Enum ReduceOnly 

#[non_exhaustive]
pub enum ReduceOnly {
    No,
    Position,
    PositionAndFreeBase,
}

Whether an open order may only reduce the position it closes, and whether it may also trade the account’s free base beyond it. Set on RequestOpen::reduce_only.

A venue that takes an open or close intent, or a reduce-only flag, is sent the same for both reduce-only values: see Self::is_reduce_only. They differ in how the rustrade engine books a fill larger than the position. It cuts the fill so the position lands flat either way (see Trade::holding_move), and then:

• for Position, reads the excess as a mistake: logged at WARN, and counted as a reduce-only fill cut;
• for PositionAndFreeBase on a spot instrument, reads it as a trade of free base the order was sized to make, when the fill moved against the position or the position was flat: logged at INFO, and counted apart. A fill that only grows the position is read as a mistake, as for Position.

Serialised form

"no", "position" or "position_and_free_base". In a human-readable format such as JSON, a false or true, the form before this type replaced a flag, loads as No or Position. A binary format, which cannot say which of the two it holds, reads the variant alone, as serde derives it.

#[non_exhaustive], so a value can be added without breaking a caller. An adapter reads Self::is_reduce_only rather than matching the values.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

No

The order may open or grow a position.

Position

The order only reduces the position it closes. Excess over the position is a mistake.

PositionAndFreeBase

The order reduces the position it closes, and may trade base beyond it out of, or into, the account’s free balance. Meant for spot instruments, spot margin included.

The excess must continue the way the order reduces: past the position, or from flat.

• A sell above a long, or from flat, sells free base: the base-fee remainder that a spot position leaves out (see the rustrade engine’s EngineState::free_base), or base the account holds for another reason.
• A buy above a short, or from flat, buys base the account owes outside the position, as one sized to cover a short’s loan and its interest in base does.

Size it from the base the account holds, or owes, outside the position, so the excess never sells more than the account has. The engine does not check the size: it takes the excess as the order was sized. A fill that only grows the position, a buy while long or a sell while short, reduces nothing, and is booked as for Position.

A venue that enforces reduce-only itself, rather than ignoring it, may refuse or trim the excess. On a derivative, which has no free base, the engine books excess as for Position.

Implementations

impl ReduceOnly

pub const fn is_reduce_only(self) -> bool

Whether the order may only reduce a position: anything but No. The intent or flag an adapter sends the venue.

Trait Implementations

impl Clone for ReduceOnly

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ReduceOnly

impl Debug for ReduceOnly

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

Formats the value using the given formatter.

impl Default for ReduceOnly

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ReduceOnly

fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error>

Deserialize this value from the given Serde deserializer.

impl Eq for ReduceOnly

impl Hash for ReduceOnly

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

Feeds this value into the given Hasher.

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

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for ReduceOnly

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

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

where Self: Sized,

Compares and returns the maximum of two values.

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

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

🔬This is a nightly-only experimental API. (clamp_to)

Restrict a value to a certain range.

impl PartialEq for ReduceOnly

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

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl PartialOrd for ReduceOnly

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

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

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

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

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

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

impl Serialize for ReduceOnly

fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error>

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for ReduceOnly