add attribute for skipping return checks

spec/index.html

@@ -212,6 +212,7 @@ <h1>Structured Headers</h1>
             <li><b>for:</b> The type of value to which a clause of type "concrete method" or "internal method" applies.</li>
             <li><b>redefinition:</b> If "true", the name of the operation will not automatically link (i.e., it will not automatically be given an aoid).</li>
             <li><b>skip global checks:</b> If "true", disables consistency checks for this AO which require knowing every callsite.</li>
+            <li><b>skip return checks:</b> If "true", disables checking that the returned values from this AO correspond to its declared return type.</li>
           </ul>
         </li>
       </ol>

src/Biblio.ts

@@ -271,8 +271,10 @@ export default class Biblio {
         delete copy.location;
         // @ts-ignore
         delete copy.referencingIds;
-        // @ts-ignore
-        delete copy._node;
+        for (const key of Object.keys(copy)) {
+          // @ts-ignore
+          if (key.startsWith('_')) delete copy[key];
+        }
         return copy;
       }),
     };
@@ -344,6 +346,7 @@ export interface AlgorithmBiblioEntry extends BiblioEntryBase {
   signature: null | Signature;
   effects: string[];
   skipGlobalChecks?: boolean;
+  /** @internal*/ _skipReturnChecks?: boolean;
   /** @internal*/ _node?: Element;
 }
 
@@ -398,7 +401,7 @@ export type PartialBiblioEntry = Unkey<BiblioEntry, NonExportedKeys>;
 
 export type ExportedBiblio = {
   location: string;
-  entries: PartialBiblioEntry[];
+  entries: Unkey<PartialBiblioEntry, `_${string}`>[];
 };
 
 function dumpEnv(env: EnvRec) {

src/Clause.ts

@@ -55,6 +55,7 @@ export default class Clause extends Builder {
   /** @internal */ readonly effects: string[]; // this is held by identity and mutated by Spec.ts
   /** @internal */ signature: Signature | null;
   /** @internal */ skipGlobalChecks: boolean;
+  /** @internal */ skipReturnChecks: boolean;
 
   constructor(spec: Spec, node: HTMLElement, parent: Clause, number: string) {
     super(spec, node);
@@ -67,6 +68,7 @@ export default class Clause extends Builder {
     this.examples = [];
     this.effects = [];
     this.skipGlobalChecks = false;
+    this.skipReturnChecks = false;
 
     // namespace is either the entire spec or the parent clause's namespace.
     let parentNamespace = spec.namespace;
@@ -206,6 +208,7 @@ export default class Clause extends Builder {
       effects,
       redefinition,
       skipGlobalChecks,
+      skipReturnChecks,
     } = parseStructuredHeaderDl(this.spec, type, dl);
 
     const paras = formatPreamble(
@@ -237,6 +240,7 @@ export default class Clause extends Builder {
     }
 
     this.skipGlobalChecks = skipGlobalChecks;
+    this.skipReturnChecks = skipReturnChecks;
 
     this.effects.push(...effects);
     for (const effect of effects) {
@@ -373,6 +377,7 @@ export default class Clause extends Builder {
           signature,
           effects: clause.effects,
           _node: clause.node,
+          _skipReturnChecks: clause.skipReturnChecks,
         };
         if (clause.skipGlobalChecks) {
           op.skipGlobalChecks = true;

src/header-parser.ts

@@ -407,12 +407,14 @@ export function parseStructuredHeaderDl(
   effects: string[];
   redefinition: boolean;
   skipGlobalChecks: boolean;
+  skipReturnChecks: boolean;
 } {
   let description = null;
   let _for = null;
   let redefinition: boolean | null = null;
   let effects: string[] = [];
   let skipGlobalChecks: boolean | null = null;
+  let skipReturnChecks: boolean | null = null;
   for (let i = 0; i < dl.children.length; ++i) {
     const dt = dl.children[i];
     if (dt.tagName !== 'DT') {
@@ -482,6 +484,7 @@ export function parseStructuredHeaderDl(
         }
         break;
       }
+      // TODO figure out how to de-dupe the code for boolean attributes
       case 'redefinition': {
         if (redefinition != null) {
           spec.warn({
@@ -538,6 +541,34 @@ export function parseStructuredHeaderDl(
         }
         break;
       }
+      case 'skip return checks': {
+        if (skipReturnChecks != null) {
+          spec.warn({
+            type: 'node',
+            ruleId: 'header-format',
+            message: `duplicate "skip return checks" attribute`,
+            node: dt,
+          });
+        }
+        const contents = (dd.textContent ?? '').trim();
+        if (contents === 'true') {
+          skipReturnChecks = true;
+        } else if (contents === 'false') {
+          skipReturnChecks = false;
+        } else {
+          spec.warn({
+            type: 'contents',
+            ruleId: 'header-format',
+            message: `unknown value for "skip return checks" attribute (expected "true" or "false", got ${JSON.stringify(
+              contents,
+            )})`,
+            node: dd,
+            nodeRelativeLine: 1,
+            nodeRelativeColumn: 1,
+          });
+        }
+        break;
+      }
       case '': {
         spec.warn({
           type: 'node',
@@ -564,6 +595,7 @@ export function parseStructuredHeaderDl(
     effects,
     redefinition: redefinition ?? false,
     skipGlobalChecks: skipGlobalChecks ?? false,
+    skipReturnChecks: skipReturnChecks ?? false,
   };
 }
 

src/typechecker.ts

@@ -275,7 +275,10 @@ export function typecheck(spec: Spec) {
       )
         ? null
         : false;
-    const returnType = signature?.return == null ? null : typeFromExprType(signature.return);
+    const returnType =
+      biblioEntry?._skipReturnChecks || signature?.return == null
+        ? null
+        : typeFromExprType(signature.return);
     let numberOfAbstractClosuresWeAreWithin = 0;
     const walkLines = (list: OrderedListNode) => {
       for (const line of list.contents) {

test/typecheck.js

@@ -598,6 +598,39 @@ describe('typechecking completions', () => {
         </emu-alg>
         </emu-clause>
       `);
+
+      await assertLintFree(`
+        <emu-clause id="sec-completion-ao" type="abstract operation">
+          <h1>
+            Completion (
+              _completionRecord_: a Completion Record,
+            ): a Completion Record
+          </h1>
+          <dl class="header">
+            <dt>skip return checks</dt>
+            <dd>true</dd>
+          </dl>
+          <emu-alg>
+            1. Assert: _completionRecord_ is a Completion Record.
+            1. Return _completionRecord_.
+          </emu-alg>
+        </emu-clause>
+
+        <emu-clause id="sec-normalcompletion" type="abstract operation">
+          <h1>
+            NormalCompletion (
+              _value_: any value except a Completion Record,
+            ): a normal completion
+          </h1>
+          <dl class="header">
+            <dt>skip return checks</dt>
+            <dd>true</dd>
+          </dl>
+          <emu-alg>
+            1. Return Completion Record { [[Type]]: ~normal~, [[Value]]: _value_, [[Target]]: ~empty~ }.
+          </emu-alg>
+        </emu-clause>
+      `);
     });
   });