Public API and docs

src/stl/cpsio/panic.rs

@@ -0,0 +1,35 @@
+use std::fmt::Display;
+
+use super::super::litconv::with_str;
+use crate::foreign::ExternError;
+use crate::representations::interpreted::ExprInst;
+use crate::{atomic_impl, atomic_redirect, externfn_impl};
+
+/// Takes a message, returns an [ExternError] unconditionally.
+///
+/// Next state: [Panic0]
+#[derive(Clone)]
+pub struct Panic1;
+externfn_impl!(Panic1, |_: &Self, x: ExprInst| Ok(Panic0 { x }));
+
+/// Prev state: [Panic1]
+#[derive(Debug, Clone)]
+pub struct Panic0 {
+  x: ExprInst,
+}
+atomic_redirect!(Panic0, x);
+atomic_impl!(Panic0, |Self { x }: &Self, _| {
+  with_str(x, |s| Err(OrchidPanic(s.clone()).into_extern()))
+});
+
+/// An unrecoverable error in Orchid land. Of course, because Orchid is lazy, it
+/// only applies to the expressions that use the one that generated it.
+pub struct OrchidPanic(String);
+
+impl Display for OrchidPanic {
+  fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+    write!(f, "Orchid code panicked: {}", self.0)
+  }
+}
+
+impl ExternError for OrchidPanic {}