Add fuzzy git file finderZ

6 files changed, 147 insertions, 26 deletions

diff --git a/lua/telescope/builtin.lua b/lua/telescope/builtin.lua
index 7016b0a..ff5a16d 100644
--- a/lua/telescope/builtin.lua
+++ b/lua/telescope/builtin.lua
@@ -4,28 +4,36 @@ A collection of builtin pipelines for telesceope.
 Meant for both example and for easy startup.
 --]]
 
-local Finder = require('telescope.finder')
-local pickers = require('telescope.pickers')
-
 local builtin = {}
 
-builtin.rg_vimgrep = setmetatable({}, {
-  __call = function(t, ...)
-    -- builtin.rg_vimgrep("--type lua function")
-    print(t, ...)
-  end
-})
+builtin.git_files = function(_)
+  -- TODO: Auto select bottom row
+  -- TODO: filter out results when they don't match at all anymore.
+
+  local telescope = require('telescope')
+
+  local file_finder = telescope.finders.new {
+    static = true,
+
+    fn_command = function() return 'git ls-files' end,
+  }
+
+  local file_previewer = telescope.previewers.vim_buffer
 
-builtin.rg_vimgrep.finder = Finder:new {
-  fn_command = function(prompt)
-    return string.format('rg --vimgrep %s', prompt)
-  end,
+  local file_picker = telescope.pickers.new {
+    previewer = file_previewer
+  }
 
-  responsive = false
-}
+  -- local file_sorter = telescope.sorters.get_ngram_sorter()
+  -- local file_sorter = require('telescope.sorters').get_levenshtein_sorter()
+  local file_sorter = telescope.sorters.get_norcalli_sorter()
 
-builtin.rg_vimgrep.picker = pickers.new {
-}
+  file_picker:find {
+    prompt = 'Simple File',
+    finder = file_finder,
+    sorter = file_sorter,
+  }
+end
 
 
 return builtin
diff --git a/lua/telescope/init.lua b/lua/telescope/init.lua
index 75f6d38..22d3f83 100644
--- a/lua/telescope/init.lua
+++ b/lua/telescope/init.lua
@@ -8,6 +8,7 @@ local pickers = require('telescope.pickers')
 local previewers = require('telescope.previewers')
 local sorters = require('telescope.sorters')
 local state = require('telescope.state')
+local builtin = require('telescope.builtin')
 
 local telescope = {
   -- <module>.new { }
@@ -17,6 +18,8 @@ local telescope = {
   sorters = sorters,
 
   state = state,
+
+  builtin = builtin,
 }
 
 function __TelescopeOnLeave(prompt_bufnr)
diff --git a/lua/telescope/pickers.lua b/lua/telescope/pickers.lua
index f2acfac..d0785ae 100644
--- a/lua/telescope/pickers.lua
+++ b/lua/telescope/pickers.lua
@@ -148,6 +148,11 @@ function Picker:find(opts)
       function(index, line)
         local row = self.max_results - index + 1
 
+        -- If it's less than 0, then we don't need to show it at all.
+        if row < 0 then
+          return
+        end
+
         log.trace("Setting row", row, "with value", line)
         vim.api.nvim_buf_set_lines(results_bufnr, row, row + 1, false, {line})
       end
@@ -161,8 +166,17 @@ function Picker:find(opts)
       log.trace("Processing result... ", line)
 
       local sort_score = 0
+      local sort_ok
       if sorter then
-        sort_score = sorter:score(prompt, line)
+        sort_ok, sort_score = pcall(function ()
+          return sorter:score(prompt, line)
+        end)
+
+        if not sort_ok then
+          log.warn("Sorting failed with:", prompt, line, sort_score)
+          return
+        end
+
         if sort_score == -1 then
           log.trace("Filtering out result: ", line)
           return
@@ -347,7 +361,7 @@ pickers.line_manager = function(max_results, set_line)
   --        line = ...
   --        metadata ? ...
   --    }
-  local state = {}
+  local line_state = {}
 
   set_line = set_line or function() end
 
@@ -355,7 +369,7 @@ pickers.line_manager = function(max_results, set_line)
     add_result = function(self, score, line)
       score = score or 0
 
-      for index, item in ipairs(state) do
+      for index, item in ipairs(line_state) do
         if item.score > score then
           return self:insert(index, {
             score = score,
@@ -378,17 +392,17 @@ pickers.line_manager = function(max_results, set_line)
     insert = function(self, index, item)
       if item == nil then
         item = index
-        index = #state + 1
+        index = #line_state + 1
       end
 
       -- To insert something, we place at the next available index (or specified index)
       -- and then shift all the corresponding items one place.
       local next_item
       repeat
-        next_item = state[index]
+        next_item = line_state[index]
 
         set_line(index, item.line)
-        state[index] = item
+        line_state[index] = item
 
         index = index + 1
         item = next_item
@@ -396,11 +410,11 @@ pickers.line_manager = function(max_results, set_line)
     end,
 
     num_results = function()
-      return #state
+      return #line_state
     end,
 
     _get_state = function()
-      return state
+      return line_state
     end,
   }, {
     -- insert =
diff --git a/lua/telescope/previewers.lua b/lua/telescope/previewers.lua
index ee99d11..91f0060 100644
--- a/lua/telescope/previewers.lua
+++ b/lua/telescope/previewers.lua
@@ -81,7 +81,6 @@ previewers.vim_buffer_or_bat = previewers.new {
   end,
 }
 
-
 previewers.Previewer = Previewer
 
 return previewers
diff --git a/lua/telescope/sorters.lua b/lua/telescope/sorters.lua
index 0299c91..d09b53b 100644
--- a/lua/telescope/sorters.lua
+++ b/lua/telescope/sorters.lua
@@ -1,3 +1,5 @@
+local ceil = math.ceil
+
 local log = require('telescope.log')
 local util = require('telescope.utils')
 
@@ -70,4 +72,80 @@ sorters.get_levenshtein_sorter = function()
   }
 end
 
+sorters.get_norcalli_sorter = function()
+  local ngramlen = 2
+
+  local cached_ngrams = {}
+
+  local function overlapping_ngrams(s, n)
+    if cached_ngrams[s] and cached_ngrams[s][n] then
+      return cached_ngrams[s][n]
+    end
+
+    local R = {}
+    for i = 1, s:len() - n + 1 do
+      R[#R+1] = s:sub(i, i+n-1)
+    end
+
+    if not cached_ngrams[s] then
+      cached_ngrams[s] = {}
+    end
+
+    cached_ngrams[s][n] = R
+
+    return R
+  end
+
+  return Sorter:new {
+    scoring_function = function(_, prompt, line)
+      if prompt == 0 or #prompt < ngramlen then
+        return 0
+      end
+
+      local prompt_ngrams = overlapping_ngrams(prompt, ngramlen)
+
+      local prompt_lower = prompt:lower()
+      local line_lower = line:lower()
+
+      local N = #prompt
+
+      local contains_string = line_lower:find(prompt_lower, 1, true)
+
+      local consecutive_matches = 0
+      local previous_match_index = 0
+      local match_count = 0
+
+      for i = 1, #prompt_ngrams do
+        local match_start = line_lower:find(prompt_ngrams[i], 1, true)
+        if match_start then
+          match_count = match_count + 1
+          if match_start > previous_match_index then
+            consecutive_matches = consecutive_matches + 1
+          end
+
+          previous_match_index = match_start
+        end
+      end
+
+      -- TODO: Copied from ashkan.
+      local denominator = (
+        (10 * match_count / #prompt_ngrams)
+        -- biases for shorter strings
+        -- TODO(ashkan): this can bias towards repeated finds of the same
+        -- subpattern with overlapping_ngrams
+        + 3 * match_count * ngramlen / #line
+        + consecutive_matches
+        + N / (contains_string or (2 * #line))
+        -- + 30/(c1 or 2*N)
+      )
+
+      if denominator == 0 or denominator ~= denominator then
+        return -1
+      end
+
+      return 1 / denominator
+    end
+  }
+end
+
 return sorters
diff --git a/lua/tests/telescope_spec.lua b/lua/tests/telescope_spec.lua
index c671579..9960772 100644
--- a/lua/tests/telescope_spec.lua
+++ b/lua/tests/telescope_spec.lua
@@ -1,5 +1,8 @@
 require('plenary.test_harness'):setup_busted()
 
+local log = require('telescope.log')
+-- log.use_console = false
+
 local pickers = require('telescope.pickers')
 local utils = require('telescope.utils')
 
@@ -179,4 +182,20 @@ describe('Picker', function()
   end)
 end)
 
+describe('Sorters', function()
+  describe('norcalli_sorter', function()
+    it('sort matches well', function()
+      local sorter = require('telescope.sorters').get_norcalli_sorter()
+
+      local exact_match = sorter:score('hello', 'hello')
+      local no_match = sorter:score('abcdef', 'ghijkl')
+      local ok_match = sorter:score('abcdef', 'ab')
+
+      assert(exact_match < no_match)
+      assert(exact_match < ok_match)
+      assert(ok_match < no_match)
+    end)
+  end)
+end)
+