feat: compile Endor await expressions through the source pipeline

crates/frontend/src/ast/generated.rs

@@ -3,7 +3,7 @@
 use super::Spanned;
 use crate::Span;
 pub const AST_SCHEMA_ID: &str =
-    "urn:endor:ast:sha256:ad2ac52943dd26e08395c0d2698861da98bb89c360241c4712c769de86709fd0";
+    "urn:endor:ast:sha256:c7c10c6a61158810fa55044f1aa79f3558ac18ca3be59cbf7f2499b5add8df5b";
 #[derive(Debug, Clone, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
 #[serde(deny_unknown_fields)]
 pub struct AstDocument {
@@ -234,6 +234,7 @@ pub enum ExprKind {
     Number(String),
     String(String),
     Symbol(Name),
+    Await(Box<Expr>),
     Unary {
         operation: UnaryOp,
         operand: Box<Expr>,

crates/frontend/src/ast/visitor.rs

@@ -316,6 +316,9 @@ pub fn walk_expr_kind<V: Visitor + ?Sized>(
         ExprKind::Symbol(value) => {
             visitor.visit_name(value)?;
         }
+        ExprKind::Await(value) => {
+            visitor.visit_expr(value)?;
+        }
         ExprKind::Unary {
             operation, operand, ..
         } => {

crates/frontend/src/grammar.peg

@@ -146,6 +146,9 @@ peg::parser! {
             left:(@) star() right:@ { binary(left, BinaryOp::Multiply, right) }
             left:(@) slash() right:@ { binary(left, BinaryOp::Divide, right) }
             --
+            start:keyword("await") operand:@ {
+                Expr { span: start.through(operand.span), kind: ExprKind::Await { operand: Box::new(operand) } }
+            }
             start:minus() operand:@ {
                 Expr { span: start.through(operand.span), kind: ExprKind::Unary { operation: UnaryOp::Negate, operand: Box::new(operand) } }
             }