Files
orchid/orchid-extension/src/conv.rs

69 lines
1.7 KiB
Rust

use std::future::Future;
use orchid_base::error::{OrcErr, OrcRes, mk_err};
use orchid_base::interner::Interner;
use orchid_base::location::Pos;
use crate::atom::{AtomicFeatures, ToAtom, TypAtom};
use crate::expr::Expr;
use crate::gen_expr::{GExpr, atom, bot};
use crate::system::downcast_atom;
pub trait TryFromExpr: Sized {
fn try_from_expr(expr: Expr) -> impl Future<Output = OrcRes<Self>>;
}
impl TryFromExpr for Expr {
async fn try_from_expr(expr: Expr) -> OrcRes<Self> { Ok(expr) }
}
impl<T: TryFromExpr, U: TryFromExpr> TryFromExpr for (T, U) {
async fn try_from_expr(expr: Expr) -> OrcRes<Self> {
Ok((T::try_from_expr(expr.clone()).await?, U::try_from_expr(expr).await?))
}
}
async fn err_not_atom(pos: Pos, i: &Interner) -> OrcErr {
mk_err(i.i("Expected an atom").await, "This expression is not an atom", [pos.into()])
}
async fn err_type(pos: Pos, i: &Interner) -> OrcErr {
mk_err(i.i("Type error").await, "The atom is a different type than expected", [pos.into()])
}
impl<A: AtomicFeatures> TryFromExpr for TypAtom<'_, A> {
async fn try_from_expr(expr: Expr) -> OrcRes<Self> {
match expr.atom().await {
Err(ex) => Err(err_not_atom(ex.data().await.pos.clone(), ex.ctx().i()).await.into()),
Ok(f) => match downcast_atom::<A>(f).await {
Ok(a) => Ok(a),
Err(f) => Err(err_type(f.pos(), f.ctx().i()).await.into()),
},
}
}
}
pub trait ToExpr {
fn to_expr(self) -> GExpr;
}
impl ToExpr for GExpr {
fn to_expr(self) -> GExpr { self }
}
impl ToExpr for Expr {
fn to_expr(self) -> GExpr { self.gen() }
}
impl<T: ToExpr> ToExpr for OrcRes<T> {
fn to_expr(self) -> GExpr {
match self {
Err(e) => bot(e),
Ok(t) => t.to_expr(),
}
}
}
impl<A: ToAtom> ToExpr for A {
fn to_expr(self) -> GExpr { atom(self) }
}