tree-sitter: implement query functionality and highlighting prototype [skip.lint]

runtime/lua/vim/treesitter.lua

@@ -12,9 +12,13 @@ function Parser:parse()
   if self.valid then
     return self.tree
   end
-  self.tree = self._parser:parse_buf(self.bufnr)
+  local changes
+  self.tree, changes = self._parser:parse_buf(self.bufnr)
   self.valid = true
-  return self.tree
+  for _, cb in ipairs(self.change_cbs) do
+    cb(changes)
+  end
+  return self.tree, changes
 end
 
 function Parser:_on_lines(bufnr, _, start_row, old_stop_row, stop_row, old_byte_size)
@@ -26,17 +30,28 @@ function Parser:_on_lines(bufnr, _, start_row, old_stop_row, stop_row, old_byte_
   self.valid = false
 end
 
-local module = {
+local M = {
   add_language=vim._ts_add_language,
   inspect_language=vim._ts_inspect_language,
+  parse_query = vim._ts_parse_query,
 }
 
-function module.create_parser(bufnr, ft, id)
+setmetatable(M, {
+  __index = function (t, k)
+      if k == "TSHighlighter" then
+        t[k] = require'vim.tshighlighter'
+        return t[k]
+      end
+   end
+ })
+
+function M.create_parser(bufnr, ft, id)
   if bufnr == 0 then
     bufnr = a.nvim_get_current_buf()
   end
-  local self = setmetatable({bufnr=bufnr, valid=false}, Parser)
+  local self = setmetatable({bufnr=bufnr, lang=ft, valid=false}, Parser)
   self._parser = vim._create_ts_parser(ft)
+  self.change_cbs = {}
   self:parse()
     -- TODO(bfredl): use weakref to self, so that the parser is free'd is no plugin is
     -- using it.
@@ -55,7 +70,7 @@ function module.create_parser(bufnr, ft, id)
   return self
 end
 
-function module.get_parser(bufnr, ft)
+function M.get_parser(bufnr, ft, cb)
   if bufnr == nil or bufnr == 0 then
     bufnr = a.nvim_get_current_buf()
   end
@@ -65,9 +80,98 @@ function module.get_parser(bufnr, ft)
   local id = tostring(bufnr)..'_'..ft
 
   if parsers[id] == nil then
-    parsers[id] = module.create_parser(bufnr, ft, id)
+    parsers[id] = M.create_parser(bufnr, ft, id)
+  end
+  if cb ~= nil then
+    table.insert(parsers[id].change_cbs, cb)
   end
   return parsers[id]
 end
 
-return module
+-- query: pattern matching on trees
+-- predicate matching is implemented in lua
+local Query = {}
+Query.__index = Query
+
+function M.parse_query(lang, query)
+  local self = setmetatable({}, Query)
+  self.query = vim._ts_parse_query(lang, query)
+  self.info = self.query:inspect()
+  self.captures = self.info.captures
+  return self
+end
+
+local function get_node_text(node, bufnr)
+  local start_row, start_col, end_row, end_col = node:range()
+  if start_row ~= end_row then
+    return nil
+  end
+  local line = a.nvim_buf_get_lines(bufnr, start_row, start_row+1, true)[1]
+  return string.sub(line, start_col+1, end_col)
+end
+
+local function match_preds(match, preds, bufnr)
+  for _, pred in pairs(preds) do
+    if pred[1] == "eq?" then
+      local node = match[pred[2]]
+      local node_text = get_node_text(node, bufnr)
+
+      local str
+      if type(pred[3]) == "string" then
+        -- (eq? @aa "foo")
+        str = pred[3]
+      else
+        -- (eq? @aa @bb)
+        str = get_node_text(match[pred[3]], bufnr)
+      end
+
+      if node_text ~= str or str == nil then
+        return false
+      end
+    else
+      return false
+    end
+  end
+  return true
+end
+
+function Query:iter_captures(node, bufnr, start, stop)
+  if bufnr == 0 then
+    bufnr = vim.api.nvim_get_current_buf()
+  end
+  local raw_iter = node:_rawquery(self.query,true,start,stop)
+  local function iter()
+    local capture, captured_node, match = raw_iter()
+    if match ~= nil then
+      local preds = self.info.patterns[match.pattern]
+      local active = match_preds(match, preds, bufnr)
+      match.active = active
+      if not active then
+        return iter() -- tail call: try next match
+      end
+    end
+    return capture, captured_node
+  end
+  return iter
+end
+
+function Query:iter_matches(node, bufnr, start, stop)
+  if bufnr == 0 then
+    bufnr = vim.api.nvim_get_current_buf()
+  end
+  local raw_iter = node:_rawquery(self.query,false,start,stop)
+  local function iter()
+    local pattern, match = raw_iter()
+    if match ~= nil then
+      local preds = self.info.patterns[pattern]
+      local active = (not preds) or match_preds(match, preds, bufnr)
+      if not active then
+        return iter() -- tail call: try next match
+      end
+    end
+    return pattern, match
+  end
+  return iter
+end
+
+return M