If statement expression

test/src/main.ms

@@ -3,5 +3,20 @@ package main;
 import "fmt";
 
 function main() {
+    doSomething();
+    let a = doSomethingElse();
+
+    if (a + 1 == 67 + 1) {
+        fmt.println(a);
+    }
+}
+
+function doSomething() {
     fmt.println("hello");
 }
+
+function doSomethingElse(): int {
+    fmt.println("world");
+
+    return 67;
+}