option to passthrough key event to ignored buffer filetypes

doc/delaytrain.txt

@@ -45,6 +45,8 @@ following configuration (default settings included):
             ['nv'] = {'h', 'j', 'k', 'l'},
             ['nvi'] = {'<Left>', '<Down>', '<Up>', '<Right>'},
         },
+        ignore_filestypes = {}, -- Example: set to {"help", "NvimTree"} to
+                               -- disable the plugin for help and NvimTree
     }
 <
 Keep in mind that the `delay_ms` timer starts on the FIRST keypress and not the 

lua/delaytrain/init.lua

@@ -6,6 +6,7 @@ vim.g.delaytrain_grace_period = 1
 -- Map of keys to their individual current grace period
 -- This keeps track of how many times a key has been pressed
 local current_grace_period_intervals = {}
+local ignore_filetypes = {}
 
 local keymaps = {
     ['nv'] = {'h', 'j', 'k', 'l'},
@@ -14,9 +15,32 @@ local keymaps = {
 
 local is_enabled = false
 
+local function has_val(tab, val)
+    for index, value in ipairs(tab) do
+        if value == val then
+            return true
+        end
+    end
+
+    return false
+end
+
+local function sendkeys(key)
+    vim.api.nvim_feedkeys(
+    vim.api.nvim_replace_termcodes(key, true, false, true),
+    'n', 
+    false
+    )
+end
+
 function M.try_delay_keypress(key)
     current_interval = current_grace_period_intervals[key]
 
+    if has_val(ignore_filetypes, vim.o.filetype) then
+        sendkeys(key)
+        return
+    end
+
     -- Start a timer on the first keypress to reset the interval
     if current_interval == 0 then
         vim.loop.new_timer():start(vim.g.delaytrain_delay_ms, 0, function()
@@ -27,12 +51,7 @@ function M.try_delay_keypress(key)
     -- Pass the key through only if we haven't reached the grace period
     if current_interval < vim.g.delaytrain_grace_period then
         current_grace_period_intervals[key] = current_interval + 1
-
-        vim.api.nvim_feedkeys(
-        vim.api.nvim_replace_termcodes(key, true, false, true),
-        'n', 
-        false
-        )
+        sendkeys(key)
     end
 end
 
@@ -46,6 +65,8 @@ function M.setup(opts)
             vim.g.delaytrain_grace_period = opts.grace_period
         end
 
+        ignore_filetypes = vim.tbl_extend("force", ignore_filetypes, opts.ignore_filetypes)
+
         if opts.keys then
             keymaps = opts.keys
         end