Enum ggbasm::ast::Expr

pub enum Expr {
    Ident(String),
    Const(i64),
    Binary(Box<BinaryExpr>),
    Unary(Box<UnaryExpr>),
}

Assembly uses constant expressions to avoid copying magic numbers around. Expr represents these constant expressions.

The run method evaluates the constant expression. The get_2bytes, get_byte and get_bit_index evaluate the constant expression but also convert to a specific low level type needed by instructions.

Variants

Ident(String)

Const(i64)

Binary(Box<BinaryExpr>)

Unary(Box<UnaryExpr>)

Implementations

impl Expr

pub fn binary(left: Expr, operator: BinaryOperator, right: Expr) -> Expr

pub fn unary(expr: Expr, operator: UnaryOperator) -> Expr

pub fn get_2bytes(
    &self,
    constants: &HashMap<String, i64>
) -> Result<[u8; 2], ExprRunError>

pub fn get_byte(
    &self,
    constants: &HashMap<String, i64>
) -> Result<u8, ExprRunError>

pub fn get_bit_index(
    &self,
    constants: &HashMap<String, i64>
) -> Result<u8, ExprRunError>

pub fn run(&self, constants: &HashMap<String, i64>) -> Result<i64, ExprRunError>

Trait Implementations

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.

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: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Expr