1 files changed, 60 insertions, 0 deletions
diff --git a/src/create_nvcmdidxs.vim b/src/create_nvcmdidxs.vim
new file mode 100644
index 0000000..1319276
--- /dev/null
+++ b/src/create_nvcmdidxs.vim
@@ -0,0 +1,60 @@
+" This script generates the table nv_cmd_idx[] which contains the index in
+" nv_cmds[] table (normal.c) for each of the command character supported in
+" normal/visual mode.
+" This is used to speed up the command lookup in nv_cmds[].
+"
+" Script should be run using "make nvcmdidxs", every time the nv_cmds[] table
+" in src/nv_cmds.h changes.
+"
+" This is written in legacy Vim script so that it can be run by a slightly
+" older Vim version.
+
+" Generate the table of normal/visual mode command characters and their
+" corresponding index.
+let cmd = 'create_nvcmdidxs'
+if has('unix')
+  let cmd = './' .. cmd
+endif
+let nv_cmdtbl = systemlist(cmd)->map({i, ch -> {'idx': i, 'cmdchar': ch}})
+
+" sort the table by the command character
+call sort(nv_cmdtbl, {a, b -> a.cmdchar - b.cmdchar})
+
+" Compute the highest index upto which the command character can be directly
+" used as an index.
+let nv_max_linear = 0
+for i in range(nv_cmdtbl->len())
+  if i != nv_cmdtbl[i].cmdchar
+    let nv_max_linear = i - 1
+    break
+  endif
+endfor
+
+" Generate a header file with the table
+let output =<< trim END
+  /*
+   * Automatically generated code by the create_nvcmdidxs.vim script.
+   *
+   * Table giving the index in nv_cmds[] to lookup based on
+   * the command character.
+   */
+
+  // nv_cmd_idx[<normal mode command character>] => nv_cmds[] index
+  static const unsigned short nv_cmd_idx[] =
+  {
+END
+
+" Add each command character in comment and the corresponding index
+let output += nv_cmdtbl->map({_, v ->
+      \ printf('  /* %5d */ %3d,', v.cmdchar, v.idx)})
+
+let output += ['};', '',
+      \ '// The highest index for which',
+      \ '// nv_cmds[idx].cmd_char == nv_cmd_idx[nv_cmds[idx].cmd_char]']
+
+let output += ['static const int nv_max_linear = ' .. nv_max_linear .. ';']
+
+call writefile(output, "nv_cmdidxs.h")
+quit
+
+" vim: shiftwidth=2 sts=2 expandtab