Brandon Lucas
0b5abece5f
Standard examples (examples/standard/): - hello_world: Basic effect usage - fizzbuzz: Classic programming exercise - factorial: Recursive and tail-recursive versions - primes: Prime number generation - guessing_game: Interactive Random + Console effects - stdlib_demo: Demonstrates List, String, Option, Math modules Showcase examples (examples/showcase/): - ask_pattern: Resumable effects for config/environment - custom_logging: Custom effect with handler - early_return: Fail effect for clean error handling - effect_composition: Combining multiple effects - higher_order: Closures and function composition - pattern_matching: ADTs and exhaustive matching Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
40 lines
1.0 KiB
Plaintext
40 lines
1.0 KiB
Plaintext
// Early Return with Fail Effect
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//
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// The Fail effect provides clean early termination.
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// Functions declare their failure modes in the type signature.
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//
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// Expected output:
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// Parsing "42"...
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// Result: 42
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// Parsing "100"...
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// Result: 100
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// Dividing 100 by 4...
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// Result: 25
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fn parsePositive(s: String): Int with {Fail, Console} = {
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Console.print("Parsing \"" + s + "\"...")
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if s == "42" then 42
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else if s == "100" then 100
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else Fail.fail("Invalid number: " + s)
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}
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fn safeDivide(a: Int, b: Int): Int with {Fail, Console} = {
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Console.print("Dividing " + toString(a) + " by " + toString(b) + "...")
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if b == 0 then Fail.fail("Division by zero")
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else a / b
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}
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fn main(): Unit with {Console} = {
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// These succeed
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let n1 = run parsePositive("42") with {}
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Console.print("Result: " + toString(n1))
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let n2 = run parsePositive("100") with {}
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Console.print("Result: " + toString(n2))
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let n3 = run safeDivide(100, 4) with {}
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Console.print("Result: " + toString(n3))
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}
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let output = run main() with {}
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