81 lines
2.3 KiB
Rust

//! Represents a block of code which lives inside the Interpreter
use collect_upvars::collect_upvars;
use super::{Callable, ConValue, Environment, Error, IResult, Interpret};
use cl_ast::{Function as FnDecl, Param, Sym};
use std::{
cell::{Ref, RefCell},
collections::HashMap,
rc::Rc,
};
pub mod collect_upvars;
type Upvars = HashMap<Sym, Option<ConValue>>;
/// Represents a block of code which persists inside the Interpreter
#[derive(Clone, Debug)]
pub struct Function {
/// Stores the contents of the function declaration
decl: Rc<FnDecl>,
/// Stores data from the enclosing scopes
upvars: RefCell<Upvars>,
}
impl Function {
pub fn new(decl: &FnDecl) -> Self {
// let upvars = collect_upvars(decl, env);
Self { decl: decl.clone().into(), upvars: Default::default() }
}
pub fn decl(&self) -> &FnDecl {
&self.decl
}
pub fn upvars(&self) -> Ref<Upvars> {
self.upvars.borrow()
}
pub fn lift_upvars(&self, env: &Environment) {
let upvars = collect_upvars(&self.decl, env);
if let Ok(mut self_upvars) = self.upvars.try_borrow_mut() {
*self_upvars = upvars;
}
}
}
impl Callable for Function {
fn name(&self) -> Sym {
let FnDecl { name, .. } = *self.decl;
name
}
fn call(&self, env: &mut Environment, args: &[ConValue]) -> IResult<ConValue> {
let FnDecl { name, bind, body, sign: _ } = &*self.decl;
// Check arg mapping
if args.len() != bind.len() {
return Err(Error::ArgNumber { want: bind.len(), got: args.len() });
}
let Some(body) = body else {
return Err(Error::NotDefined(*name));
};
let upvars = self.upvars.take();
env.push_frame("upvars", upvars);
// TODO: completely refactor data storage
let mut frame = env.frame("fn args");
for (Param { mutability: _, name }, value) in bind.iter().zip(args) {
frame.insert(*name, Some(value.clone()));
}
let res = body.interpret(&mut frame);
drop(frame);
if let Some((upvars, _)) = env.pop_frame() {
self.upvars.replace(upvars);
}
match res {
Err(Error::Return(value)) => Ok(value),
Err(Error::Break(value)) => Err(Error::BadBreak(value)),
result => result,
}
}
}