support object rest destructuring in arrow functions

y21 · Dec 24, 2024 · 9abf963 · 9abf963
1 parent ff2e2cd
commit 9abf963
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Showing 3 changed files with 17 additions and 8 deletions.
diff --git a/crates/dash_middle/src/parser/error.rs b/crates/dash_middle/src/parser/error.rs
@@ -48,7 +48,7 @@ pub enum Error {
         expect: usize,
         token: Token,
     },
-    MultipleRestInDestructuring(Token),
+    MultipleRestInDestructuring(Span),
     RegexSyntaxError(Token, dash_regex::Error),
     IncompleteSpread(Token),
     /* Compiler */
@@ -311,7 +311,7 @@ impl fmt::Display for FormattableError<'_, '_> {
                 diag.message("incorrect number of parameters for accessor");
                 diag.span_error(span, format!("expected {expect}, got {got}"));
             }
-            Error::MultipleRestInDestructuring(Token { span, .. }) => {
+            Error::MultipleRestInDestructuring(span) => {
                 diag.message("multiple rest elements in destructuring");
                 diag.span_error(span, "second rest element defined here");
             }

diff --git a/crates/dash_parser/src/expr.rs b/crates/dash_parser/src/expr.rs
@@ -911,6 +911,7 @@ impl Parser<'_, '_> {
                 ExprKind::Object(ObjectLiteral(properties)) => {
                     let destructured_id = parser.local_count.inc();
                     let mut fields = Vec::with_capacity(properties.len());
+                    let mut rest = None;
                     for (key, value) in properties {
                         match key {
                             // `x: a` aliases x to 1
@@ -926,14 +927,22 @@ impl Parser<'_, '_> {
                             ObjectMemberKind::Default(symbol) => {
                                 fields.push((parser.local_count.inc(), symbol, None, Some(value)))
                             }
+                            ObjectMemberKind::Spread => {
+                                if rest.is_none() {
+                                    if let Some(symbol) = value.kind.as_identifier() {
+                                        rest = Some(parser.create_binding(symbol));
+                                    } else {
+                                        parser.error(Error::unexpected_token(value.span, TokenType::DUMMY_IDENTIFIER));
+                                    }
+                                } else {
+                                    parser.error(Error::MultipleRestInDestructuring(value.span))
+                                }
+                            }
                             _ => parser.error(Error::unexpected_token(value.span, TokenType::DUMMY_IDENTIFIER)),
                         }
                     }
 
-                    Some(Parameter::Pattern(destructured_id, Pattern::Object {
-                        fields,
-                        rest: None,
-                    }))
+                    Some(Parameter::Pattern(destructured_id, Pattern::Object { fields, rest }))
                 }
                 _ => {
                     parser.error(Error::Unimplemented(

diff --git a/crates/dash_parser/src/stmt.rs b/crates/dash_parser/src/stmt.rs
@@ -588,7 +588,7 @@ impl Parser<'_, '_> {
                         if let Some(sym) = name.ty.as_identifier() {
                             if rest.is_some() {
                                 // Only allow one rest operator
-                                self.error(Error::MultipleRestInDestructuring(name));
+                                self.error(Error::MultipleRestInDestructuring(name.span));
                                 return None;
                             }
 
@@ -665,7 +665,7 @@ impl Parser<'_, '_> {
                         if let Some(sym) = name.ty.as_identifier() {
                             if rest.is_some() {
                                 // Only allow one rest operator
-                                self.error(Error::MultipleRestInDestructuring(name));
+                                self.error(Error::MultipleRestInDestructuring(name.span));
                                 return None;
                             }