Some more stdlib fun and example code and cosmetic changes. (0.38.15)

lib/utils/option.fun

@@ -0,0 +1,71 @@
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2026 Johannes Findeisen
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2026-02-19
+ */
+
+// Option helpers for ergonomic error-absent values.
+// Represented as dictionaries with a _tag and optional value field.
+
+// Constructors
+fun some(x)
+  return {"_tag": "Some", "value": x}
+
+fun none()
+  return {"_tag": "None"}
+
+// Predicates
+fun is_some(opt)
+  return opt["_tag"] == "Some"
+
+fun is_none(opt)
+  return opt["_tag"] == "None"
+
+// Extractors
+fun unwrap(opt)
+  if is_some(opt)
+    return opt["value"]
+  // Fall back to raising a runtime error
+  error("called unwrap() on None")
+  return nil
+
+fun unwrap_or(opt, default)
+  if is_some(opt)
+    return opt["value"]
+  return default
+
+// Functional helpers
+// map(opt, f) -> Some(f(value)) or None
+fun option_map(opt, f)
+  if is_some(opt)
+    return some(f(opt["value"]))
+  return none()
+
+// and_then(opt, f) where f: a -> Option[b]
+fun and_then(opt, f)
+  if is_some(opt)
+    return f(opt["value"])
+  return none()
+
+// or_else(opt, f) where f: () -> Option[a]
+fun or_else(opt, f)
+  if is_some(opt)
+    return opt
+  return f()
+
+// to_result(opt, err)
+fun to_result(opt, err)
+  if is_some(opt)
+    return ok(opt["value"])
+  return err(err)
+
+// Convenience: try_get(dict, key) -> Option[value]
+fun try_get(dict, key)
+  if has_key(dict, key)
+    return some(dict[key])
+  return none()