Add example of stopping an input modifier

examples/commandParser.js

@@ -0,0 +1,26 @@
+// This is an example Input Modifier that looks for commands from the user.
+
+const modifier = (text) => {
+  let stop = false
+
+  // This matches when the user types in ":something arg1 arg2" in any of the three input formats. For example, they could
+  // type ":status" and then command would be "status" and args would be [], or they could type ":walk north" and command
+  // would be "walk" and args would be ["north"].
+  const commandMatcher = text.match(/\n? ?(?:> You |> You say "|):(\w+?)( [\w ]+)?[".]?\n?$/i)
+  if (commandMatcher) {
+    const command = commandMatcher[1]
+    const args = commandMatcher[2] ? commandMatcher[2].trim().split(' ') : []
+    state.message = `Got command '${command}' with args ${JSON.stringify(args)}`
+    stop = true
+  } else {
+    delete state.message
+  }
+
+  // You must return an object with the text property defined.
+  // If you include { stop: true } when inside of an input modifier, processing will be stopped and nothing will be
+  // sent to the AI.
+  return { text, stop }
+}
+
+// Don't modify this part
+modifier(text)