feat: add ignore_pattern option to filter language lines

lua/otter/config.lua

@@ -29,8 +29,13 @@ local default_config = {
     -- otter files are deleted on quit or main buffer close
     write_to_disk = false,
     --A table of preambles for each language. The key is the language and the value is a table of strings that will be written to the otter buffer starting on the first line.
-    preambles = {
-    }
+    preambles = {},
+    -- A table of patterns to ignore for each language. The key is the language and the value is a lua match pattern to ignore.
+    -- lua patterns: https://www.lua.org/pil/20.2.html
+    ignore_pattern = {
+      -- ipython cell magic (lines starting with %) and shell commands (lines starting with !)
+      python = "^(%s*[%%!].*)",
+    },
   },
   -- list of characters that should be stripped from the beginning and end of the code chunks
   strip_wrapping_quote_characters = { "'", '"', "`" },

lua/otter/init.lua

@@ -37,11 +37,13 @@ M.export_otter_as = keeper.export_otter_as
 ---@param diagnostics boolean? Enable diagnostics for otter buffers. Default: true
 ---@param tsquery string? Explicitly provide a treesitter query. If nil, the injections query for the current filetyepe will be used. See :h treesitter-language-injections.
 ---@paramr preambles table? A table of preambles for each language. The key is the language and the value is a table of strings that will be written to the otter buffer starting on the first line.
-M.activate = function(languages, completion, diagnostics, tsquery, preambles)
+---@paramr ignore_pattern table? A table of patterns to ignore for each language. The key is the languang and the value is a regular expression string to match patterns to ignore.
+M.activate = function(languages, completion, diagnostics, tsquery, preambles, ignore_pattern)
   languages = languages or vim.tbl_keys(require("otter.tools.extensions"))
   completion = completion ~= false
   diagnostics = diagnostics ~= false
   preambles = preambles or config.cfg.buffers.preambles
+  ignore_pattern = ignore_pattern or config.cfg.buffers.ignore_pattern
   local main_nr = api.nvim_get_current_buf()
   local main_path = api.nvim_buf_get_name(main_nr)
   local main_lang = api.nvim_get_option_value("filetype", { buf = main_nr })
@@ -74,6 +76,7 @@ M.activate = function(languages, completion, diagnostics, tsquery, preambles)
     buffers = {},
     paths = {},
     preambles = {},
+    ignore_pattern = {},
     otter_nr_to_lang = {},
     tsquery = tsquery,
     query = query,
@@ -125,6 +128,7 @@ M.activate = function(languages, completion, diagnostics, tsquery, preambles)
       keeper.rafts[main_nr].buffers[lang] = otter_nr
       keeper.rafts[main_nr].paths[lang] = otter_path
       keeper.rafts[main_nr].preambles[lang] = preambles[lang] or {}
+      keeper.rafts[main_nr].ignore_pattern[lang] = ignore_pattern[lang] or {}
       keeper.rafts[main_nr].otter_nr_to_lang[otter_nr] = lang
       table.insert(keeper.rafts[main_nr].languages, lang)
 

lua/otter/keeper.lua

@@ -16,6 +16,7 @@ local cfg = require("otter.config").cfg
 ---@field buffers table<string, integer>
 ---@field paths table<string, string>
 ---@field preambles table<string, string[]>
+---@field ignore_pattern table<string, string>
 ---@field otter_nr_to_lang table<integer, string>
 ---@field tsquery string?
 ---@field query vim.treesitter.Query
@@ -440,12 +441,18 @@ keeper.sync_raft = function(main_nr, language)
 
         -- collect language lines
         -- are allowed to overwrite the preamble
+        -- apply ignore_pattern filtering on read
+        local pattern = keeper.rafts[main_nr].ignore_pattern[lang]
         for _, t in ipairs(code_chunks) do
           local start_index = t.range["from"][1]
           for i, l in ipairs(t.text) do
             local index = start_index + i
-            table.remove(ls, index)
-            table.insert(ls, index, l)
+            if not string.match(l, pattern) then
+              table.remove(ls, index)
+              table.insert(ls, index, l)
+            else
+              table.remove(ls, index)
+            end
           end
         end