Struct HashMapContext

pub struct HashMapContext { /* private fields */ }

A context that stores its mappings in hash maps.

Value and function mappings are stored independently, meaning that there can be a function and a value with the same identifier.

This context is type-safe, meaning that an identifier that is assigned a value of some type once cannot be assigned a value of another type.

Implementations

impl HashMapContext

pub fn new() -> Self

Constructs a HashMapContext with no mappings.

Trait Implementations

impl Clone for HashMapContext

fn clone(&self) -> HashMapContext

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Context for HashMapContext

fn get_value(&self, identifier: &str) -> Option<&Value>

Returns the value that is linked to the given identifier.

fn call_function( &self, identifier: &str, argument: &Value, ) -> EvalexprResult<Value>

Calls the function that is linked to the given identifier with the given argument. If no function with the given identifier is found, this method returns EvalexprError::FunctionIdentifierNotFound.

impl ContextWithMutableFunctions for HashMapContext

fn set_function( &mut self, identifier: String, function: Function, ) -> EvalexprResult<()>

Sets the function with the given identifier to the given function.

impl ContextWithMutableVariables for HashMapContext

fn set_value(&mut self, identifier: String, value: Value) -> EvalexprResult<()>

Sets the variable with the given identifier to the given value.

impl Debug for HashMapContext

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

Formats the value using the given formatter.

impl Default for HashMapContext

fn default() -> HashMapContext

Returns the “default value” for a type.

impl<'a> IterateVariablesContext<'a> for HashMapContext

type VariableIterator = Map<Iter<'a, String, Value>, fn((&String, &Value)) -> (String, Value)>

The iterator type for iterating over variable name-value pairs.

type VariableNameIterator = Cloned<Keys<'a, String, Value>>

The iterator type for iterating over variable names.

fn iter_variables(&'a self) -> Self::VariableIterator

Returns an iterator over pairs of variable names and values.

fn iter_variable_names(&'a self) -> Self::VariableNameIterator

Returns an iterator over variable names.