Struct edn::entities::TxFunction

pub struct TxFunction {
    pub op: PlainSymbol,
}

A "transaction function" that exposes some value determined by the current transaction. The prototypical example is the current transaction ID, (transaction-tx).

A natural next step might be to expose the current transaction instant (transaction-instant), but that's more difficult: the transaction itself can set the transaction instant (with some restrictions), so the transaction function must be late-binding. Right now, that's difficult to arrange in the transactor.

In the future, we might accept arguments; for example, perhaps we might expose (ancestor (transaction-tx) n) to find the n-th ancestor of the current transaction. If we do accept arguments, then the special case of (lookup-ref a v) should be handled as part of the generalization.

Fields

op: PlainSymbol

Trait Implementations

impl Clone for TxFunction

fn clone(&self) -> TxFunction

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for TxFunction

fn fmt(&self, __arg_0: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Eq for TxFunction

impl Hash for TxFunction

fn hash<__H: Hasher>(&self, __arg_0: &mut __H)

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given [Hasher].

impl Ord for TxFunction

fn cmp(&self, __arg_0: &TxFunction) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

impl PartialOrd for TxFunction

fn partial_cmp(&self, __arg_0: &TxFunction) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, __arg_0: &TxFunction) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, __arg_0: &TxFunction) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, __arg_0: &TxFunction) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, __arg_0: &TxFunction) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl PartialEq for TxFunction

fn eq(&self, __arg_0: &TxFunction) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, __arg_0: &TxFunction) -> bool

This method tests for !=.

impl<V: TransactableValueMarker> From<TxFunction> for ValuePlace<V>

fn from(v: TxFunction) -> Self

Performs the conversion.

impl<V: TransactableValueMarker> From<TxFunction> for EntityPlace<V>

fn from(v: TxFunction) -> Self

Performs the conversion.