Add support for parameterized record key desugaring

Author: LPTK

hkmc2/shared/src/main/scala/hkmc2/semantics/Elaborator.scala

@@ -989,25 +989,30 @@ extends Importer with ucs.SplitElaborator:
         go(sts, Nil, RcdSpread(term(body)) :: acc)
       case InfixApp(lhs, Keywrd(Keyword.`:`), rhs) :: sts =>
         var newCtx = ctx
-        val rhs_t = rhs match
-          case _: Under => subterm(rhs)
-          case _ => term(rhs)
-        val newAcc = lhs match
+        val (rlhs, rhs_t) = rhs match
+          case _: Under => (lhs, subterm(rhs))
+          case _ =>
+            lhs match
+            case Apps(base, tups) =>
+              val rrhs = tups.foldRight(rhs):
+                InfixApp(_, Keywrd(Keyword.`=>`), _)
+              (base, term(rrhs))
+        val newAcc = rlhs match
           case id: Ident =>
             val sym = new VarSymbol(id)
             newCtx += id.name -> sym
-            RcdField(Term.Lit(StrLit(id.name)).withLocOf(id), sym.ref(id)) ::
-            DefineVar(sym, rhs_t) ::
-            LetDecl(sym, annotations) ::
-            acc
+            RcdField(Term.Lit(StrLit(id.name)).withLocOf(id), sym.ref(id))
+              :: DefineVar(sym, rhs_t)
+              :: LetDecl(sym, annotations)
+              :: acc
           case lit: Literal =>
             reportUnusedAnnotations
             RcdField(Term.Lit(lit).withLocOf(lit), rhs_t) :: acc
           case Bra(Round, inner) =>
             reportUnusedAnnotations
             RcdField(term(inner), rhs_t) :: acc
           case _ =>
-            raise(ErrorReport(msg"Unexpected record key shape." -> lhs.toLoc :: Nil))
+            raise(ErrorReport(msg"Unexpected record key shape." -> rlhs.toLoc :: Nil))
             RcdField(Term.Error, rhs_t) :: acc
         newCtx.givenIn:
           go(sts, Nil, newAcc)

hkmc2/shared/src/test/mlscript/basics/Records.mls

@@ -121,6 +121,28 @@ id of { x: 1, y: 2 }
 //│ = {x: 1, y: 2}
 
 
+let m0 = {get(k): k + 1}
+//│ m0 = {get: fun get}
+
+m0.get(41)
+//│ = 42
+
+
+let m0 = {("get")(k): k + 1}
+//│ m0 = {get: fun}
+
+m0.get(41)
+//│ = 42
+
+
+:e
+{get(k): _}
+//│ ╔══[ERROR] Unexpected record key shape.
+//│ ║  l.139: 	{get(k): _}
+//│ ╙──       	 ^^^^^^
+//│ = fun
+
+
 
 :silent
 import "../../mlscript-compile/Iter.mls"
@@ -171,14 +193,14 @@ display(x: 88, y: 99, i: 0)
 :todo
 t("group")
 //│ ╔══[ERROR] Expected 2 arguments, got 1
-//│ ║  l.172: 	t("group")
+//│ ║  l.194: 	t("group")
 //│ ╙──       	 ^^^^^^^^^
 //│ ═══[RUNTIME ERROR] Error: Function 't' expected 2 arguments but got 1
 
 :todo
 t("group")
 //│ ╔══[ERROR] Expected 2 arguments, got 1
-//│ ║  l.179: 	t("group")
+//│ ║  l.201: 	t("group")
 //│ ╙──       	 ^^^^^^^^^
 //│ ═══[RUNTIME ERROR] Error: Function 't' expected 2 arguments but got 1