Struct umbra_lang::Env

pub struct Env<'a> { /* fields omitted */ }

The environment that scripts use to store and access variables.

This contains a reference to a parent Env whose variables are accessible but immutable.

Implementations

impl<'a> Env<'a>

#[must_use]

pub fn core() -> Env<'a>

Clones the Core Env which contains only the variables necessary to bootstrap the language.

#[must_use]

pub fn prelude() -> Env<'a>

Clones the Prelude Env which contains the usual variables for writing programs.

#[must_use]

pub fn empty() -> Env<'a>

Constructs an Env with no parent and no variables.

#[must_use]

pub fn child(parent: &'a Env<'a>) -> Env<'a>

Constructs an Env with the given parent and no variables.

#[must_use]

pub fn iter_flatten<'b>(
    it: &'b Env<'a>
) -> Box<dyn Iterator<Item = (&'b String, &'b RefTVal)> + 'b>

Creates a recursive Iterator over all variables in the given Env and its parents. Parent variables will come first.

#[must_use]

pub fn flatten<'b>(old: &'b Env<'a>) -> Env<'a>

Constructs an Env with no parent and all the variables of the given Env and its parents. Duplicate variables will be overwritten by the one in the child.

#[must_use]

pub fn get(&self, name: &str) -> Option<&RefTVal>

Returns the value of the variable with the given name if it exists. This Env will be checked first, followed by the parents recursively.

#[must_use]

pub fn has(&self, name: &str) -> bool

Returns whether the given name corresponds to a variable.

pub fn set(&mut self, name: &str, rv: &RefTVal)

Inserts the given value with the given name as a variable.

pub fn unset(&mut self, name: &str)

Removes the given name from this Env.

pub fn update(&mut self, vars: HashMap<String, RefTVal>)

Adds all of the variables in the given map to this Env.

pub fn diff(&self, nenv: &'a mut Env<'a>) -> HashMap<String, RefTVal>

Computes the changed vars in the new env nenv that exist in the outside env self.

Trait Implementations

impl<'a> Clone for Env<'a>

fn clone(&self) -> Env<'a>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'a> Debug for Env<'a>

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

Formats the value using the given formatter.

impl<'a> From<HashMap<String, RefTVal, RandomState>> for Env<'a>

fn from(vars: HashMap<String, RefTVal>) -> Env<'a>

Performs the conversion.

impl<'a> PartialEq<Env<'a>> for Env<'a>

fn eq(&self, other: &Env<'a>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Env<'a>) -> bool

This method tests for !=.

impl<'a> Eq for Env<'a>

impl<'a> StructuralEq for Env<'a>

impl<'a> StructuralPartialEq for Env<'a>