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64 lines
2.1 KiB
Rust
64 lines
2.1 KiB
Rust
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// Check that we expand multiple or-patterns from left to right.
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// run-pass
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fn search(target: (bool, bool, bool)) -> u32 {
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let x = ((false, true), (false, true), (false, true));
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let mut guard_count = 0;
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match x {
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((a, _) | (_, a), (b @ _, _) | (_, b @ _), (c @ false, _) | (_, c @ true))
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if {
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guard_count += 1;
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(a, b, c) == target
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} =>
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{
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guard_count
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}
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_ => unreachable!(),
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}
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}
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// Equivalent to the above code, but hopefully easier to understand.
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fn search_old_style(target: (bool, bool, bool)) -> u32 {
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let x = ((false, true), (false, true), (false, true));
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let mut guard_count = 0;
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match x {
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((a, _), (b @ _, _), (c @ false, _))
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| ((a, _), (b @ _, _), (_, c @ true))
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| ((a, _), (_, b @ _), (c @ false, _))
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| ((a, _), (_, b @ _), (_, c @ true))
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| ((_, a), (b @ _, _), (c @ false, _))
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| ((_, a), (b @ _, _), (_, c @ true))
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| ((_, a), (_, b @ _), (c @ false, _))
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| ((_, a), (_, b @ _), (_, c @ true))
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if {
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guard_count += 1;
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(a, b, c) == target
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} =>
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{
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guard_count
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}
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_ => unreachable!(),
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}
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}
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fn main() {
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assert_eq!(search((false, false, false)), 1);
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assert_eq!(search((false, false, true)), 2);
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assert_eq!(search((false, true, false)), 3);
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assert_eq!(search((false, true, true)), 4);
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assert_eq!(search((true, false, false)), 5);
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assert_eq!(search((true, false, true)), 6);
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assert_eq!(search((true, true, false)), 7);
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assert_eq!(search((true, true, true)), 8);
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assert_eq!(search_old_style((false, false, false)), 1);
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assert_eq!(search_old_style((false, false, true)), 2);
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assert_eq!(search_old_style((false, true, false)), 3);
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assert_eq!(search_old_style((false, true, true)), 4);
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assert_eq!(search_old_style((true, false, false)), 5);
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assert_eq!(search_old_style((true, false, true)), 6);
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assert_eq!(search_old_style((true, true, false)), 7);
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assert_eq!(search_old_style((true, true, true)), 8);
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}
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