Struct Function

pub struct Function {
    pub parameters: Vec<String>,
    pub body: Vec<Statement>,
    pub env: EnvRef,
}

This struct is how the interpreter stores functions. It contains the function’s parameters, body and a reference to the environment in which it was defined.

By keeping a reference to the environment where the function was created, the interpreter can access the variables within that environment when the function is called. This also enables the interpreter to create closures.

Closures are functions that retain access to the environment in which they were defined. Even if that environment goes out of scope, the function holds onto that environment, keeping it alive, allowing it to still access the variables within.

Fields

parameters: Vec<String>

body: Vec<Statement>

env: EnvRef

Trait Implementations

impl Debug for Function

Implementing the Debug trait for Function allows printing of the function’s parameters and the number of statements in its body.

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

Formats the value using the given formatter.

impl PartialEq for Function

fn eq(&self, other: &Function) -> 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 Function