Analyzer does light upward type inference for location expressions

analyzer/assignment_test.go

@@ -155,6 +155,17 @@ Bird: ([fly distance:F64] [land])
 `)
 }
 
+func TestAssignmentLiteralErrDerefByteFloat (test *testing.T) {
+testStringErr (test,
+"cannot use float literal as Byte", 4, 17,
+`
+[main] = {
+	buffer:8:Byte
+	[. buffer 7] = 0.0
+}
+`)
+}
+
 func TestAssignmentLiteral (test *testing.T) {
 testString (test,
 `
@@ -175,6 +186,9 @@ testString (test,
 	struct:(x:Int y:Int) = (
 		x: 9
 		y: 10)
+
+	[.[.arr 1] 0] = 6
+	[.slice 4] = 5
 }
 `)
 }

analyzer/expression.go

@@ -184,6 +184,13 @@ func (this *Tree) analyzeSubscript (
 	if err != nil { return nil, err }
 	subscript.Offset = offset
 
+	if subscript.Ty == nil {
+		switch ty := subscript.Slice.Type().(type) {
+		case *entity.TypeSlice: subscript.Ty = ty.Element
+		case *entity.TypeArray: subscript.Ty = ty.Element
+		}
+	}
+
 	return subscript, nil
 }
 
@@ -235,7 +242,13 @@ func (this *Tree) analyzeDereference (
 	if err != nil { return nil, err }
 	dereference.Pointer = pointer
 	dereference.Ty      = into
-
+	
+	if dereference.Ty == nil {
+		switch ty := dereference.Pointer.Type().(type) {
+		case *entity.TypePointer: dereference.Ty = ty.Referenced
+		}
+	}
+	
 	return dereference, nil
 }