var greeting = f__StringLiteral("Hello") greeting = f__add(greeting, " World!") var el = document.getElementById("welcome") el.innerHTML = greeting { action: "Concatenate String", value: "Hello World!", stack: `Error at f__add (http://localhost:1234/from.js:93754:22) at http://localhost:1234/example.js:2:12`, inputValues: [ { action: "String Literal", value: "Hello" stack: `Error at f__StringLiter