fixes is operators for tuples (#1184)

Author: ringabout

src/nimony/sem.nim

@@ -4198,7 +4198,16 @@ proc semIs(c: var SemContext; it: var Item) =
   it.n = lhs.n
   if lhs.typ.typeKind == TypedescT:
     inc lhs.typ
-  let rhs = semLocalType(c, it.n)
+
+  let rhs: TypeCursor
+  if it.n.exprKind == TupConstrX:
+    inc it.n
+    rhs = semLocalType(c, it.n)
+    while it.n.kind != ParRi:
+      skip it.n
+    skipParRi it.n
+  else:
+    rhs = semLocalType(c, it.n)
   skipParRi it.n
   c.dest.shrink beforeExpr # delete LHS and RHS
   if containsGenericParams(lhs.typ) or containsGenericParams(rhs):

src/nimony/sigmatch.nim

@@ -957,6 +957,11 @@ proc isSomeSeqType*(a: Cursor): bool {.inline.} =
   var dummy = default(Cursor)
   result = isSomeSeqType(a, dummy)
 
+proc getTupleFieldTypeSkipTypedesc(c: Cursor): Cursor =
+  result = getTupleFieldType(c)
+  if result.typeKind == TypedescT:
+    inc result
+
 proc singleArgImpl(m: var Match; f: var Cursor; arg: CallArg) =
   case f.kind
   of Symbol:
@@ -1093,8 +1098,8 @@ proc singleArgImpl(m: var Match; f: var Cursor; arg: CallArg) =
             # len(f) > len(a)
             m.error InvalidMatch, fOrig, aOrig
           # only the type of the field is important:
-          var ffld = getTupleFieldType(f)
-          var afld = getTupleFieldType(a)
+          var ffld = getTupleFieldTypeSkipTypedesc(f)
+          var afld = getTupleFieldTypeSkipTypedesc(a)
           linearMatch m, ffld, afld
           # skip fields:
           skip f

tests/nimony/types/tisopr.nim

@@ -42,3 +42,16 @@ assert Foo[int, float] is Foo[int, float]
 assert Foo[float, float] is Foo[float, float]
 assert Foo[int, float] isnot Foo[float, float]
 assert Foo[int, int] isnot Bar[int, int]
+
+
+type
+  Person = tuple[name: string, age: int] # type representing a person:
+                                         # it consists of a name and an age.
+var person: Person
+person = (name: "Peter", age: 30)
+assert person.name == "Peter"
+# the same, but less readable:
+person = ("Peter", 30)
+assert person[0] == "Peter"
+assert Person is (string, int)
+assert (string, int) is Person