[Feature] Add R support (#965)

ftplugin/r.lua

@@ -0,0 +1,4 @@
+require("lang.r").format()
+require("lang.r").lint()
+require("lang.r").lsp()
+require("lang.r").dap()

ftplugin/rmd.lua

@@ -0,0 +1 @@
+r.lua

lua/default-config.lua

@@ -179,6 +179,7 @@ require("lang.kotlin").config()
 require("lang.lua").config()
 require("lang.php").config()
 require("lang.python").config()
+require("lang.r").config()
 require("lang.ruby").config()
 require("lang.rust").config()
 require("lang.sh").config()

lua/lang/r.lua

@@ -0,0 +1,56 @@
+local M = {}
+
+M.config = function()
+  -- R -e 'install.packages("formatR",repos = "http://cran.us.r-project.org")'
+  -- R -e 'install.packages("readr",repos = "http://cran.us.r-project.org")'
+  O.lang.r = {
+    formatter = {
+      exe = "R",
+      args = {
+        "--slave",
+        "--no-restore",
+        "--no-save",
+        '-e "formatR::tidy_source(text=readr::read_file(file(\\"stdin\\")), arrow=FALSE)"',
+      },
+      stdin = true,
+    },
+  }
+end
+
+M.format = function()
+  O.formatters.filetype["r"] = {
+    function()
+      return {
+        exe = O.lang.r.formatter.exe,
+        args = O.lang.r.formatter.args,
+        stdin = O.lang.r.formatter.stdin,
+      }
+    end,
+  }
+  O.formatters.filetype["rmd"] = O.formatters.filetype["r"]
+
+  require("formatter.config").set_defaults {
+    logging = false,
+    filetype = O.formatters.filetype,
+  }
+end
+
+M.lint = function()
+  -- TODO: implement linters (if applicable)
+  return "No linters configured!"
+end
+
+M.lsp = function()
+  if require("lv-utils").check_lsp_client_active "r_language_server" then
+    return
+  end
+  -- R -e 'install.packages("languageserver",repos = "http://cran.us.r-project.org")'
+  require("lspconfig").r_language_server.setup {}
+end
+
+M.dap = function()
+  -- TODO: implement dap
+  return "No DAP configured!"
+end
+
+return M