Merge df78e0a into 3047ed6

boa/src/syntax/ast/keyword.rs

@@ -36,6 +36,16 @@ pub enum Keyword {
     /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/await
     Await,
 
+    /// The `async` keyword.
+    ///
+    /// More information:
+    ///  - [ECMAScript reference][spec]
+    ///  - [MDN documentation][mdn]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#prod-AsyncMethod
+    /// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/async_function
+    Async,
+
     /// The `break` keyword.
     ///
     /// More information:
@@ -454,6 +464,7 @@ impl Keyword {
     pub fn as_str(self) -> &'static str {
         match self {
             Self::Await => "await",
+            Self::Async => "async",
             Self::Break => "break",
             Self::Case => "case",
             Self::Catch => "catch",
@@ -526,6 +537,7 @@ impl FromStr for Keyword {
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         match s {
             "await" => Ok(Self::Await),
+            "async" => Ok(Self::Async),
             "break" => Ok(Self::Break),
             "case" => Ok(Self::Case),
             "catch" => Ok(Self::Catch),

boa/src/syntax/ast/node/await_expr/mod.rs

@@ -0,0 +1,61 @@
+//! Await expression node.
+
+use super::Node;
+use crate::{exec::Executable, BoaProfiler, Context, Result, Value};
+use gc::{Finalize, Trace};
+use std::fmt;
+
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
+/// An await expression is used within an async function to pause execution and wait for a
+/// promise to resolve.
+///
+/// More information:
+///  - [ECMAScript reference][spec]
+///  - [MDN documentation][mdn]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-AwaitExpression
+/// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/await
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[derive(Clone, Debug, Trace, Finalize, PartialEq)]
+pub struct AwaitExpr {
+    expr: Box<Node>,
+}
+
+impl Executable for AwaitExpr {
+    fn run(&self, _: &mut Context) -> Result<Value> {
+        let _timer = BoaProfiler::global().start_event("AwaitExpression", "exec");
+        // TODO: Implement AwaitExpr
+        Ok(Value::Undefined)
+    }
+}
+
+impl AwaitExpr {
+    /// Implements the display formatting with indentation.
+    pub(super) fn display(&self, f: &mut fmt::Formatter<'_>, indentation: usize) -> fmt::Result {
+        writeln!(f, "await ")?;
+        self.expr.display(f, indentation)
+    }
+}
+
+impl<T> From<T> for AwaitExpr
+where
+    T: Into<Box<Node>>,
+{
+    fn from(e: T) -> Self {
+        Self { expr: e.into() }
+    }
+}
+
+impl fmt::Display for AwaitExpr {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.display(f, 0)
+    }
+}
+
+impl From<AwaitExpr> for Node {
+    fn from(awaitexpr: AwaitExpr) -> Self {
+        Self::AwaitExpr(awaitexpr)
+    }
+}

boa/src/syntax/ast/node/declaration/async_function_decl/mod.rs

@@ -0,0 +1,101 @@
+//! Async Function Declaration.
+
+use crate::{
+    exec::Executable,
+    syntax::ast::node::{join_nodes, FormalParameter, Node, StatementList},
+    BoaProfiler, Context, Result, Value,
+};
+use gc::{Finalize, Trace};
+use std::fmt;
+
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
+/// An async function is used to specify an action (or series of actions) to perform asynchronously.
+///
+/// More information:
+///  - [ECMAScript reference][spec]
+///  - [MDN documentation][mdn]
+///
+/// [spec]: https://tc39.es/ecma262/#sec-async-function-prototype-properties
+/// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/async_function
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[derive(Clone, Debug, Trace, Finalize, PartialEq)]
+pub struct AsyncFunctionDecl {
+    name: Option<Box<str>>,
+    parameters: Box<[FormalParameter]>,
+    body: StatementList,
+}
+
+impl AsyncFunctionDecl {
+    /// Creates a new async function declaration.
+    pub(in crate::syntax) fn new<N, P, B>(name: N, parameters: P, body: B) -> Self
+    where
+        N: Into<Option<Box<str>>>,
+        P: Into<Box<[FormalParameter]>>,
+        B: Into<StatementList>,
+    {
+        Self {
+            name: name.into(),
+            parameters: parameters.into(),
+            body: body.into(),
+        }
+    }
+
+    /// Gets the name of the async function declaration.
+    pub fn name(&self) -> Option<&str> {
+        self.name.as_deref()
+    }
+
+    /// Gets the list of parameters of the async function declaration.
+    pub fn parameters(&self) -> &[FormalParameter] {
+        &self.parameters
+    }
+
+    /// Gets the body of the async function declaration.
+    pub fn body(&self) -> &[Node] {
+        self.body.statements()
+    }
+
+    /// Implements the display formatting with indentation.
+    pub(in crate::syntax::ast::node) fn display(
+        &self,
+        f: &mut fmt::Formatter<'_>,
+        indentation: usize,
+    ) -> fmt::Result {
+        match &self.name {
+            Some(name) => {
+                write!(f, "async function {}(", name)?;
+            }
+            None => {
+                write!(f, "async function (")?;
+            }
+        }
+        join_nodes(f, &self.parameters)?;
+        f.write_str(") {{")?;
+
+        self.body.display(f, indentation + 1)?;
+
+        writeln!(f, "}}")
+    }
+}
+
+impl Executable for AsyncFunctionDecl {
+    fn run(&self, _: &mut Context) -> Result<Value> {
+        let _timer = BoaProfiler::global().start_event("AsyncFunctionDecl", "exec");
+        // TODO: Implement AsyncFunctionDecl
+        Ok(Value::undefined())
+    }
+}
+
+impl From<AsyncFunctionDecl> for Node {
+    fn from(decl: AsyncFunctionDecl) -> Self {
+        Self::AsyncFunctionDecl(decl)
+    }
+}
+
+impl fmt::Display for AsyncFunctionDecl {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.display(f, 0)
+    }
+}

boa/src/syntax/ast/node/declaration/async_function_expr/mod.rs

@@ -0,0 +1,98 @@
+//! Async Function Expression.
+
+use crate::{
+    exec::Executable,
+    syntax::ast::node::{join_nodes, FormalParameter, Node, StatementList},
+    Context, Result, Value,
+};
+use gc::{Finalize, Trace};
+use std::fmt;
+
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
+/// An async function expression is very similar to an async function declaration except used within
+/// a wider expression (for example during an assignment).
+///
+/// More information:
+///  - [ECMAScript reference][spec]
+///  - [MDN documentation][mdn]
+///
+/// [spec]: https://tc39.es/ecma262/#prod-AsyncFunctionExpression
+/// [mdn]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/async_function
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[derive(Clone, Debug, Trace, Finalize, PartialEq)]
+pub struct AsyncFunctionExpr {
+    name: Option<Box<str>>,
+    parameters: Box<[FormalParameter]>,
+    body: StatementList,
+}
+
+impl AsyncFunctionExpr {
+    /// Creates a new function expression
+    pub(in crate::syntax) fn new<N, P, B>(name: N, parameters: P, body: B) -> Self
+    where
+        N: Into<Option<Box<str>>>,
+        P: Into<Box<[FormalParameter]>>,
+        B: Into<StatementList>,
+    {
+        Self {
+            name: name.into(),
+            parameters: parameters.into(),
+            body: body.into(),
+        }
+    }
+
+    /// Gets the name of the function declaration.
+    pub fn name(&self) -> Option<&str> {
+        self.name.as_ref().map(Box::as_ref)
+    }
+
+    /// Gets the list of parameters of the function declaration.
+    pub fn parameters(&self) -> &[FormalParameter] {
+        &self.parameters
+    }
+
+    /// Gets the body of the function declaration.
+    pub fn body(&self) -> &[Node] {
+        self.body.statements()
+    }
+
+    /// Implements the display formatting with indentation.
+    pub(in crate::syntax::ast::node) fn display(
+        &self,
+        f: &mut fmt::Formatter<'_>,
+        indentation: usize,
+    ) -> fmt::Result {
+        f.write_str("function")?;
+        if let Some(ref name) = self.name {
+            write!(f, " {}", name)?;
+        }
+        f.write_str("(")?;
+        join_nodes(f, &self.parameters)?;
+        f.write_str(") {{")?;
+
+        self.body.display(f, indentation + 1)?;
+
+        writeln!(f, "}}")
+    }
+}
+
+impl Executable for AsyncFunctionExpr {
+    fn run(&self, _: &mut Context) -> Result<Value> {
+        // TODO: Implement AsyncFunctionExpr
+        Ok(Value::Undefined)
+    }
+}
+
+impl fmt::Display for AsyncFunctionExpr {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.display(f, 0)
+    }
+}
+
+impl From<AsyncFunctionExpr> for Node {
+    fn from(expr: AsyncFunctionExpr) -> Self {
+        Self::AsyncFunctionExpr(expr)
+    }
+}

boa/src/syntax/ast/node/declaration/mod.rs

@@ -1,6 +1,8 @@
 //! Declaration nodes
 
 pub mod arrow_function_decl;
+pub mod async_function_decl;
+pub mod async_function_expr;
 pub mod const_decl_list;
 pub mod function_decl;
 pub mod function_expr;
@@ -9,6 +11,8 @@ pub mod var_decl_list;
 
 pub use self::{
     arrow_function_decl::ArrowFunctionDecl,
+    async_function_decl::AsyncFunctionDecl,
+    async_function_expr::AsyncFunctionExpr,
     const_decl_list::{ConstDecl, ConstDeclList},
     function_decl::FunctionDecl,
     function_expr::FunctionExpr,

boa/src/syntax/ast/node/mod.rs

@@ -1,6 +1,7 @@
 //! This module implements the `Node` structure, which composes the AST.
 
 pub mod array;
+pub mod await_expr;
 pub mod block;
 pub mod break_node;
 pub mod call;
@@ -21,13 +22,14 @@ pub mod try_node;
 
 pub use self::{
     array::ArrayDecl,
+    await_expr::AwaitExpr,
     block::Block,
     break_node::Break,
     call::Call,
     conditional::{ConditionalOp, If},
     declaration::{
-        ArrowFunctionDecl, ConstDecl, ConstDeclList, FunctionDecl, FunctionExpr, LetDecl,
-        LetDeclList, VarDecl, VarDeclList,
+        ArrowFunctionDecl, AsyncFunctionDecl, AsyncFunctionExpr, ConstDecl, ConstDeclList,
+        FunctionDecl, FunctionExpr, LetDecl, LetDeclList, VarDecl, VarDeclList,
     },
     field::{GetConstField, GetField},
     identifier::Identifier,
@@ -65,6 +67,15 @@ pub enum Node {
     /// An assignment operator node. [More information](./operator/struct.Assign.html).
     Assign(Assign),
 
+    /// An async function declaration node. [More information](./declaration/struct.AsyncFunctionDecl.html).
+    AsyncFunctionDecl(AsyncFunctionDecl),
+
+    /// An async function expression node. [More information](./declaration/struct.AsyncFunctionExpr.html).
+    AsyncFunctionExpr(AsyncFunctionExpr),
+
+    /// An await expression node. [More information](./await_expr/struct.AwaitExpression.html).
+    AwaitExpr(AwaitExpr),
+
     /// A binary operator node. [More information](./operator/struct.BinOp.html).
     BinOp(BinOp),
 
@@ -104,7 +115,7 @@ pub enum Node {
     /// A function declaration node. [More information](./declaration/struct.FunctionDecl.html).
     FunctionDecl(FunctionDecl),
 
-    /// A function expressino node. [More information](./declaration/struct.FunctionExpr.html).
+    /// A function expression node. [More information](./declaration/struct.FunctionExpr.html).
     FunctionExpr(FunctionExpr),
 
     /// Provides access to an object types' constant properties. [More information](./declaration/struct.GetConstField.html).
@@ -243,6 +254,9 @@ impl Node {
             Self::Assign(ref op) => Display::fmt(op, f),
             Self::LetDeclList(ref decl) => Display::fmt(decl, f),
             Self::ConstDeclList(ref decl) => Display::fmt(decl, f),
+            Self::AsyncFunctionDecl(ref decl) => decl.display(f, indentation),
+            Self::AsyncFunctionExpr(ref expr) => expr.display(f, indentation),
+            Self::AwaitExpr(ref expr) => expr.display(f, indentation),
         }
     }
 }
@@ -251,6 +265,9 @@ impl Executable for Node {
     fn run(&self, interpreter: &mut Context) -> Result<Value> {
         let _timer = BoaProfiler::global().start_event("Executable", "exec");
         match *self {
+            Node::AsyncFunctionDecl(ref decl) => decl.run(interpreter),
+            Node::AsyncFunctionExpr(ref function_expr) => function_expr.run(interpreter),
+            Node::AwaitExpr(ref expr) => expr.run(interpreter),
             Node::Call(ref call) => call.run(interpreter),
             Node::Const(Const::Null) => Ok(Value::null()),
             Node::Const(Const::Num(num)) => Ok(Value::rational(num)),