feat: complete handling of switch case statements (#88)

_test/interface3.go

@@ -0,0 +1,31 @@
+package main
+
+import "fmt"
+
+type fii interface {
+	Hello()
+}
+
+type Boo struct {
+	Name string
+}
+
+func (b Boo) Hello() {
+	fmt.Println("Hello", b)
+	fmt.Println(b.Name)
+}
+
+func inCall(foo fii) {
+	fmt.Println("inCall")
+	foo.Hello()
+}
+
+func main() {
+	boo := Boo{"foo"}
+	inCall(boo)
+}
+
+// Output:
+// inCall
+// Hello {foo}
+// foo