diff --git a/examples/parser.hs b/examples/parser.hs
new file mode 100644
index 0000000..cf77143
--- /dev/null
+++ b/examples/parser.hs
@@ -0,0 +1,16 @@
+data Result a = OK a String | Error String
+data Parser a = Parser (String -> Result a)
+parseBool =
+  Parser
+    (\string ->
+       case take 4 string of
+         "True" -> OK True (drop 4 string)
+         _ ->
+           case take 5 string of
+             "False" -> OK False (drop 5 string)
+             _ -> Error (append "Expected a bool, but got: " string))
+runParser =
+  \p s ->
+    case p of
+      Parser f -> f s
+main = runParser parseBool "TrueFalse"