[playground] New default program

playground/knot/src/Playground.tsx

@@ -205,9 +205,31 @@ export const DEFAULT_SETTINGS = JSON.stringify(
   4,
 );
 
+const DEFAULT_PROGRAM = `from typing import Literal
+
+type Style = Literal["italic", "bold", "underline"]
+
+# Add parameter annotations \`line: str, word: str, style: Style\` and a return
+# type annotation \`-> str\` to see if you can find the mistakes in this program.
+
+def with_style(line, word, style):
+    if style == "italic":
+        return line.replace(word, f"*{word}*")
+    elif style == "bold":
+        return line.replace(word, f"__{word}__")
+
+    position = line.find(word)
+    output = line + "\\n"
+    output += " " * position
+    output += "-" * len(word)
+
+
+print(with_style("Red Knot is a fast type checker for Python.", "fast", "underlined"))
+`;
+
 const DEFAULT_WORKSPACE = {
   files: {
-    "main.py": "import os",
+    "main.py": DEFAULT_PROGRAM,
     "knot.json": DEFAULT_SETTINGS,
   },
   current: "main.py",