             as.integer(getOption("nvimcom.max_size")),
             as.integer(getOption("nvimcom.max_time")),

nvimcom/src/nvimcom.c

@@ -93,6 +93,7 @@ static double timelimit =
     100.0; // Maximum acceptable time to build list of .GlobalEnv objects
 static int sizelimit = 1000000; // Maximum acceptable size of string
                                 // representing .GlobalEnv (list of objects)
+static int maxlslen = 10000;    // Maximum acceptable list length
 static int maxdepth = 12; // How many levels to parse in lists and S4 objects
 // when building list of objects for auto-completion. The value decreases if
 // the listing is too slow.
@@ -609,7 +610,7 @@ static char *nvimcom_glbnv_line(SEXP *x, const char *xname, const char *curenv,
 
         if (xgroup == 4 || xgroup == 7) {
             snprintf(newenv, 575, "%s%s@", curenv, xname);
-            if (len > 0) {
+            if (len > 0 && len < maxlslen) {
                 for (int i = 0; i < len; i++) {
                     ename = CHAR(STRING_ELT(sn, i));
                     if (R_has_slot(*x, Rf_install(ename)) == 1) {
@@ -627,7 +628,7 @@ static char *nvimcom_glbnv_line(SEXP *x, const char *xname, const char *curenv,
             len = length(listNames);
             if (len == 0) { /* Empty list? */
                 int len1 = length(*x);
-                if (len1 > 0) { /* List without names */
+                if (len1 > 0 && len1 < maxlslen) { /* List without names */
                     len1 -= 1;
                     if (newenv[strlen(newenv) - 1] == '$')
                         newenv[strlen(newenv) - 1] = 0; // Delete trailing '$'
@@ -643,28 +644,31 @@ static char *nvimcom_glbnv_line(SEXP *x, const char *xname, const char *curenv,
                     UNPROTECT(1);
                 }
             } else { /* Named list */
-                SEXP eexp;
-                len -= 1;
-                for (int i = 0; i < len; i++) {
-                    PROTECT(eexp = STRING_ELT(listNames, i));
-                    ename = CHAR(eexp);
-                    UNPROTECT(1);
+                if (len < maxlslen) {
+                    SEXP eexp;
+                    len -= 1;
+                    for (int i = 0; i < len; i++) {
+                        PROTECT(eexp = STRING_ELT(listNames, i));
+                        ename = CHAR(eexp);
+                        UNPROTECT(1);
+                        if (ename[0] == 0) {
+                            snprintf(ebuf, 63, "[[%d]]", i + 1);
+                            ename = ebuf;
+                        }
+                        PROTECT(elmt = VECTOR_ELT(*x, i));
+                        p = nvimcom_glbnv_line(&elmt, ename, newenv, p,
+                                               depth + 1);
+                        UNPROTECT(1);
+                    }
+                    ename = CHAR(STRING_ELT(listNames, len));
                     if (ename[0] == 0) {
-                        snprintf(ebuf, 63, "[[%d]]", i + 1);
+                        snprintf(ebuf, 63, "[[%d]]", len + 1);
                         ename = ebuf;
                     }
-                    PROTECT(elmt = VECTOR_ELT(*x, i));
+                    PROTECT(elmt = VECTOR_ELT(*x, len));
                     p = nvimcom_glbnv_line(&elmt, ename, newenv, p, depth + 1);
                     UNPROTECT(1);
                 }
-                ename = CHAR(STRING_ELT(listNames, len));
-                if (ename[0] == 0) {
-                    snprintf(ebuf, 63, "[[%d]]", len + 1);
-                    ename = ebuf;
-                }
-                PROTECT(elmt = VECTOR_ELT(*x, len));
-                p = nvimcom_glbnv_line(&elmt, ename, newenv, p, depth + 1);
-                UNPROTECT(1);
             }
             UNPROTECT(1); /* listNames */
         }
@@ -1272,11 +1276,12 @@ static void *client_loop_thread(__attribute__((unused)) void *arg)
  *
  * @param rinfo Information on R to be passed to nvim.
  */
-SEXP nvimcom_Start(SEXP vrb, SEXP anm, SEXP swd, SEXP imd, SEXP szl, SEXP tml,
-                   SEXP dbg, SEXP nvv, SEXP rinfo) {
+SEXP nvimcom_Start(SEXP vrb, SEXP anm, SEXP swd, SEXP lsl, SEXP imd, SEXP szl,
+                   SEXP tml, SEXP dbg, SEXP nvv, SEXP rinfo) {
     verbose = *INTEGER(vrb);
     allnames = *INTEGER(anm);
     setwidth = *INTEGER(swd);
+    maxlslen = *INTEGER(lsl);
     maxdepth = *INTEGER(imd);
     sizelimit = *INTEGER(szl);
     timelimit = (double)*INTEGER(tml);