Struct ValueRule 

#[non_exhaustive]
pub struct ValueRule {
    pub min: Option<Decimal>,
    pub max: Option<Decimal>,
    pub step: Option<Decimal>,
}

The grid and range of one kind of value: a price, a quantity or a notional.

Each part is optional. A venue that publishes a zero for one means the rule is off, and ValueRule::new reads zero that way.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

min: Option<Decimal>

The smallest value allowed.

max: Option<Decimal>

The largest value allowed.

step: Option<Decimal>

The value must be a whole multiple of this, counted from zero.

Implementations

impl ValueRule

pub fn new(min: Decimal, max: Decimal, step: Decimal) -> Self

A rule from the venue’s min, max and step, each off when zero or negative.

pub fn is_off(&self) -> bool

Whether every part is off.

pub fn round_down(&self, value: Decimal) -> Option<Decimal>

The largest multiple of step at or below value, counted from zero: the grid the pre-send check uses. A value on the grid comes back unchanged, and so does any value when there is no step.

It does not clamp to min or max: rounding down can take a value below the minimum, down to zero, so check the result before sending it.

A value already on the grid comes back as it is. One that has to move takes the scale of value or step, whichever is finer, so it may carry trailing zeros: 0.19000 rounds down to 0.15000 on a step of 0.05.

Returns None only when a Decimal cannot hold the result: within a step of the ends of its range, or where the result needs more digits than it has.

pub fn round_up(&self, value: Decimal) -> Option<Decimal>

The smallest multiple of step at or above value, counted from zero. As round_down otherwise: rounding up can take a value above the maximum.

Returns None only when a Decimal cannot hold the result, as for round_down.

Trait Implementations

impl Clone for ValueRule

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 ValueRule

impl Debug for ValueRule

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

Formats the value using the given formatter.

impl Default for ValueRule

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ValueRule

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for ValueRule

impl Hash for ValueRule

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 PartialEq for ValueRule

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for ValueRule

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for ValueRule