pub enum Kind {
    Value(Value),
    Error(ErrorSet),
    Unknown(UnknownSet),
}
Expand description

An expression can resolve to a value, error or unknown.

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Value(Value)

A concrete value.

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Error(ErrorSet)

The set of errors in the critical path of evalution.

Only errors in the critical path are included. For example, (<error1> || true) && <error2> will only result in <error2>, while <error1> || <error2> will result in both <error1> and <error2>.

Errors cause by the presence of other errors are not included in the set. For example <error1>.foo, foo(<error1>), and <error1> + 1 will only result in <error1>.

Multiple errors might be included when evaluation could result in different errors. For example <error1> + <error2> and foo(<error1>, <error2>) may result in <error1>, <error2> or both. The exact subset of errors included for this case is unspecified and depends on the implementation details of the evaluator.

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Unknown(UnknownSet)

The set of unknowns in the critical path of evaluation.

Unknown behaves identically to Error with regards to propagation. Specifically, only unknowns in the critical path are included, unknowns caused by the presence of other unknowns are not included, and multiple unknowns might be included included when evaluation could result in different unknowns. For example:

 (<unknown\[1\]> || true) && <unknown\[2\]> -> <unknown\[2\]>
 <unknown\[1\]> || <unknown\[2\]> -> <unknown\[1,2\]>
 <unknown\[1\]>.foo -> <unknown\[1\]>
 foo(<unknown\[1\]>) -> <unknown\[1\]>
 <unknown\[1\]> + <unknown\[2\]> -> <unknown\[1\]> or <unknown[2[>

Unknown takes precidence over Error in cases where a Value can short circuit the result:

 <error> || <unknown> -> <unknown>
 <error> && <unknown> -> <unknown>

Errors take precidence in all other cases:

 <unknown> + <error> -> <error>
 foo(<unknown>, <error>) -> <error>

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impl Kind

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pub fn encode<B>(&self, buf: &mut B)
where B: BufMut,

Encodes the message to a buffer.

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pub fn merge<B>( field: &mut Option<Kind>, tag: u32, wire_type: WireType, buf: &mut B, ctx: DecodeContext ) -> Result<(), DecodeError>
where B: Buf,

Decodes an instance of the message from a buffer, and merges it into self.

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pub fn encoded_len(&self) -> usize

Returns the encoded length of the message without a length delimiter.

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impl Clone for Kind

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fn clone(&self) -> Kind

Returns a copy of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl Debug for Kind

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fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter. Read more
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impl PartialEq for Kind

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fn eq(&self, other: &Kind) -> bool

This method tests for self and other values to be equal, and is used by ==.
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fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
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impl StructuralPartialEq for Kind

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impl !Freeze for Kind

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impl RefUnwindSafe for Kind

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impl Send for Kind

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impl Sync for Kind

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impl Unpin for Kind

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impl UnwindSafe for Kind

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T> FromRef<T> for T
where T: Clone,

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fn from_ref(input: &T) -> T

Converts to this type from a reference to the input type.
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impl<T> Instrument for T

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fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided [Span], returning an Instrumented wrapper. Read more
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fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> IntoRequest<T> for T

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fn into_request(self) -> Request<T>

Wrap the input message T in a tonic::Request
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impl<T> ToOwned for T
where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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impl<V, T> VZip<V> for T
where V: MultiLane<T>,

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fn vzip(self) -> V

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impl<T> WithSubscriber for T

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fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a [WithDispatch] wrapper. Read more
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fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a [WithDispatch] wrapper. Read more