storing comments in a singleton

Author: Janther

src/slang-nodes/PositionalArgumentsDeclaration.ts

@@ -27,9 +27,11 @@ export class PositionalArgumentsDeclaration extends SlangNode {
 
     // We need to check the comments at this point because they will be removed
     // from this node into the root node.
+    // Since we are collecting comments in a different array, we have to query
+    // the ast directly for possible block comments.
     this.isEmpty =
       this.arguments.items.length === 0 && // no arguments
-      !this.comments.some((comment) => isBlockComment(comment)); // no block comments
+      !ast.cst.children().some(({ node }) => isBlockComment(node)); // no block comments
   }
 
   print(

src/slang-nodes/SlangNode.ts

@@ -12,10 +12,16 @@ import type { Comment, StrictAstNode } from '../slang-nodes/types.d.ts';
 import type { AstLocation, SlangAstNode } from '../types.d.ts';
 
 const offsets = new Map<number, number>();
+const comments: Comment[] = [];
+
 export function clearOffsets(): void {
   offsets.clear();
 }
 
+export function clearComments(): Comment[] {
+  return comments.splice(0);
+}
+
 function reversedIterator<T>(children: T[]): Iterable<T> {
   return {
     [Symbol.iterator](): Iterator<T> {
@@ -30,21 +36,6 @@ function reversedIterator<T>(children: T[]): Iterable<T> {
   };
 }
 
-function collectComments(
-  comments: Comment[],
-  node: StrictAstNode | StrictAstNode[] | undefined
-): Comment[] {
-  if (node) {
-    if (Array.isArray(node)) {
-      return node.reduce(collectComments, comments);
-    }
-    if (node.comments.length > 0) {
-      comments.push(...node.comments.splice(0));
-    }
-  }
-  return comments;
-}
-
 export class SlangNode {
   comments: Comment[] = [];
 
@@ -98,16 +89,16 @@ export class SlangNode {
           // offset, it's hard to separate these responsibilities into different
           // functions without doing the iteration twice.
           case TerminalKind.MultiLineComment:
-            this.comments.push(new MultiLineComment(node, offset));
+            comments.push(new MultiLineComment(node, offset));
             break;
           case TerminalKind.MultiLineNatSpecComment:
-            this.comments.push(new MultiLineNatSpecComment(node, offset));
+            comments.push(new MultiLineNatSpecComment(node, offset));
             break;
           case TerminalKind.SingleLineComment:
-            this.comments.push(new SingleLineComment(node, offset));
+            comments.push(new SingleLineComment(node, offset));
             break;
           case TerminalKind.SingleLineNatSpecComment:
-            this.comments.push(new SingleLineNatSpecComment(node, offset));
+            comments.push(new SingleLineNatSpecComment(node, offset));
             break;
         }
         // We accumulate the trivia length
@@ -133,10 +124,7 @@ export class SlangNode {
   updateMetadata(
     ...childNodes: (StrictAstNode | StrictAstNode[] | undefined)[]
   ): void {
-    const { comments, loc } = this;
-    // Collect comments
-    this.comments = childNodes.reduce(collectComments, comments);
-
+    const { loc } = this;
     // calculate correct loc object
     if (loc.leadingOffset === 0) {
       for (const childNode of childNodes) {

src/slang-nodes/SourceUnit.ts

@@ -21,10 +21,6 @@ export class SourceUnit extends SlangNode {
     this.members = new SourceUnitMembers(ast.members, options);
 
     this.updateMetadata(this.members);
-
-    // Because of comments being extracted like a russian doll, the order needs
-    // to be fixed at the end.
-    this.comments = this.comments.sort((a, b) => a.loc.start - b.loc.start);
   }
 
   print(

src/slangSolidityParser.ts

@@ -1,6 +1,6 @@
 // https://prettier.io/docs/en/plugins.html#parsers
 import { SourceUnit as SlangSourceUnit } from '@nomicfoundation/slang/ast';
-import { clearOffsets } from './slang-nodes/SlangNode.js';
+import { clearOffsets, clearComments } from './slang-nodes/SlangNode.js';
 import { createParser } from './slang-utils/create-parser.js';
 import { SourceUnit } from './slang-nodes/SourceUnit.js';
 
@@ -19,6 +19,10 @@ export default function parse(
     new SlangSourceUnit(parseOutput.tree.asNonterminalNode()),
     options
   );
+
+  // Because of comments being extracted like a russian doll, the order needs
+  // to be fixed at the end.
+  parsed.comments = clearComments().sort((a, b) => a.loc.start - b.loc.start);
   clearOffsets();
   return parsed;
 }