(renderer) invalidate cache on buffer change

lua/u/renderer.lua

@@ -373,6 +373,10 @@ function Renderer:_expr_map_callback(mode, lhs) -- {{{
 end -- }}}
 
 function Renderer:_on_text_changed()
+  -- Reset changedtick, so that the reconciler knows to refresh its cached
+  -- buffer-content before computing the diff:
+  self.changedtick = 0
+
   --- @type integer, integer
   local l, c = unpack(vim.api.nvim_win_get_cursor(0))
   l = l - 1 -- make it actually 0-based
@@ -574,13 +578,13 @@ function TreeBuilder:tree() return self.nodes end
 
 -- Levenshtein utility {{{
 -- luacheck: ignore
---- @alias LevenshteinChange<T> ({ kind: 'add'; item: T; index: number; } | { kind: 'delete'; item: T; index: number; } | { kind: 'change'; from: T; to: T; index: number; })
+--- @alias u.renderer.LevenshteinChange<T> ({ kind: 'add'; item: T; index: number; } | { kind: 'delete'; item: T; index: number; } | { kind: 'change'; from: T; to: T; index: number; })
 --- @private
 --- @generic T
 --- @param x `T`[]
 --- @param y T[]
 --- @param cost? { of_delete?: fun(x: T): number; of_add?: fun(x: T): number; of_change?: fun(x: T, y: T): number; }
---- @return LevenshteinChange<T>[] The changes, from last (greatest index) to first (smallest index).
+--- @return u.renderer.LevenshteinChange<T>[] The changes, from last (greatest index) to first (smallest index).
 function H.levenshtein(x, y, cost)
   -- At the moment, this whole `cost` plumbing is not used. Deletes have the
   -- same cost as Adds or Changes. I can imagine a future, however, where
@@ -631,7 +635,7 @@ function H.levenshtein(x, y, cost)
   -- Backtrack to find the changes
   local i = m
   local j = n
-  --- @type LevenshteinChange[]
+  --- @type u.renderer.LevenshteinChange[]
   local changes = {}
 
   while i > 0 or j > 0 do
@@ -648,7 +652,7 @@ function H.levenshtein(x, y, cost)
     if is_first_min(cost_of_change, cost_of_add, cost_of_delete) then
       -- potential change
       if x[i] ~= y[j] then
-        --- @type LevenshteinChange
+        --- @type u.renderer.LevenshteinChange
         local change = { kind = 'change', from = x[i], index = i, to = y[j] }
         table.insert(changes, change)
       end
@@ -656,13 +660,13 @@ function H.levenshtein(x, y, cost)
       j = j - 1
     elseif is_first_min(cost_of_add, cost_of_change, cost_of_delete) then
       -- addition
-      --- @type LevenshteinChange
+      --- @type u.renderer.LevenshteinChange
       local change = { kind = 'add', item = y[j], index = i + 1 }
       table.insert(changes, change)
       j = j - 1
     elseif is_first_min(cost_of_delete, cost_of_change, cost_of_add) then
       -- deletion
-      --- @type LevenshteinChange
+      --- @type u.renderer.LevenshteinChange
       local change = { kind = 'delete', item = x[i], index = i }
       table.insert(changes, change)
       i = i - 1