refactor(options): reduce `findoption()` usage

Problem: Many places in the code use `findoption()` to access an option using its name, even if the option index is available. This is very slow because it requires looping through the options array over and over.

Solution: Use option index instead of name wherever possible. Also introduce an `OptIndex` enum which contains the index for every option as enum constants, this eliminates the need to pass static option names as strings.

1 files changed, 8 insertions, 8 deletions

diff --git a/src/nvim/quickfix.c b/src/nvim/quickfix.c
index 112f9aa35a..976b7e837d 100644
--- a/src/nvim/quickfix.c
+++ b/src/nvim/quickfix.c
@@ -3645,12 +3645,12 @@ static int qf_goto_cwindow(const qf_info_T *qi, bool resize, int sz, bool vertsp
 static void qf_set_cwindow_options(void)
 {
   // switch off 'swapfile'
-  set_option_value_give_err("swf", BOOLEAN_OPTVAL(false), OPT_LOCAL);
-  set_option_value_give_err("bt", STATIC_CSTR_AS_OPTVAL("quickfix"), OPT_LOCAL);
-  set_option_value_give_err("bh", STATIC_CSTR_AS_OPTVAL("hide"), OPT_LOCAL);
+  set_option_value_give_err(kOptSwapfile, BOOLEAN_OPTVAL(false), OPT_LOCAL);
+  set_option_value_give_err(kOptBuftype, STATIC_CSTR_AS_OPTVAL("quickfix"), OPT_LOCAL);
+  set_option_value_give_err(kOptBufhidden, STATIC_CSTR_AS_OPTVAL("hide"), OPT_LOCAL);
   RESET_BINDING(curwin);
   curwin->w_p_diff = false;
-  set_option_value_give_err("fdm", STATIC_CSTR_AS_OPTVAL("manual"), OPT_LOCAL);
+  set_option_value_give_err(kOptFoldmethod, STATIC_CSTR_AS_OPTVAL("manual"), OPT_LOCAL);
 }
 
 // Open a new quickfix or location list window, load the quickfix buffer and
@@ -4212,7 +4212,7 @@ static void qf_fill_buffer(qf_list_T *qfl, buf_T *buf, qfline_T *old_last, int q
     // resembles reading a file into a buffer, it's more logical when using
     // autocommands.
     curbuf->b_ro_locked++;
-    set_option_value_give_err("ft", STATIC_CSTR_AS_OPTVAL("qf"), OPT_LOCAL);
+    set_option_value_give_err(kOptFiletype, STATIC_CSTR_AS_OPTVAL("qf"), OPT_LOCAL);
     curbuf->b_p_ma = false;
 
     keep_filetype = true;                 // don't detect 'filetype'
@@ -5090,7 +5090,7 @@ void ex_cfile(exarg_T *eap)
     }
   }
   if (*eap->arg != NUL) {
-    set_string_option_direct("ef", -1, eap->arg, OPT_FREE, 0);
+    set_string_option_direct(kOptErrorfile, eap->arg, OPT_FREE, 0);
   }
 
   char *enc = (*curbuf->b_p_menc != NUL) ? curbuf->b_p_menc : p_menc;
@@ -7220,7 +7220,7 @@ void ex_helpgrep(exarg_T *eap)
   bool updated = false;
   // Make 'cpoptions' empty, the 'l' flag should not be used here.
   char *const save_cpo = p_cpo;
-  const bool save_cpo_allocated = is_option_allocated("cpo");
+  const bool save_cpo_allocated = (get_option(kOptCpoptions)->flags & P_ALLOCED);
   p_cpo = empty_string_option;
 
   bool new_qi = false;
@@ -7258,7 +7258,7 @@ void ex_helpgrep(exarg_T *eap)
     // Darn, some plugin changed the value.  If it's still empty it was
     // changed and restored, need to restore in the complicated way.
     if (*p_cpo == NUL) {
-      set_option_value_give_err("cpo", CSTR_AS_OPTVAL(save_cpo), 0);
+      set_option_value_give_err(kOptCpoptions, CSTR_AS_OPTVAL(save_cpo), 0);
     }
     if (save_cpo_allocated) {
       free_string_option(save_cpo);