chore: add R and Swift syntax samples

samples/r.r

@@ -0,0 +1,21 @@
+# function declaration 
+global_function <- function(regular, named = "Hello World!") {
+  # inner function declaration
+  inner_function <- function() {
+     closure_usage <- regular
+     closure_usage + 1 
+  }
+   
+  print(named)
+  regular + inner_function()
+}
+
+# function call
+global_function(2, named = 'Hello World!')
+
+cat = list(name = "Smudge", breed = "Maine Coon")
+#variable acсess
+print(cat$breed)
+
+# namespace access
+print(datasets::cars[1, 2])

samples/swift.swift

@@ -0,0 +1,62 @@
+#!/usr/bin/swift
+/*
+ Block comment
+ */
+import Cocoa // line comment
+
+actor ActorName { var s: [StructName?] }
+struct StructName { var s: [StructName?] }
+enum EnumName { case Foo, Bar }
+protocol ProtocolName {
+  associatedtype AssociatedType
+  var p: ProtocolName { get set }
+  var prop: AssociatedType { get }
+}
+typealias TypeAlias = EnumName
+@attr(arg, *)
+class ClassName<T> : ProtocolName {
+  var property : ClassName
+  var t : T
+  func method(p: TypeAlias) {
+    let c = ClassName(),
+        tuple: (key: String, value: Int) = (key: 0, value: 1)
+    self.property = c != nil ? c! : t
+  }
+  let prop: String
+}
+
+extension ClassName { }
+extension StructName { }
+
+let i: Int = (2 + 2) * 2;
+let _ = { $0 }
+let _ = { p in p }
+let e = EnumName.Foo;
+switch e {
+  case .Foo: print("foo\n")
+  default: print("""
+      no foo \u{1F596}
+      """)
+}
+
+func function<T>(externalName paramName : T) throws {
+  func nestedFunc() { }
+  nestedFunc()
+  function(externalName: paramName + 1)
+  throw NSError()
+}
+
+#if DEBUG
+  print("debug")
+#else
+  print("nodebug")
+#endif
+#if swift(>=3.0)
+  print("conditionally not parsed code")
+#endif
+
+/// Doc comment
+/// - Parameter paramName:
+/// - Returns: value
+/// - Throws: description
+foo(paramName: Int) throws -> Int { 0 }