Panicking

compiler/codegen_llvm/src/lib.rs

@@ -294,6 +294,7 @@ impl<'a, 'ctx> Generator<'a, 'ctx> {
             }
             Substituted(_) => todo!(),
             IO(_) => todo!(),
+            Panic(_) => todo!(),
             Error => todo!(),
         }
     }
@@ -341,6 +342,7 @@ impl<'a, 'ctx> Generator<'a, 'ctx> {
             IntrinsicApplication(_) => todo!(),
             Projection(_) => todo!(),
             IO(_) => todo!(),
+            Panic(_) => todo!(),
             // @Question how should we handle that?
             Error => todo!(),
         };
@@ -407,6 +409,7 @@ impl<'a, 'ctx> Generator<'a, 'ctx> {
             IntrinsicApplication(_) => todo!(),
             Projection(_) => todo!(),
             IO(_) => todo!(),
+            Panic(_) => todo!(),
             Error => todo!(),
         }
     }
@@ -451,6 +454,7 @@ impl ExpressionExt for hir::Expression {
             Substituted(_) => todo!(),
             Projection(_) => todo!(),
             IO(_) => todo!(),
+            Panic(_) => todo!(),
             Error => todo!(),
         }
     }

compiler/hir/src/interfaceable.rs

@@ -4,6 +4,7 @@ use utilities::{Int, Nat};
 
 /// An “interfaceable” type (i.e. an intrinsic or known type).
 pub enum Type {
+    Void,
     Unit,
     Bool,
     Nat,
@@ -31,10 +32,16 @@ pub enum Value {
         type_: Type,
         value: Option<Box<Value>>,
     },
+    // @Task rename to Effect
     IO {
         index: usize,
         arguments: Vec<Value>,
     },
+    // @Task make this an effect
+    Panic {
+        message: String,
+    },
+    Opaque(()),
 }
 
 /// Rust types that can be mapped to interfaceable lushui types.
@@ -77,6 +84,16 @@ simple_value_correspondence! {
     i64 => Int64,
 }
 
+impl IntoValue for ! {
+    fn into_type() -> Type {
+        Type::Void
+    }
+
+    fn into_value(self) -> Value {
+        self
+    }
+}
+
 impl IntoValue for () {
     fn into_type() -> Type {
         Type::Unit

compiler/hir/src/intrinsic.rs

@@ -105,6 +105,7 @@ pub enum Function {
     Concat,
     AddNat32,
     Print,
+    Panic,
 }
 
 impl fmt::Display for Function {
@@ -162,11 +163,16 @@ pub fn functions() -> HashMap<Function, FunctionValue> {
             arguments: vec![Value::Text(message)],
         }),
     );
+    intrinsics.insert(
+        Panic,
+        pure!(|_type: Opaque, message: Text| Value::Panic { message }),
+    );
 
     intrinsics
 }
 
 macro pure(|$( $var:ident: $variant:ident ),*| $body:expr ) {
+    #[allow(unreachable_code)]
     FunctionValue {
         arity: count!($( $var )*),
         function: |arguments| {

compiler/hir/src/known.rs

@@ -1,6 +1,8 @@
 /// A known binding.
 #[derive(PartialEq, Eq, Hash, Clone, Copy)]
 pub enum Binding {
+    /// The type `Void`.
+    Void,
     /// The type `Unit`.
     Unit,
     /// The value `Unit.unit`.
@@ -23,6 +25,7 @@ impl Binding {
     #[must_use]
     pub fn parse(namespace: Option<&str>, binder: &str) -> Option<Self> {
         Some(match (namespace, binder) {
+            (None, "Void") => Self::Void,
             (None, "Unit") => Self::Unit,
             (Some("Unit"), "unit") => Self::UnitUnit,
             (None, "Bool") => Self::Bool,
@@ -37,6 +40,7 @@ impl Binding {
 
     pub const fn path(self) -> &'static str {
         match self {
+            Self::Void => "Void",
             Self::Unit => "Unit",
             Self::UnitUnit => "Unit.unit",
             Self::Bool => "Bool",

compiler/hir/src/lib.rs

@@ -1,5 +1,5 @@
 //! The high-level intermediate representation.
-#![feature(decl_macro, default_free_fn)]
+#![feature(decl_macro, default_free_fn, never_type, never_type_fallback)]
 
 use ast::Explicitness;
 pub use entity::{Entity, EntityKind};
@@ -104,7 +104,7 @@ impl From<Use> for BareDeclaration {
 
 pub type Expression = Item<BareExpression>;
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub enum BareExpression {
     PiType(Box<PiType>),
     Application(Box<Application<Expression>>),
@@ -118,7 +118,10 @@ pub enum BareExpression {
     Substituted(Box<Substituted>),
     IntrinsicApplication(Box<IntrinsicApplication>),
     Projection(Box<Projection>),
+    // @Task rename to Effect
     IO(Box<IO>),
+    // @Task make this an effect
+    Panic(Box<Panic>),
     Error,
 }
 
@@ -128,7 +131,7 @@ impl PossiblyErroneous for BareExpression {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct PiType {
     pub explicitness: Explicitness,
     pub laziness: Option<Span>,
@@ -173,7 +176,7 @@ impl From<Binding> for BareExpression {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct Lambda {
     pub parameter: Identifier,
     pub parameter_type_annotation: Option<Expression>,
@@ -189,7 +192,7 @@ impl From<Lambda> for BareExpression {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct CaseAnalysis {
     pub scrutinee: Expression,
     pub cases: Vec<Case>,
@@ -201,7 +204,7 @@ impl From<CaseAnalysis> for BareExpression {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct Substituted {
     pub substitution: Substitution,
     pub expression: Expression,
@@ -213,13 +216,13 @@ impl From<Substituted> for BareExpression {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub enum Substitution {
     Shift(usize),
     Use(Box<Substitution>, Expression),
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct IntrinsicApplication {
     pub callee: Identifier,
     pub arguments: Vec<Expression>,
@@ -231,12 +234,12 @@ impl From<IntrinsicApplication> for BareExpression {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct Projection {
     // @Task
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct IO {
     pub index: usize, // @Task IOIndex
     pub arguments: Vec<Expression>,
@@ -249,15 +252,27 @@ impl From<IO> for BareExpression {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
+// @Temporary
+pub struct Panic {
+    pub message: String,
+}
+
+impl From<Panic> for BareExpression {
+    fn from(panic: Panic) -> Self {
+        Self::Panic(Box::new(panic))
+    }
+}
+
+#[derive(Clone, Debug)]
 pub struct Case {
     pub pattern: Pattern,
     pub body: Expression,
 }
 
 pub type Pattern = Item<BarePattern>;
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 #[allow(clippy::box_collection)]
 pub enum BarePattern {
     Number(Box<Number>),
@@ -298,7 +313,7 @@ impl From<Binding> for BarePattern {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct Binder(pub Identifier);
 
 impl From<Binder> for BarePattern {
@@ -313,17 +328,17 @@ impl From<Application<Pattern>> for BarePattern {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct Binding(pub Identifier);
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct Application<T> {
     pub callee: T,
     pub explicitness: Explicitness,
     pub argument: T,
 }
 
-#[derive(Clone, PartialEq, Eq)]
+#[derive(Clone, PartialEq, Eq, Debug)]
 pub enum Number {
     Nat(Nat),
     Nat32(u32),
@@ -376,7 +391,7 @@ impl fmt::Display for Number {
     }
 }
 
-#[derive(Clone, PartialEq, Eq)]
+#[derive(Clone, PartialEq, Eq, Debug)]
 pub enum Text {
     Text(String),
 }

compiler/hir_format/src/lib.rs

@@ -243,6 +243,8 @@ fn write_lower_expression(
             }
             write!(f, ")")
         }
+        // @Temporary, @Task just write it out as an application of `panic`
+        Panic(panic) => write!(f, "?(panic {:?})", panic.message),
         Substituted(substituted) => {
             write!(f, "?(substituted ",)?;
             substituted.substitution.write(context, f)?;

compiler/item/src/lib.rs

@@ -6,7 +6,7 @@ use span::{Span, Spanning};
 use std::default::default;
 
 /// Something with a source location and attributes.
-#[derive(Clone, PartialEq, Eq)]
+#[derive(Clone, PartialEq, Eq, Debug)]
 pub struct Item<Bare, Attributes> {
     pub bare: Bare,
     pub span: Span,

compiler/lowered_ast/src/attributes.rs

@@ -238,7 +238,7 @@ impl Targets {
     }
 }
 
-#[derive(Clone, Default)]
+#[derive(Clone, Default, Debug)]
 pub struct Attributes(pub Vec<Attribute>);
 
 impl Attributes {
@@ -290,7 +290,7 @@ impl PossiblyErroneous for Attributes {
 
 pub type Attribute = Spanned<BareAttribute>;
 
-#[derive(Clone, PartialEq, Eq, Hash, Discriminant)]
+#[derive(Clone, PartialEq, Eq, Hash, Discriminant, Debug)]
 #[discriminant(name: AttributeName)]
 pub enum BareAttribute {
     /// Hide the constructors of a (public) data type.
@@ -754,7 +754,7 @@ data_queries! {
     Public: Public = BareAttribute::Public(reach) => reach,
 }
 
-#[derive(Clone, PartialEq, Eq, Hash)]
+#[derive(Clone, PartialEq, Eq, Hash, Debug)]
 
 pub struct Deprecated {
     pub reason: Option<Atom>,
@@ -763,18 +763,18 @@ pub struct Deprecated {
     pub replacement: Option<Atom>,
 }
 
-#[derive(Clone, PartialEq, Eq, Hash)]
+#[derive(Clone, PartialEq, Eq, Hash, Debug)]
 pub struct Public {
     pub reach: Option<ast::Path>,
 }
 
-#[derive(Clone, PartialEq, Eq, Hash)]
+#[derive(Clone, PartialEq, Eq, Hash, Debug)]
 pub struct Unstable {
     pub feature: Feature,
     pub reason: String,
 }
 
-#[derive(Clone, PartialEq, Eq, Hash)]
+#[derive(Clone, PartialEq, Eq, Hash, Debug)]
 pub enum Lint {}
 
 impl fmt::Display for Lint {
@@ -786,7 +786,7 @@ impl fmt::Display for Lint {
 #[derive(Clone, PartialEq, Eq, Hash, Debug)]
 pub enum Version {}
 
-#[derive(Clone, PartialEq, Eq, Hash)]
+#[derive(Clone, PartialEq, Eq, Hash, Debug)]
 pub enum Condition {}
 
 impl fmt::Display for Condition {
@@ -795,7 +795,7 @@ impl fmt::Display for Condition {
     }
 }
 
-#[derive(Clone, PartialEq, Eq, Hash)]
+#[derive(Clone, PartialEq, Eq, Hash, Debug)]
 pub enum Feature {}
 
 impl fmt::Display for Feature {

compiler/server/src/lib.rs

@@ -474,6 +474,7 @@ impl FindBinding for hir::Expression {
             IntrinsicApplication(_) => None, // @Task
             Projection(_) => None,           // @Task
             IO(_) => None,                   // @Task
+            Panic(_) => None,                // @Task
             Error => None,                   // @Task
         }
     }