#965 - Make the cursor echo delay configurable

autoload/ale/cursor.vim

@@ -113,8 +113,13 @@ function! ale#cursor#EchoCursorWarningWithDelay() abort
     " we should echo something. Otherwise we can end up doing processing
     " the echo message far too frequently.
     if l:pos != s:last_pos
+        let l:delay = ale#Var(bufnr(''), 'echo_delay')
+
         let s:last_pos = l:pos
-        let s:cursor_timer = timer_start(10, function('ale#cursor#EchoCursorWarning'))
+        let s:cursor_timer = timer_start(
+        \   l:delay,
+        \   function('ale#cursor#EchoCursorWarning')
+        \)
     endif
 endfunction
 

doc/ale.txt

@@ -541,6 +541,18 @@ g:ale_echo_cursor                                           *g:ale_echo_cursor*
   The format of the message can be customizable in |g:ale_echo_msg_format|.
 
 
+g:ale_echo_delay                                             *g:ale_echo_delay*
+                                                             *b:ale_echo_delay*
+  Type: |Number|
+  Default: `10`
+
+  Given any integer, this option controls the number of milliseconds before
+  ALE will echo a message for a problem near the cursor.
+
+  The value can be increased to decrease the amount of processing ALE will do
+  for files displaying a large number of problems.
+
+
 g:ale_echo_msg_error_str                             *g:ale_echo_msg_error_str*
 
   Type: |String|

plugin/ale.vim

@@ -155,6 +155,8 @@ let g:ale_echo_msg_warning_str = get(g:, 'ale_echo_msg_warning_str', 'Warning')
 
 " This flag can be set to 0 to disable echoing when the cursor moves.
 let g:ale_echo_cursor = get(g:, 'ale_echo_cursor', 1)
+" Controls the milliseconds delay before echoing a message.
+let g:ale_echo_delay = get(g:, 'ale_echo_delay', 10)
 
 " This flag can be set to 0 to disable balloon support.
 call ale#Set('set_balloons', has('balloon_eval'))