Bastic value type casting. (0.12.0)

examples/cast_demo.fun

@@ -0,0 +1,54 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://hanez.org/project/fun/
+ *
+ * Copyright 2025 Johannes Findeisen
+ * Licensed under the terms of the ISC license.
+ *
+ * Added: 2025-09-29
+ */
+
+print("=== CAST demo ===")
+
+// Number: parse decimal strings; invalid -> 0
+print(cast("123", "Number"))     // -> 123
+print(cast("12x", "Number"))     // -> 0
+print(cast(42, "Number"))        // -> 42
+
+// String: stringify any value
+print(cast(100, "String"))       // -> "100"
+print(typeof(cast(100, "String"))) // -> "String"
+
+// Boolean: 0 -> 0, non-zero -> 1
+print(cast(0, "Boolean"))        // -> 0
+print(cast(42, "Boolean"))       // -> 1
+
+// Array: arrays stay arrays; others get wrapped as single-element arrays
+a = cast(42, "Array")
+print(typeof(a))                  // -> "Array"
+print(len(a))                     // -> 1
+print(a[0])                       // -> 42
+
+// Map: maps stay maps; others become empty maps
+m = cast(42, "Map")
+print(typeof(m))                  // -> "Map"
+// Expect zero keys for a fresh empty map
+print(len(keys(m)))               // -> 0
+
+// Nil: always Nil
+n = cast("x", "Nil")
+print(typeof(n))                  // -> "Nil"
+
+// Function: functions stay functions; others -> Nil
+fun foo()
+  return 7
+
+print(typeof(cast(foo, "Function")))  // -> "Function"
+print(typeof(cast(42, "Function")))   // -> "Nil"
+
+// Chaining casts
+print(cast(cast("42", "Number"), "String"))  // -> "42"
+
+print("=== Done ===")