54 lines
1.4 KiB
Standard ML
Executable file
54 lines
1.4 KiB
Standard ML
Executable file
#!/usr/bin/env fun
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/*
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* This file is part of the Fun programming language.
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* https://fun-lang.xyz/
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*
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* Copyright 2025 Johannes Findeisen
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* Licensed under the terms of the Apache-2.0 license.
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*
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* Added: 2025-09-29
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*/
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print("=== CAST demo ===")
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// Number: parse decimal strings; invalid -> 0
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print(cast("123", "Number")) // -> 123
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print(cast("12x", "Number")) // -> 0
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print(cast(42, "Number")) // -> 42
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// String: stringify any value
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print(cast(100, "String")) // -> "100"
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print(typeof(cast(100, "String"))) // -> "String"
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// Boolean: 0 -> 0, non-zero -> 1
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print(cast(0, "Boolean")) // -> 0
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print(cast(42, "Boolean")) // -> 1
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// Array: arrays stay arrays; others get wrapped as single-element arrays
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a = cast(42, "Array")
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print(typeof(a)) // -> "Array"
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print(len(a)) // -> 1
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print(a[0]) // -> 42
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// Map: maps stay maps; others become empty maps
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m = cast(42, "Map")
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print(typeof(m)) // -> "Map"
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// Expect zero keys for a fresh empty map
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print(len(keys(m))) // -> 0
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// Nil: always Nil
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n = cast("x", "Nil")
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print(typeof(n)) // -> "Nil"
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// Function: functions stay functions; others -> Nil
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fun foo()
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return 7
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print(typeof(cast(foo, "Function"))) // -> "Function"
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print(typeof(cast(42, "Function"))) // -> "Nil"
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// Chaining casts
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print(cast(cast("42", "Number"), "String")) // -> "42"
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print("=== Done ===")
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