1 files changed, 138 insertions, 0 deletions
diff --git a/scratch/prime_prompt_cache.lua b/scratch/prime_prompt_cache.lua
new file mode 100644
index 0000000..20fb67a
--- /dev/null
+++ b/scratch/prime_prompt_cache.lua
@@ -0,0 +1,138 @@
+local log = require('telescope.log')
+
+local PromptCache = {}
+
+function getFirstByteDiffIdx(a, b)
+  local idx = 1
+  local max_idx = #a
+  while a:byte(idx) == b:byte(idx) and idx <= max_idx do
+    idx = idx + 1
+  end
+
+  return idx
+end
+
+function PromptCache:new(opts)
+  self.__index = self
+  local obj = setmetatable({
+      current_line = nil,
+      cached_results = {},
+      cache_round = 0
+  }, self)
+
+  return obj
+end
+
+function PromptCache:set_cache(prompt, item_to_cache)
+  self.results = item_to_cache
+  self:_complete(prompt)
+end
+
+function PromptCache:_complete(prompt)
+  if #prompt == 0 then
+    self:_reset()
+    return
+  end
+
+  local cached_lines = self.results
+
+  local idx = 1
+  if self.current_line ~= nil then
+    idx = getFirstByteDiffIdx(self.current_line, prompt)
+  end
+
+  -- ABC
+  -- ABDC
+  -- IDX = 3
+  -- cr = 3
+  -- diff = 1
+  local diff = #self.cached_results - (idx - 1)
+  while diff > 0 do
+    table.remove(self.cached_results)
+    diff = diff - 1
+  end
+
+  -- ABC
+  -- ADBC
+  -- diff = 2
+  for i = idx, #prompt do
+    if #self.cached_results < (#prompt - 1) then
+      local last_cache = self:get_last_cache()
+      table.insert(self.cached_results, last_cache)
+    else
+      table.insert(self.cached_results, cached_lines)
+    end
+  end
+
+  self.current_line = prompt
+end
+
+function PromptCache:start_round(cache_round)
+  self.cache_round = cache_round
+  log.trace("start_round (had this", self.results and #self.results or nil, "for past results)", self.cache_round)
+  self.results = {}
+end
+
+function PromptCache:add_to_round(cache_round, line, score)
+  if cache_round < self.cache_round or score == -1 then
+    return
+  end
+
+  table.insert(self.results, line)
+end
+
+function PromptCache:get_last_cache()
+  local last_cache = nil
+
+  for idx = 1, #self.cached_results do
+    local cache = self.cached_results[idx]
+    if cache then
+      last_cache = cache
+    end
+  end
+
+  return last_cache
+end
+
+function PromptCache:complete_round(cache_round, prompt)
+  if cache_round ~= self.cache_round then
+    return
+  end
+
+  self:_complete(prompt)
+end
+
+function PromptCache:get_cache(prompt)
+  if self.current_line == nil or #prompt == 0 then
+    return nil
+  end
+
+  local idx = getFirstByteDiffIdx(self.current_line, prompt)
+
+  if idx == 1 then
+    self:_reset()
+    return nil
+  end
+
+  -- if we are off, then we simply need to prune the cache or let complete do
+  -- that
+  local results = nil
+  repeat
+    results = self.cached_results[idx - 1]
+    idx = idx - 1
+  until idx <= 1 or results
+
+return results
+end
+
+function PromptCache:_reset()
+    self.current_line = nil
+    self.cached_results = {}
+end
+
+
+return {
+  PromptCache = PromptCache
+}
+
+