Enum LambdaType 

pub enum LambdaType {
    A,
    E,
    T,
    Composition(Box<LambdaType>, Box<LambdaType>),
}

The basic type system of the lambda calculus and LOT.

Variants

A

A type for crate::Actors

E

A type for crate::Events

T

A type for truth values.

Composition(Box<LambdaType>, Box<LambdaType>)

A type for functions

Implementations

impl LambdaType

pub fn lift_type(self) -> LambdaType

Takes a type x and returns <<x,t>, t>

pub fn retrievable_types(&self) -> RetrievableTypeIterator<'_>

Get all types which can be created from this type (what you would need to pass before to produce that type).

Examples

• <a,t> can create t (arg: a)
• <a,<a,t>> can create t: (arg: a) or <a,t> (arg: a)
• <a, <<a,t>, <t,t>>> can create <<a,t>, <t,t>> (arg: a), <t,t> (arg: <a,t>) or t

let x = LambdaType::from_string("<a, <<a,t>, <t,t>>>")?
    .retrievable_types()
    .map(|(_, x)| x.to_string())
    .collect::<Vec<_>>();
assert_eq!(x, vec!["<<a,t>,<t,t>>", "<t,t>", "t"]);

pub fn is_lifted_type_of(&self, t: &LambdaType) -> bool

Checks if the type is the lifted version of another.

pub fn add_right_argument(&mut self, other: LambdaType)

Takes a type t and argument x and returns <t, x>

pub fn add_left_argument(&mut self, other: LambdaType)

Takes a type t and argument x and returns <x, t>

pub fn from_string(s: &str) -> Result<Self, TypeParsingError>

Parse a type

let x = LambdaType::from_string("<e,<e,t>>")?;

Errors

Returns a TypeParsingError if the string is malformed and doesn’t represent a type.

pub fn a() -> &'static Self

Get the atomic type a

pub fn e() -> &'static Self

get the atomic type e

pub fn t() -> &'static Self

Get the atomic type t

pub fn compose(a: Self, b: Self) -> Self

Compose two functions

pub fn at() -> &'static Self

Get the a to t function type.

pub fn et() -> &'static Self

Get the e to t function type.

pub fn eet() -> &'static Self

Get the <e,<e,t>> function type

pub fn ett() -> &'static Self

Get the <<e,t>, t> function type

pub fn size(&self) -> usize

The number of elements in this type

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

Check if self can have other applied to it.

pub fn split(&self) -> Result<(&LambdaType, &LambdaType), TypeError>

Split a function type into input and output.

Errors

Returns a TypeError if the type is not a function.

pub fn apply(&self, other: &Self) -> Result<&Self, TypeError>

Applies a function type to self.

Errors

Returns a TypeError if the type is not the right type for the function.

pub fn is_function(&self) -> bool

Checks that the type is a function.

pub fn lhs(&self) -> Result<&Self, TypeError>

Get the left-hand side of a function.

Errors

Returns a TypeError if the type is not a function.

pub fn is_one_place_function(&self) -> bool

Checks if the type takes a primitive type and returns a primitive type

pub fn rhs(&self) -> Result<&Self, TypeError>

Get the right-hand side of a function.

Errors

Returns a TypeError if the type is not a function.

impl LambdaType

pub fn random(r: &mut impl Rng) -> Self

Get a random lambda type.

pub fn random_no_e(r: &mut impl Rng) -> Self

Returns a random type, except for LambdaType::E

Trait Implementations

impl Clone for LambdaType

fn clone(&self) -> LambdaType

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for LambdaType

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

Formats the value using the given formatter.

impl Default for LambdaType

fn default() -> LambdaType

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for LambdaType

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

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for LambdaType

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

Formats the value using the given formatter.

impl From<ActorOrEvent> for LambdaType

fn from(value: ActorOrEvent) -> Self

Converts to this type from the input type.

impl Hash for LambdaType

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 LambdaType

fn cmp(&self, other: &LambdaType) -> 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.

impl PartialEq for LambdaType

fn eq(&self, other: &LambdaType) -> 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 PartialOrd for LambdaType

fn partial_cmp(&self, other: &LambdaType) -> 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 LambdaType

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

where S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for LambdaType

impl StructuralPartialEq for LambdaType