Struct Environment

pub struct Environment { /* private fields */ }

The environment in which lambda terms get evaluated.

There are two possibilities to create an instance of Environment:

• Environment::new() - creates an empty environment.
• Environment::default() - creates an environment containing predefined bindings to all the builtin standard terms, combinators and data encoding terms.

Implementations

impl Environment

pub fn new() -> Self

Creates a new empty environment.

The empty environment does not contain any bindings at all. If you want to create an environment with predefined bindings to all the builtin standard terms, combinators and data encodings use the Environment::default() function.

pub fn insert_binding(&mut self, binding: Binding)

Adds the given binding to this environment.

pub fn bind(&mut self, name: VarName, term: Term) -> Option<Term>

Adds a new binding of the given term to the given name to this environment.

pub fn unbind(&mut self, name: &VarName) -> Option<Term>

Removes the binding to the given name from this environment and returns the bound term if such a binding previously existed.

pub fn clear_bindings(&mut self)

Removes all bindings from this environment.

pub fn bindings(&self) -> impl Iterator<Item = (&VarName, &Term)>

Returns an iterator over all bindings defined in this environment.

The iterator issues the items in an arbitrary order.

pub fn into_bindings(self) -> impl Iterator<Item = Binding>

Returns an iterator over all bindings defined in this environment.

pub fn lookup_term(&self, name: &VarName) -> Option<&Term>

Looks up the binding for a name and returns a reference to the bound term if a binding exists for the given name.

Trait Implementations

impl Clone for Environment

fn clone(&self) -> Environment

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Environment

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

Formats the value using the given formatter.

impl Default for Environment

fn default() -> Self

Creates an Environment containing predefined bindings to all the standard terms, combinators and data encoding terms that are provided by this crate.

impl Extend<(VarName, Term)> for Environment

fn extend<I: IntoIterator<Item = (VarName, Term)>>(&mut self, iter: I)

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

🔬This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

🔬This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements.

impl Extend<Binding> for Environment

fn extend<I: IntoIterator<Item = Binding>>(&mut self, iter: I)

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

🔬This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

🔬This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements.

impl FromIterator<(VarName, Term)> for Environment

fn from_iter<I>(set: I) -> Self

where I: IntoIterator<Item = (VarName, Term)>,

Creates a value from an iterator.

impl FromIterator<Binding> for Environment

fn from_iter<I>(set: I) -> Self

where I: IntoIterator<Item = Binding>,

Creates a value from an iterator.

impl PartialEq for Environment

fn eq(&self, other: &Environment) -> 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 StructuralPartialEq for Environment