relax the variable assignment match further
@@ -4,7 +4,7 @@ const EVALUATE_KEY = 13;
const NAVIGATE_UP_KEY = 38;
const NAVIGATE_DOWN_KEY = 40;
-const VARIABLE_ASSIGN_EXPR = /^\s*([a-z][a-z0-9]*)\s*=/;
+const VARIABLE_ASSIGN_EXPR = /^\s*(\S+)\s*=/;
let output = document.getElementById("output");
let inputText = document.getElementById("input-text");
