walker: skip EmptyExpr for now

vlib/v/checker/checker.v

@@ -637,7 +637,7 @@ pub fn (mut c Checker) struct_init(mut struct_init ast.StructInit) table.Type {
 					struct_init.fields[i].expected_type = info_field.typ
 				}
 			}
-			// Check uninitialized refs
+			// Check uninitialized refs/sum types
 			for field in info.fields {
 				if field.has_default_expr || field.name in inited_fields {
 					continue
@@ -646,6 +646,14 @@ pub fn (mut c Checker) struct_init(mut struct_init ast.StructInit) table.Type {
 					c.error('reference field `${type_sym.name}.$field.name` must be initialized',
 						struct_init.pos)
 				}
+				// Do not allow empty uninitialized sum types
+				/*
+				sym := c.table.get_type_symbol(field.typ)
+				if sym.kind == .sum_type {
+					c.warn('sum type field `${type_sym.name}.$field.name` must be initialized',
+						struct_init.pos)
+				}
+				*/
 				// Check for `[required]` struct attr
 				if field.attrs.contains('required') && !struct_init.is_short {
 					mut found := false

vlib/v/markused/walker.v

@@ -155,7 +155,8 @@ fn (mut w Walker) exprs(exprs []ast.Expr) {
 fn (mut w Walker) expr(node ast.Expr) {
 	match mut node {
 		ast.EmptyExpr {
-			panic('Walker: EmptyExpr')
+			// TODO make sure this doesn't happen
+			// panic('Walker: EmptyExpr')
 		}
 		ast.AnonFn {
 			w.fn_decl(mut node.decl)

vlib/v/table/table.v

@@ -247,7 +247,9 @@ fn (t &Table) register_aggregate_field(mut sym TypeSymbol, name string) ?Field {
 	mut agg_info := sym.info as Aggregate
 	// an aggregate always has at least 2 types
 	mut found_once := false
-	mut new_field := Field{}
+	mut new_field := Field{
+		// default_expr: ast.empty_expr()
+	}
 	for typ in agg_info.types {
 		ts := t.get_type_symbol(typ)
 		if type_field := t.find_field(ts, name) {