Enum Type 

pub enum Type {
    Primitive(Primitive),
    Nominal {
        name: String,
        symbol: Option<Symbol>,
    },
    Union(Vec<Type>),
}

What the oracle established about an expression.

There is no Unknown variant on purpose: not knowing is None at the API boundary, so there is exactly one spelling of it. A variant would give callers two, and the interesting bug is a rule that treats one of them as an answer.

Variants

Primitive(Primitive)

A primitive.

Nominal

A type named by an identifier — Decimal, Account. Nominal, by name: the oracle compares names and does not compute structural assignability.

Fields

name: String

The name as written.

symbol: Option<Symbol>

Where that name came from, when the resolver could say.

Union(Vec<Type>)

Two or more distinct members, flattened one level, in canonical order.

Implementations

impl Type

pub fn union(members: Vec<Self>) -> Option<Self>

Build a union from its members, or the single type if that is what it comes to.

Members are flattened one level, deduplicated and sorted. Sorting is not the determinism requirement — source order is deterministic too — it is that string | number and number | string are the same type and must produce one answer. Ord on Type puts primitives before nominals and orders each group by name, which is a total order over everything this crate can build.

Returns None for an empty union, which is not a type and must not be reported as one.

Trait Implementations

impl Clone for Type

fn clone(&self) -> Type

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Type

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

Formats the value using the given formatter.

impl Eq for Type

impl Ord for Type

fn cmp(&self, other: &Type) -> 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 Type

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

Equality operator ==.

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

Inequality operator !=.

impl PartialOrd for Type

fn partial_cmp(&self, other: &Type) -> 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 StructuralPartialEq for Type