feat/refacto: improve configurations

- You should now get the configs through functions
- Configs for languages are now inside a local object called parsers
- You can get the parser installation configurations with `get_parser_configs`
- A new object has been initialized inside configs to specify module config (called config).
- Provide functions to enable/disable a module on one buffer
- Provide functions to enable/disable a module on all buffers, and if filetype is
  specified, for specific filetype
- Provide function to determine if module is activated for a specified filetype

lua/nvim-treesitter/info.lua

@@ -0,0 +1,96 @@
+local api = vim.api
+local configs = require'nvim-treesitter.configs'
+
+local M = {}
+
+local function install_info()
+  local max_len = 0
+  for _, ft in pairs(configs.available_parsers()) do
+    if #ft > max_len then max_len = #ft end
+  end
+
+  for _, ft in pairs(configs.available_parsers()) do
+    local is_installed = #api.nvim_get_runtime_file('parser/'..ft..'.so', false) > 0
+    api.nvim_out_write(ft..string.rep(' ', max_len - #ft + 1))
+    if is_installed then
+      api.nvim_out_write("[✓] installed\n")
+    else
+      api.nvim_out_write("[✗] not installed\n")
+    end
+  end
+end
+
+local function print_info_module(sorted_filetypes, mod)
+  local max_str_len = #sorted_filetypes[1]
+  local header = string.format('%s%s', string.rep(' ', max_str_len + 2), mod)
+  api.nvim_out_write(header..'\n')
+  for _, ft in pairs(sorted_filetypes) do
+    local padding = string.rep(' ', max_str_len - #ft + #mod / 2 + 1)
+    api.nvim_out_write(ft..":"..padding)
+    if configs.is_enabled(mod, ft) then
+      api.nvim_out_write('✓')
+    else
+      api.nvim_out_write('✗')
+    end
+    api.nvim_out_write('\n')
+  end
+end
+
+local function print_info_modules(sorted_filetypes)
+  local max_str_len = #sorted_filetypes[1]
+  local header = string.rep(' ', max_str_len + 2)
+  for _, mod in pairs(configs.available_modules()) do
+    header = string.format('%s%s ', header, mod)
+  end
+  api.nvim_out_write(header..'\n')
+
+  for _, ft in pairs(sorted_filetypes) do
+    local padding = string.rep(' ', max_str_len - #ft)
+    api.nvim_out_write(ft..":"..padding)
+
+    for _, mod in pairs(configs.available_modules()) do
+      local pad_len = #mod / 2 + 1
+      api.nvim_out_write(string.rep(' ', pad_len))
+
+      if configs.is_enabled(mod, ft) then
+        api.nvim_out_write('✓')
+      else
+        api.nvim_out_write('✗')
+      end
+      api.nvim_out_write(string.rep(' ', pad_len - 1))
+    end
+    api.nvim_out_write('\n')
+  end
+end
+
+local function module_info(mod)
+  if mod and not configs.get_config()[mod] then return end
+
+  local ft_by_len = configs.available_parsers()
+  table.sort(ft_by_len, function(a, b) return #a > #b end)
+  if mod then
+    print_info_module(ft_by_len, mod)
+  else
+    print_info_modules(ft_by_len)
+  end
+end
+
+M.commands = {
+  TSInstallInfo = {
+    run = install_info,
+    args = {
+      "-nargs=0",
+    },
+    description = '`:TSInstallInfo` print installation state for every filetype'
+  },
+  TSModuleInfo = {
+    run = module_info,
+    args = {
+      "-nargs=?",
+      "-complete=custom,v:lua.ts_available_modules"
+    },
+    description = '`:TSModuleInfo` print module state for every filetype, if module is specified, only for current module'
+  }
+}
+
+return M