[−][src]Enum async_graphql::types::MaybeUndefined
pub enum MaybeUndefined<T> { Undefined, Null, Value(T), }
Similar to Option
, but it has three states, undefined
, null
and x
.
Reference: https://spec.graphql.org/June2018/#sec-Null-Value
Examples
use async_graphql::*; struct Query; #[Object] impl Query { async fn value1(&self, input: MaybeUndefined<i32>) -> i32 { if input.is_null() { 1 } else if input.is_undefined() { 2 } else { input.take().unwrap() } } } #[async_std::main] async fn main() { let schema = Schema::new(Query, EmptyMutation, EmptySubscription); let query = r#" { v1:value1(input: 99) v2:value1(input: null) v3:value1 }"#; assert_eq!( schema.execute(query).await.into_result().unwrap().data, value!({ "v1": 99, "v2": 1, "v3": 2, }) ); }
Variants
Implementations
impl<T> MaybeUndefined<T>
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pub fn is_undefined(&self) -> bool
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Returns true if the MaybeUndefined
pub fn is_null(&self) -> bool
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Returns true if the MaybeUndefined
pub fn is_value(&self) -> bool
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Returns true if the MaybeUndefined
pub fn value(&self) -> Option<&T>
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Borrow the value, returns None
if the value is undefined
or null
, otherwise returns Some(T)
.
pub fn take(self) -> Option<T>
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Convert MaybeUndefined
Trait Implementations
impl<T: Clone> Clone for MaybeUndefined<T>
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impl<T: Copy> Copy for MaybeUndefined<T>
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impl<T: Debug> Debug for MaybeUndefined<T>
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impl<T> Default for MaybeUndefined<T>
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impl<'de, T> Deserialize<'de> for MaybeUndefined<T> where
T: Deserialize<'de>,
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T: Deserialize<'de>,
impl<T: Eq> Eq for MaybeUndefined<T>
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impl<T: Hash> Hash for MaybeUndefined<T>
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impl<T: InputType> InputType for MaybeUndefined<T>
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impl<T: Ord> Ord for MaybeUndefined<T>
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impl<T: PartialEq> PartialEq<MaybeUndefined<T>> for MaybeUndefined<T>
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impl<T: PartialOrd> PartialOrd<MaybeUndefined<T>> for MaybeUndefined<T>
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impl<T: Serialize> Serialize for MaybeUndefined<T>
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impl<T> StructuralEq for MaybeUndefined<T>
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impl<T> StructuralPartialEq for MaybeUndefined<T>
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impl<T: Type> Type for MaybeUndefined<T>
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Auto Trait Implementations
impl<T> RefUnwindSafe for MaybeUndefined<T> where
T: RefUnwindSafe,
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T: RefUnwindSafe,
impl<T> Send for MaybeUndefined<T> where
T: Send,
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T: Send,
impl<T> Sync for MaybeUndefined<T> where
T: Sync,
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T: Sync,
impl<T> Unpin for MaybeUndefined<T> where
T: Unpin,
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T: Unpin,
impl<T> UnwindSafe for MaybeUndefined<T> where
T: UnwindSafe,
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T: UnwindSafe,
Blanket Implementations
impl<T> Any for T where
T: 'static + ?Sized,
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T: 'static + ?Sized,
impl<T> Borrow<T> for T where
T: ?Sized,
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T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
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T: ?Sized,
impl<T> CallHasher for T where
T: Hash,
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T: Hash,
impl<T> DeserializeOwned for T where
T: for<'de> Deserialize<'de>,
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T: for<'de> Deserialize<'de>,
impl<Q, K> Equivalent<K> for Q where
K: Borrow<Q> + ?Sized,
Q: Eq + ?Sized,
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K: Borrow<Q> + ?Sized,
Q: Eq + ?Sized,
impl<T> From<T> for T
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impl<T> Instrument for T
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impl<T, U> Into<U> for T where
U: From<T>,
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U: From<T>,
impl<T> RuleType for T where
T: Eq + Ord + Copy + Debug + Hash,
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T: Eq + Ord + Copy + Debug + Hash,
impl<T> Same<T> for T
type Output = T
Should always be Self
impl<T> ToOwned for T where
T: Clone,
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T: Clone,
impl<T, U> TryFrom<U> for T where
U: Into<T>,
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U: Into<T>,
impl<T, U> TryInto<U> for T where
U: TryFrom<T>,
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U: TryFrom<T>,
impl<V, T> VZip<V> for T where
V: MultiLane<T>,
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V: MultiLane<T>,