cl-ast: Move loop expression into unary exprs (with lowest priority)

compiler/cl-ast/src/ast.rs

@@ -392,8 +392,6 @@ pub enum ExprKind {
     Group(Group),
     /// A [Tuple] expression: `(` [`Expr`] (`,` [`Expr`])+ `)`
     Tuple(Tuple),
-    /// A [Loop] expression: `loop` [`Block`]
-    Loop(Loop),
     /// A [While] expression: `while` [`Expr`] [`Block`] [`Else`]?
     While(While),
     /// An [If] expression: `if` [`Expr`] [`Block`] [`Else`]?
@@ -482,6 +480,8 @@ pub enum UnaryKind {
     Deref,
     Neg,
     Not,
+    /// A Loop expression: `loop` [`Block`]
+    Loop,
     /// Unused
     At,
     /// Unused
@@ -570,12 +570,6 @@ pub struct Tuple {
     pub exprs: Vec<Expr>,
 }
 
-/// A [Loop] expression: `loop` [`Block`]
-#[derive(Clone, Debug, PartialEq, Eq, Hash)]
-pub struct Loop {
-    pub body: Box<Expr>,
-}
-
 /// A [While] expression: `while` [`Expr`] [`Block`] [`Else`]?
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct While {

compiler/cl-ast/src/ast_impl.rs

@@ -448,7 +448,6 @@ mod display {
                 ExprKind::Block(v) => v.fmt(f),
                 ExprKind::Group(v) => v.fmt(f),
                 ExprKind::Tuple(v) => v.fmt(f),
-                ExprKind::Loop(v) => v.fmt(f),
                 ExprKind::While(v) => v.fmt(f),
                 ExprKind::If(v) => v.fmt(f),
                 ExprKind::For(v) => v.fmt(f),
@@ -542,6 +541,7 @@ mod display {
     impl Display for UnaryKind {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             match self {
+                UnaryKind::Loop => "loop ",
                 UnaryKind::Deref => "*",
                 UnaryKind::Neg => "-",
                 UnaryKind::Not => "!",
@@ -644,13 +644,6 @@ mod display {
         }
     }
 
-    impl Display for Loop {
-        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            let Self { body } = self;
-            write!(f, "loop {body}")
-        }
-    }
-
     impl Display for While {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
             let Self { cond, pass, fail } = self;
@@ -786,7 +779,6 @@ mod convert {
             Block => ExprKind::Block,
             Group => ExprKind::Group,
             Tuple => ExprKind::Tuple,
-            Loop => ExprKind::Loop,
             While => ExprKind::While,
             If => ExprKind::If,
             For => ExprKind::For,

compiler/cl-ast/src/ast_visitor/fold.rs

@@ -339,10 +339,6 @@ pub trait Fold {
         let Tuple { exprs } = t;
         Tuple { exprs: exprs.into_iter().map(|e| self.fold_expr(e)).collect() }
     }
-    fn fold_loop(&mut self, l: Loop) -> Loop {
-        let Loop { body } = l;
-        Loop { body: Box::new(self.fold_expr(*body)) }
-    }
     fn fold_while(&mut self, w: While) -> While {
         let While { cond, pass, fail } = w;
         While {
@@ -552,7 +548,6 @@ pub fn or_fold_expr_kind<F: Fold + ?Sized>(folder: &mut F, kind: ExprKind) -> Ex
         ExprKind::Block(b) => ExprKind::Block(folder.fold_block(b)),
         ExprKind::Group(g) => ExprKind::Group(folder.fold_group(g)),
         ExprKind::Tuple(t) => ExprKind::Tuple(folder.fold_tuple(t)),
-        ExprKind::Loop(l) => ExprKind::Loop(folder.fold_loop(l)),
         ExprKind::While(w) => ExprKind::While(folder.fold_while(w)),
         ExprKind::If(i) => ExprKind::If(folder.fold_if(i)),
         ExprKind::For(f) => ExprKind::For(folder.fold_for(f)),

compiler/cl-ast/src/ast_visitor/visit.rs

@@ -297,10 +297,6 @@ pub trait Visit<'a>: Sized {
         let Tuple { exprs } = t;
         exprs.iter().for_each(|e| self.visit_expr(e))
     }
-    fn visit_loop(&mut self, l: &'a Loop) {
-        let Loop { body } = l;
-        self.visit_expr(body)
-    }
     fn visit_while(&mut self, w: &'a While) {
         let While { cond, pass, fail } = w;
         self.visit_expr(cond);
@@ -476,7 +472,6 @@ pub fn or_visit_expr_kind<'a, V: Visit<'a>>(visitor: &mut V, e: &'a ExprKind) {
         ExprKind::Block(b) => visitor.visit_block(b),
         ExprKind::Group(g) => visitor.visit_group(g),
         ExprKind::Tuple(t) => visitor.visit_tuple(t),
-        ExprKind::Loop(l) => visitor.visit_loop(l),
         ExprKind::While(w) => visitor.visit_while(w),
         ExprKind::If(i) => visitor.visit_if(i),
         ExprKind::For(f) => visitor.visit_for(f),

compiler/cl-ast/src/desugar/while_else.rs

@@ -26,8 +26,8 @@ fn desugar_while(extents: Span, kind: ExprKind) -> ExprKind {
             let break_expr = Expr { extents: fail_span, kind: ExprKind::Break(Break { body }) };
 
             let loop_body = If { cond, pass, fail: Else { body: Some(Box::new(break_expr)) } };
-            let loop_body = Expr { extents, kind: ExprKind::If(loop_body) };
-            ExprKind::Loop(Loop { body: Box::new(loop_body) })
+            let loop_body = ExprKind::If(loop_body);
+            ExprKind::Unary(Unary { kind: UnaryKind::Loop, tail: Box::new(loop_body) })
         }
         _ => kind,
     }