Enum TyDecl 

pub enum TyDecl {
    Model {
        name: Arc<str>,
        params: Vec<Arc<str>>,
        fields: Vec<(Arc<str>, Ty)>,
    },
    Union {
        name: Arc<str>,
        params: Vec<Arc<str>>,
        variants: Vec<Variant>,
    },
    Newtype {
        name: Arc<str>,
        params: Vec<Arc<str>>,
        inner: Ty,
    },
    Alias {
        name: Arc<str>,
        params: Vec<Arc<str>>,
        ty: Ty,
    },
}

A user-declared type: a model (record), a union (ADT), a newtype, or an alias.

Comparable because a .becki interface is compared (§3.6, §4.3): two builds agree on a module’s contract exactly when their type declarations are equal.

params is the declaration’s type-parameter names, in order — union Tree[T] has ["T"]. The names are what a .becki renders and what a doc page shows; the field types refer to the parameters positionally through SCHEME_BASE, so a rename is a rename and nothing more. Arity is params.len(), declared rather than inferred from use: a parameter no field mentions is still a parameter, and Phantom[Int] and Phantom[Str] are still different types.

Variants

Model

Fields

name: Arc<str>

params: Vec<Arc<str>>

fields: Vec<(Arc<str>, Ty)>

Union

Fields

name: Arc<str>

params: Vec<Arc<str>>

variants: Vec<Variant>

Newtype

§3.1’s “zero-cost nominal newtype”: ids of different entities must not be interchangeable.

Fields

name: Arc<str>

params: Vec<Arc<str>>

inner: Ty

Alias

Fields

name: Arc<str>

params: Vec<Arc<str>>

ty: Ty

Implementations

impl TyDecl

pub fn name(&self) -> &Arc<str>

pub fn params(&self) -> &[Arc<str>]

pub fn arity(&self) -> usize

How many type arguments a mention of this name must carry.

pub fn param_brackets(&self) -> String

[T, U], or the empty string when there is nothing to quantify.

pub fn as_written(&self, t: &Ty) -> Ty

One of this declaration’s field types as the declaration wrote it: the positional parameters put back under the names they were given.

Everything downstream of a TyDecl holds its parameters positionally, which is what makes instantiation an index. Rendering is the one place that has to undo it — a .becki is source, and value: ?1000000 is not something the parser can read back.

Trait Implementations

impl Clone for TyDecl

fn clone(&self) -> TyDecl

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TyDecl

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

Formats the value using the given formatter.

impl PartialEq for TyDecl

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for TyDecl

impl StructuralPartialEq for TyDecl