Enum rsc::parser::Expr

pub enum Expr {
    BinOp(Operator, Box<Expr>, Box<Expr>),
    Pow(Box<Expr>, Box<Expr>),
    Neg(Box<Expr>),
    Function(Function, Box<Expr>),
    Assignment(String, Box<Expr>),
    Constant(f64),
    Identifier(String),
}

Variants

BinOp(Operator, Box<Expr>, Box<Expr>)Pow(Box<Expr>, Box<Expr>)Neg(Box<Expr>)Function(Function, Box<Expr>)Assignment(String, Box<Expr>)Constant(f64)Identifier(String)

Methods

impl Expr

pub fn replace(&mut self, old: &Expr, new: &Expr, ignore_fields: bool) -> bool

Replaces all instances of old with new. This method returns true if a value has been replaced, and false otherwise.

Example

One could use this function to replace all references to an identifier "x" with the constant 20.

let input = "x^2 * 4";
let replacement = parser::Expr::Constant(20.);
let mut ast = parser::parse(&lexer::tokenize(&input).unwrap()).unwrap();
ast.replace(&parser::Expr::Identifier(String::from("x")), &replacement, false);
assert_eq!(computer::compute(&ast), 1600.);

Trait Implementations

impl PartialEq<Expr> for Expr

fn eq(&self, other: &Expr) -> bool

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

fn ne(&self, other: &Expr) -> bool

This method tests for !=.

impl Clone for Expr

fn clone(&self) -> Expr

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Expr

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

Formats the value using the given formatter.