Make get_children an iterator

crates/cairo-lang-defs/src/cache/mod.rs

@@ -1635,7 +1635,7 @@ impl SyntaxNodeIdCached {
             SyntaxNodeId::Root(file_id) => Self::Root(FileIdCached::new(*file_id, ctx)),
             SyntaxNodeId::Child { parent, key_fields, index } => Self::Child {
                 parent: SyntaxNodeCached::new(*parent, ctx),
-                key_fields: key_fields.into_iter().map(|id| GreenIdCached::new(*id, ctx)).collect(),
+                key_fields: key_fields.iter().map(|id| GreenIdCached::new(*id, ctx)).collect(),
                 index: *index,
             },
         }
@@ -1646,7 +1646,9 @@ impl SyntaxNodeIdCached {
             SyntaxNodeIdCached::Root(file_id) => SyntaxNodeId::Root(file_id.embed(ctx)),
             SyntaxNodeIdCached::Child { parent, key_fields, index } => SyntaxNodeId::Child {
                 parent: parent.embed(ctx),
-                key_fields: Box::from_iter(key_fields.iter().map(|id| id.embed(ctx))),
+                key_fields: cairo_lang_syntax::node::ids::ArcGreenIds {
+                    ids: Arc::from_iter(key_fields.iter().map(|id| id.embed(ctx))),
+                },
                 index: *index,
             },
         }

crates/cairo-lang-defs/src/patcher.rs

@@ -65,55 +65,52 @@ impl<'db> RewriteNode<'db> {
         match self {
             RewriteNode::Copied(syntax_node) => {
                 *self = RewriteNode::new_modified(
-                    syntax_node.get_children(db).iter().copied().map(RewriteNode::Copied).collect(),
+                    syntax_node.get_children(db).map(RewriteNode::Copied).collect(),
                 );
                 extract_matches!(self, RewriteNode::Modified)
             }
             RewriteNode::Trimmed { node, trim_left, trim_right } => {
-                let children = node.get_children(db);
+                let mut children = node.get_children(db).enumerate();
                 let num_children = children.len();
                 let mut new_children = Vec::new();
 
                 // Get the index of the leftmost nonempty child.
-                let Some(left_idx) =
-                    children.iter().position(|child| child.width(db) != TextWidth::default())
+                let Some((left_idx, first_syntax)) =
+                    children.find(|(_, child)| child.width(db) != TextWidth::default())
                 else {
                     *self = RewriteNode::Modified(ModifiedNode { children: None });
                     return extract_matches!(self, RewriteNode::Modified);
                 };
                 // Get the index of the rightmost nonempty child.
-                let right_idx = children
-                    .iter()
-                    .rposition(|child| child.width(db) != TextWidth::default())
-                    .unwrap();
+                let (right_idx, last_syntax) = children
+                    .rfind(|(_, child)| child.width(db) != TextWidth::default())
+                    .unwrap_or((left_idx, first_syntax));
                 new_children.extend(itertools::repeat_n(
                     RewriteNode::Modified(ModifiedNode { children: None }),
                     left_idx,
                 ));
 
                 // The number of children between the first and last nonempty nodes.
                 let num_middle = right_idx - left_idx + 1;
-                let mut children_iter = children.iter().skip(left_idx);
                 match num_middle {
                     1 => {
                         new_children.push(RewriteNode::Trimmed {
-                            node: *children_iter.next().unwrap(),
+                            node: first_syntax,
                             trim_left: *trim_left,
                             trim_right: *trim_right,
                         });
                     }
                     _ => {
                         new_children.push(RewriteNode::Trimmed {
-                            node: *children_iter.next().unwrap(),
+                            node: first_syntax,
                             trim_left: *trim_left,
                             trim_right: false,
                         });
-                        for _ in 0..(num_middle - 2) {
-                            let child = *children_iter.next().unwrap();
+                        for (_, child) in children {
                             new_children.push(RewriteNode::Copied(child));
                         }
                         new_children.push(RewriteNode::Trimmed {
-                            node: *children_iter.next().unwrap(),
+                            node: last_syntax,
                             trim_left: false,
                             trim_right: *trim_right,
                         });

crates/cairo-lang-defs/src/test.rs

@@ -92,8 +92,8 @@ fn test_generic_item_id(
             }
             _ => {}
         }
-        for child in node.get_children(db).iter() {
-            find_generics(db, module_id, child, output);
+        for child in node.get_children(db) {
+            find_generics(db, module_id, &child, output);
         }
     }
     find_generics(&db_val, module_id, &file_syntax.as_syntax_node(), &mut output);

crates/cairo-lang-doc/src/documentable_formatter.rs

@@ -865,7 +865,7 @@ fn write_function_signature<'db>(
 
 /// Retrieves [`SyntaxKind::TypeClause`] text from [`SyntaxNode`].
 fn get_type_clause<'db>(syntax_node: SyntaxNode<'db>, db: &'db dyn Database) -> Option<String> {
-    for child in syntax_node.get_children(db).iter() {
+    for child in syntax_node.get_children(db) {
         if child.kind(db) == SyntaxKind::TypeClause {
             return Some(child.get_text_without_all_comment_trivia(db));
         }
@@ -959,7 +959,7 @@ fn write_struct_attributes_syntax<'db>(
 ) -> Result<(), fmt::Error> {
     for attribute in attributes {
         let syntax_node = attribute.stable_ptr.lookup(f.db).as_syntax_node();
-        for child in syntax_node.get_children(f.db).iter() {
+        for child in syntax_node.get_children(f.db) {
             let to_text = child.get_text_without_all_comment_trivia(f.db);
             let cleaned_text = to_text.replace("\n", "");
             f.write_str(&cleaned_text)?;
@@ -978,7 +978,7 @@ fn write_syntactic_evaluation<'db>(
         let syntax_node = stable_location.syntax_node(f.db);
         if matches!(&syntax_node.green_node(f.db).details, green::GreenNodeDetails::Node { .. }) {
             let mut is_after_evaluation_value = false;
-            for child in syntax_node.get_children(f.db).iter() {
+            for child in syntax_node.get_children(f.db) {
                 let kind = child.kind(f.db);
                 if !matches!(kind, SyntaxKind::Trivia) {
                     if matches!(kind, SyntaxKind::TerminalSemicolon) {
@@ -987,7 +987,7 @@ fn write_syntactic_evaluation<'db>(
                     }
                     if is_after_evaluation_value {
                         f.buf.write_str(&SyntaxNode::get_text_without_all_comment_trivia(
-                            child, f.db,
+                            &child, f.db,
                         ))?;
                     };
                     if matches!(kind, SyntaxKind::TerminalEq) {

crates/cairo-lang-doc/src/location_links.rs

@@ -36,8 +36,8 @@ fn collect_green_nodes<'db>(
         GreenNodeDetails::Token(text) => green_nodes.push((green_node.kind, text.to_string(db))),
         GreenNodeDetails::Node { .. } => {
             let syntax_node_children = syntax_node.get_children(db);
-            syntax_node_children.iter().for_each(|child| {
-                collect_green_nodes(db, child, green_nodes);
+            syntax_node_children.for_each(|child| {
+                collect_green_nodes(db, &child, green_nodes);
             });
         }
     }

crates/cairo-lang-formatter/src/formatter_impl.rs

@@ -1033,7 +1033,7 @@ impl<'a> FormatterImpl<'a> {
         let internal_break_line_points_positions =
             syntax_node.get_internal_break_line_point_properties(self.db, &self.config);
         // TODO(ilya): consider not copying here.
-        let mut children = syntax_node.get_children(self.db).to_vec();
+        let mut children: Vec<_> = syntax_node.get_children(self.db).collect();
         let n_children = children.len();
 
         if self.config.merge_use_items {
@@ -1118,8 +1118,8 @@ impl<'a> FormatterImpl<'a> {
                 );
 
                 // Add merged children to the new_children list.
-                if let Some(child) = merged_node.get_children(self.db).iter().next() {
-                    new_children.extend(child.get_children(self.db).iter().copied());
+                if let Some(child) = merged_node.get_children(self.db).next() {
+                    new_children.extend(child.get_children(self.db));
                 }
             }
         }
@@ -1212,15 +1212,16 @@ impl<'a> FormatterImpl<'a> {
     fn format_terminal(&mut self, syntax_node: &SyntaxNode<'a>) {
         // TODO(spapini): Introduce a Terminal and a Token enum in ast.rs to make this cleaner.
         let children = syntax_node.get_children(self.db);
-        let [leading, token, trailing] = children else {
+        let Some([leading, token, trailing]) = children.collect_array() else {
             panic!("Terminal node should have 3 children.");
         };
+
         // The first newlines is the leading trivia correspond exactly to empty lines.
-        self.format_trivia(ast::Trivia::from_syntax_node(self.db, *leading), true);
+        self.format_trivia(ast::Trivia::from_syntax_node(self.db, leading), true);
         if !syntax_node.should_skip_terminal(self.db) {
-            self.format_token(token);
+            self.format_token(&token);
         }
-        self.format_trivia(ast::Trivia::from_syntax_node(self.db, *trailing), false);
+        self.format_trivia(ast::Trivia::from_syntax_node(self.db, trailing), false);
     }
     /// Appends a trivia node (if needed) to the result.
     fn format_trivia(&mut self, trivia: syntax::node::ast::Trivia<'a>, is_leading: bool) {

crates/cairo-lang-formatter/src/node_properties.rs

@@ -140,7 +140,6 @@ impl<'a> SyntaxNodeFormat for SyntaxNode<'a> {
                         .parent(db)
                         .unwrap()
                         .get_children(db)
-                        .iter()
                         .any(|c| c.kind(db) == SyntaxKind::PatternEnumInnerPattern) =>
             {
                 true
@@ -931,8 +930,6 @@ impl<'a> SyntaxNodeFormat for SyntaxNode<'a> {
     }
 
     fn should_skip_terminal(&self, db: &dyn Database) -> bool {
-        let is_last =
-            |node: &SyntaxNode<'_>, siblings: &[SyntaxNode<'_>]| siblings.last() == Some(node);
         // Check for TerminalComma with specific conditions on list types and position.
         if self.kind(db) == SyntaxKind::TerminalComma
             && matches!(
@@ -963,7 +960,7 @@ impl<'a> SyntaxNodeFormat for SyntaxNode<'a> {
             );
             if (!is_expr_or_pattern_list || children.len() > 2)
             // Ensure that this node is the last element in the list.
-            && is_last(self, children)
+            && children.last() == Some(*self)
             {
                 return true;
             }
@@ -978,11 +975,11 @@ impl<'a> SyntaxNodeFormat for SyntaxNode<'a> {
             let statements_node = statement_node.parent(db).unwrap();
             // Checking if not the last statement, as `;` may be there to prevent the block from
             // returning the value of the current block.
-            let not_last = !is_last(&statement_node, statements_node.get_children(db));
-            let children = statement_node.get_children(db);
+            let statements_children = statements_node.get_children(db);
+            let not_last = statements_children.last() != Some(statement_node);
             if not_last
                 && matches!(
-                    children[1].kind(db),
+                    statement_node.get_child(db, 1).kind(db),
                     SyntaxKind::ExprBlock
                         | SyntaxKind::ExprIf
                         | SyntaxKind::ExprMatch
@@ -999,7 +996,7 @@ impl<'a> SyntaxNodeFormat for SyntaxNode<'a> {
         {
             let path_segment_node = self.parent(db).unwrap();
             let path_node = path_segment_node.parent(db).unwrap();
-            if !is_last(&path_segment_node, path_node.get_children(db)) {
+            if path_node.get_children(db).last() != Some(path_segment_node) {
                 false
             } else {
                 matches!(

crates/cairo-lang-parser/src/colored_printer.rs

@@ -28,8 +28,8 @@ impl ColoredPrinter<'_> {
                 } else if self.verbose && is_empty_kind(node.kind) {
                     self.result.push_str(format!("{}", "<e>".red()).as_str());
                 } else {
-                    for child in syntax_node.get_children(self.db).iter() {
-                        self.print(child);
+                    for child in syntax_node.get_children(self.db) {
+                        self.print(&child);
                     }
                 }
             }

crates/cairo-lang-parser/src/printer.rs

@@ -209,29 +209,29 @@ impl<'a> Printer<'a> {
             NodeKind::Struct { members: expected_children }
             | NodeKind::Terminal { members: expected_children, .. } => {
                 self.print_internal_struct(
-                    children,
+                    syntax_node.get_children(self.db),
                     &expected_children,
                     indent.as_str(),
                     under_top_level,
                 );
             }
             NodeKind::List { .. } => {
-                for (i, child) in children.iter().enumerate() {
+                for (i, child) in syntax_node.get_children(self.db).enumerate() {
                     self.print_tree(
                         format!("child #{i}").as_str(),
-                        child,
+                        &child,
                         indent.as_str(),
                         i == num_children - 1,
                         under_top_level,
                     );
                 }
             }
             NodeKind::SeparatedList { .. } => {
-                for (i, child) in children.iter().enumerate() {
+                for (i, child) in syntax_node.get_children(self.db).enumerate() {
                     let description = if i.is_multiple_of(2) { "item" } else { "separator" };
                     self.print_tree(
                         format!("{description} #{}", i / 2).as_str(),
-                        child,
+                        &child,
                         indent.as_str(),
                         i == num_children - 1,
                         under_top_level,
@@ -244,20 +244,20 @@ impl<'a> Printer<'a> {
 
     /// Assumes children and expected children are non-empty of the same length.
     /// `under_top_level`: whether we are in a subtree of the top-level kind.
-    fn print_internal_struct(
+    fn print_internal_struct<'b>(
         &mut self,
-        children: &[SyntaxNode<'_>],
+        mut children: impl ExactSizeIterator<Item = SyntaxNode<'b>> + DoubleEndedIterator,
         expected_children: &[Member],
         indent: &str,
         under_top_level: bool,
     ) {
-        let (last_child, non_last_children) = children.split_last().unwrap();
-        let (last_expected_child, non_last_expected_children) =
-            expected_children.split_last().unwrap();
-        for (child, expected_child) in zip_eq(non_last_children, non_last_expected_children) {
-            self.print_tree(&expected_child.name, child, indent, false, under_top_level);
+        let mut expected_children = expected_children.iter();
+        let last_child = children.next_back().unwrap();
+        let last_expected_child = expected_children.next_back().unwrap();
+        for (child, expected_child) in zip_eq(children, expected_children) {
+            self.print_tree(&expected_child.name, &child, indent, false, under_top_level);
         }
-        self.print_tree(&last_expected_child.name, last_child, indent, true, under_top_level);
+        self.print_tree(&last_expected_child.name, &last_child, indent, true, under_top_level);
     }
 
     fn get_node_kind(&self, name: String) -> NodeKind {

crates/cairo-lang-plugins/src/plugins/generate_trait.rs

@@ -184,8 +184,8 @@ fn generate_trait_for_impl<'db>(
                         builder.add_node(decl.name(db).as_syntax_node());
                         builder.add_node(decl.generic_params(db).as_syntax_node());
                         builder.add_node(signature.lparen(db).as_syntax_node());
-                        for node in signature.parameters(db).node.get_children(db).iter() {
-                            if let Some(param) = ast::Param::cast(db, *node) {
+                        for node in signature.parameters(db).node.get_children(db) {
+                            if let Some(param) = ast::Param::cast(db, node) {
                                 for modifier in param.modifiers(db).elements(db) {
                                     // `mut` modifiers are only relevant for impls, not traits.
                                     if !matches!(modifier, ast::Modifier::Mut(_)) {
@@ -195,7 +195,7 @@ fn generate_trait_for_impl<'db>(
                                 builder.add_node(param.name(db).as_syntax_node());
                                 builder.add_node(param.type_clause(db).as_syntax_node());
                             } else {
-                                builder.add_node(*node);
+                                builder.add_node(node);
                             }
                         }
                         let rparen = signature.rparen(db);

crates/cairo-lang-semantic/src/items/macro_declaration.rs

@@ -227,8 +227,8 @@ fn collect_expansion_placeholders<'db>(
         return placeholders;
     }
     if !node.kind(db).is_terminal() {
-        for child in node.get_children(db).iter() {
-            placeholders.extend(collect_expansion_placeholders(db, *child));
+        for child in node.get_children(db) {
+            placeholders.extend(collect_expansion_placeholders(db, child));
         }
     }
     placeholders
@@ -571,8 +571,8 @@ fn expand_macro_rule_ex(
                 return Ok(());
             }
 
-            for child in node.get_children(db).iter() {
-                expand_macro_rule_ex(db, *child, matcher_ctx, res_buffer, code_mappings)?;
+            for child in node.get_children(db) {
+                expand_macro_rule_ex(db, child, matcher_ctx, res_buffer, code_mappings)?;
             }
             return Ok(());
         }
@@ -581,8 +581,8 @@ fn expand_macro_rule_ex(
         res_buffer.push_str(node.get_text(db));
         return Ok(());
     }
-    for child in node.get_children(db).iter() {
-        expand_macro_rule_ex(db, *child, matcher_ctx, res_buffer, code_mappings)?;
+    for child in node.get_children(db) {
+        expand_macro_rule_ex(db, child, matcher_ctx, res_buffer, code_mappings)?;
     }
     Ok(())
 }

crates/cairo-lang-starknet/src/plugin/starknet_module/contract.rs

@@ -792,9 +792,9 @@ fn try_extract_named_macro_argument<'db>(
                         return Some(path);
                     }
                     let segments = path.segments(db);
-                    let mut elements = segments.elements(db);
+                    let elements = segments.elements(db);
                     if elements.len() != 1
-                        || !matches!(elements.next_back().unwrap(), ast::PathSegment::Simple(_))
+                        || !matches!(elements.last().unwrap(), ast::PathSegment::Simple(_))
                     {
                         diagnostics.push(PluginDiagnostic::error_with_inner_span(
                             db,

crates/cairo-lang-syntax-codegen/src/generator.rs

@@ -617,7 +617,7 @@ fn gen_struct_code(name: String, members: Vec<Member>, is_terminal: bool) -> rus
         params.extend(quote! {$name: $(&child_green)<'db>,});
         body.extend(quote! {
             pub fn $name(&self, db: &'db dyn Database) -> $kind<'db> {
-                $kind::from_syntax_node(db, self.node.get_children(db)[$i])
+                $kind::from_syntax_node(db, self.node.get_child(db, $i))
             }
         });
         args_for_missing.extend(quote! {$kind::missing(db).0,});