Struct VM

pub struct VM {
    ip: usize,
    stack: Vec<Value>,
    scopes: Vec<Scope>,
    frames: Vec<CallFrame>,
    current_frame: Option<usize>,
}

Virtual Machine that executes bytecode

Fields

ip: usize

Instruction pointer

stack: Vec<Value>

Stack for values

scopes: Vec<Scope>

Stack of scopes, with global scope at index 0

frames: Vec<CallFrame>

Call frames for function calls

current_frame: Option<usize>

Index of the current call frame

Implementations

impl VM

pub fn new() -> Self

Creates a new virtual machine

fn register_native_functions(&mut self)

Registers built-in functions

fn define_native( &mut self, name: &str, arity: u8, function: fn(&[Value]) -> Result<Value, String>, )

Defines a native (built-in) function

Arguments

• name - Name of the native function
• arity - Number of parameters
• function - The Rust function implementing this native function

pub fn interpret(&mut self, chunk: &Chunk) -> Result<(), String>

Interprets and executes a bytecode chunk

Arguments

• chunk - The bytecode chunk to execute

Returns

Ok(()) on success, or an error message on failure

fn execute_instruction(&mut self, chunk: &Chunk) -> Result<(), String>

Executes a single instruction

Arguments

• chunk - The bytecode chunk containing the instruction

Returns

Ok(()) on success, or an error message on failure

fn read_byte(&mut self, chunk: &Chunk) -> u8

Reads the next byte from the chunk and advances the instruction pointer

Arguments

• chunk - The bytecode chunk to read from

Returns

The byte read from the chunk

fn pop(&mut self) -> Result<Value, String>

Pops a value off the stack

Returns

The popped value, or an error if the stack is empty

fn peek(&self, distance: usize) -> Result<&Value, String>

Looks at a value on the stack without removing it

Arguments

• distance - How far from the top of the stack to look

Returns

Reference to the value, or an error if the stack isn’t deep enough

fn binary_op<F>(&mut self, op: F) -> Result<(), String>

where F: FnOnce(&Value, &Value) -> Result<Value, String>,

Performs a binary operation on the top two values of the stack

Arguments

• op - Function that implements the binary operation

Returns

Ok(()) if successful, or an error message

fn get_variable(&self, name: &str) -> Option<&Value>

Helper method to find a variable in any scope (from innermost to outermost)

fn set_variable(&mut self, name: String, value: Value)

Helper method to set a variable (creates in current scope or updates existing)

Trait Implementations

impl Default for VM

fn default() -> Self

Returns the “default value” for a type.