Struct Dist 

pub struct Dist {
    pub subject_ty: Ty,
    pub plain_var: Option<VarId>,
    pub vars: Vec<VarId>,
    pub items: Vec<Item>,
    pub default: Option<DefaultWeight>,
    pub subject: Option<Expr>,
}

One dist expression.

Fields

subject_ty: Ty

The type of the distributed expression.

plain_var: Option<VarId>

The distributed variable, when the expression is exactly one random variable (the case the weighting is exact for).

vars: Vec<VarId>

Every random variable the distributed expression reads, ascending.

items: Vec<Item>

The explicit items, in source order; code i is item i.

default: Option<DefaultWeight>

The default item; its code follows the explicit items’.

subject: Option<Expr>

Some(subject) marks a template: a dist written inside a foreach over a dynamic array or queue (LRM 18.5.7.1, 18.5.3), which must hold once per element. Its expressions are array-level IR over the loop variable and cannot be weighed as they stand: array::expand makes one instance of the dist, with a selector of its own, per iteration (module docs of super::array), expanding subject (the array-level distributed expression), the bounds and the weights for that iteration. A template keeps its selector slot in the program but is never planned itself.

Implementations

impl Dist

pub fn validate(&self) -> Result<(), IrError>

Checks every expression of the dist against the IR’s typing rules and that the weights and bounds read no random variable.

pub fn codes(&self) -> usize

The number of selector codes: one per item, plus the default’s.

pub fn selector_ty(&self) -> Ty

The selector variable’s type: just wide enough for Self::codes.

pub fn conjunct(&self, sel: VarId) -> Expr

The conjunct OR_i (sel == i && member_i) (the default’s member is “no explicit item holds”).

pub fn weights( &self, states: &[Option<BigUint>], ) -> Result<Vec<Weight>, DistError>

The per-value weight of every selector code under the current values of the state variables: item i’s weight (:=) or its weight divided by the number of values of the item (:/), and likewise for the default over the values no explicit item names. A weight of an empty item is 0.

Trait Implementations

impl Clone for Dist

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Dist

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Dist

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for Dist

impl PartialEq for Dist

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for Dist

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 Dist