d74e36d0bc
Unfortunately, as documented in: https://github.com/IntersectMBO/cardano-ledger/issues/4571 Some Option fields in the script context certificates are going to remain set to None, at least until the next Hard fork. There's a risk that people permanently lock their funds if they expect deposits on registration credentials to ever be `Some`. So, we introduce a special type that emulate an `Option` that can only ever be `None`. We call it `Never` and it is the first type of this kind (i.e. with constructors indexes not starting at 0).
40 lines
589 B
Plaintext
40 lines
589 B
Plaintext
type Foo {
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Foo(Int, Never)
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Bar
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}
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test never_is_none() {
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let none: Option<Void> = None
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trace @"Never": Never
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trace @"None": none
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let data_never: Data = Never
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let data_none: Data = none
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data_never == data_none
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}
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test never_pattern_match() {
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when Foo(14, Never) is {
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Foo(x, Never) -> x == 14
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Bar -> False
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}
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}
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test never_assignment() {
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let Never = Never
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True
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}
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test never_wrong_cast() fail {
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let data: Data = Some(42)
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expect _: Never = data
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}
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test never_ok_cast() {
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let none: Option<Void> = None
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let data: Data = none
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expect _: Never = data
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}
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