feat: enabled for sources

doc/cmp.txt

@@ -540,6 +540,11 @@ sources[n].max_item_count~
   `number`
   The source-specific item count.
 
+                                          *cmp-config.sources[n].enabled*
+sources[n].enabled~
+  `boolean | fun(ctx: cmp.Source.context): boolean`
+  Whether this source should be enabled.
+
                                              *cmp-config.sources[n].group_index*
 sources[n].group_index~
   `number`

lua/cmp/source.lua

@@ -80,6 +80,19 @@ source.get_fetching_time = function(self)
   return 100 * 1000 -- return pseudo time if source isn't fetching.
 end
 
+---Return whether this source is enabled
+---@return boolean
+source.enabled = function(self)
+  local _e = self:get_source_config().enabled
+  if type(_e) == 'boolean' then
+    return _e
+  elseif type(_e) == 'function' then
+    return _e(self.context)
+  else
+    return true
+  end
+end
+
 ---Return filtered entries
 ---@param ctx cmp.Context
 ---@return cmp.Entry[]
@@ -88,6 +101,10 @@ source.get_entries = function(self, ctx)
     return {}
   end
 
+  if not self:enabled() then
+    return {}
+  end
+
   local target_entries = (function()
     local key = { 'get_entries', self.revision }
     for i = ctx.cursor.col, self.offset, -1 do

lua/cmp/types/cmp.lua

@@ -148,6 +148,7 @@ cmp.ItemField = {
 
 ---@class cmp.SourceConfig
 ---@field public name string
+---@field public enabled nil|boolean|function(ctx: cmp.Source.context): boolean
 ---@field public option table|nil
 ---@field public priority integer|nil
 ---@field public trigger_characters string[]|nil