Add todo.scala

Author: Sporarum

tests/pos/_typeInterweaving/todo.scala

@@ -0,0 +1,66 @@
+
+
+def f1[T][U](x: T, y: U): (T, U) = (x, y)
+def f2[T](x: T)[U](y: U): (T, U) = (x, y)
+
+
+def foo[T, U][V](x: T): U = ???
+
+@main def test = foo[Int] // should probably not work (and doesn't)
+
+// check ce qui se passe quand appelée
+// def f3[T][U]: [X] => F[X]
+// done: voir higherKindedReturn.scala
+
+// reflechir quoi changer dans la spe pour rendre le currying/interweaving dans la doc
+// https://www.scala-lang.org/files/archive/spec/2.13/06-expressions.html
+//
+// Only need to change definitions, as applications can also be of that form, see higherKindedReturn.scala:11
+/* 
+ * in https://www.scala-lang.org/files/archive/spec/2.13/04-basic-declarations-and-definitions.html#function-declarations-and-definitions
+ * Change:
+ * 
+ * FunSig                 ::=  id ParamClauses
+ * ParamClauses           ::=  ParamClause {ParamClause}
+ * ParamClause            ::=  TermParamClause | TypeParamClause | UsingParamClause
+ * TermParamClause        ::=  [nl] ‘(’ [TermParams] ‘)’                              //note: allows ()
+ * TypeParamClause        ::=  [nl] ‘[’ TypeParams ‘]’
+ * UsingParamClause       ::=  [nl] ‘(’ ‘using’ TermParams ‘)’
+ * 
+ * (slightly simpler but should be equivalent to changes made in Parser.scla)
+ */
+// same for classes, je suis un peu confus par la syntaxe ci-dessous, notament Annotation et AccessModifiers, ils sont pas là en scala 3, non ?
+// https://www.scala-lang.org/files/archive/spec/2.13/05-classes-and-objects.html#class-definitions
+
+// impl param de classe, déjà Parser
+
+
+// Que faire de  TypeDcl ::=  id [TypeParamClause] {FunParamClause} TypeBounds [‘=’ Type]  //TODO: change to {ParamClauses} ?
+
+
+/* Endroits à changer: (toujour creation et application)
+    function definition     Done
+    function application    Already works
+    class definition        In Progress
+    class instantiation     Might already work
+    given definition        Todo
+    given application(?)    Doesn't exist ? or add multiple params to usings ?
+    type declarations       To be determined
+    type instantiation      Doesn't exist ?
+    extension definition    Todo   
+    extension application   Todo
+ */
+
+
+
+// étapes pour "convaincre"
+// 1) exemples simples, et exemples d'utilité
+// 2) expliquer intuitivement
+// 3) update la doc
+// 4) PR et tout le tralala
+
+
+//potentiellement cette feature en experimental
+
+// eta expension:
+val f = foo //should work and doesn't preserve type params yet