Struct Context

pub struct Context { /* private fields */ }

The context for evaluating expressions and statements in.

Maps names to functions and values.

Implementations

impl Context

pub fn new() -> Context

Create a new empty context.

pub fn add_scope(&mut self, values: HashMap<String, Number>)

Add a new scope of values to the context.

pub fn lookup_value(&self, name: &str) -> CalcResult

Lookup a value in the context. Returns the CalcError::NameNotFound if the name is not mapped in the context (in any scope). If the name is in multiple scopes it returns the value from the last scope.

pub fn lookup_fn(&self, name: &str) -> Result<CalcFuncRef<'_>, CalcError>

Lookup a function in the context. Returns the CalcError::NameNotFound if the name is not mapped in the context (in any scope). If the name is in multiple scopes it returns the value from the last scope.

pub fn bind_value(&mut self, name: String, value: Number) -> CalcResult

Bind value to name in the top scope. If name is the name of a builtin value nothing will be bound and the function will return CalcError::NameAlreadyBound.

pub fn bind_fn(&mut self, name: String, func: UserFunc) -> Result<(), CalcError>

Bind func to name in the top scope. If name is the name of a builtin function nothing will be bound and the function will return CalcError::NameAlreadyBound.

Trait Implementations

impl Clone for Context

fn clone(&self) -> Context

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'de> Deserialize<'de> for Context

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Context

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.