JSSpecCompiler: Ignore notes in algorithm steps

Meta/Lagom/Tools/CodeGenerators/JSSpecCompiler/Parser/SpecParser.cpp

@@ -97,7 +97,7 @@ bool AlgorithmStep::parse()
 {
     TextParser parser(m_ctx, m_tokens, m_node);
 
-    TextParseErrorOr<Tree> parse_result = TextParseError {};
+    TextParseErrorOr<NullableTree> parse_result = TextParseError {};
     if (m_substeps)
         parse_result = parser.parse_step_with_substeps(RefPtr(m_substeps).release_nonnull());
     else
@@ -133,10 +133,12 @@ Optional<AlgorithmStepList> AlgorithmStepList::create(SpecificationParsingContex
                         update_logical_scope_for_step(ctx, parent_scope, step_number);
                         return AlgorithmStep::create(ctx, child);
                     });
-                    if (!step_creation_result.has_value())
+                    if (!step_creation_result.has_value()) {
                         all_steps_parsed = false;
-                    else
-                        step_expressions.append(step_creation_result.release_value().tree());
+                    } else {
+                        if (auto expression = step_creation_result.release_value().tree())
+                            step_expressions.append(expression.release_nonnull());
+                    }
                     ++step_number;
                     return;
                 }

Meta/Lagom/Tools/CodeGenerators/JSSpecCompiler/Parser/SpecParser.h

@@ -62,7 +62,7 @@ class AlgorithmStep {
 public:
     static Optional<AlgorithmStep> create(SpecificationParsingContext& ctx, XML::Node const* node);
 
-    Tree tree() const { return m_expression; }
+    NullableTree tree() const { return m_expression; }
 
 private:
     AlgorithmStep(SpecificationParsingContext& ctx)
@@ -75,7 +75,7 @@ private:
     SpecificationParsingContext& m_ctx;
     Vector<Token> m_tokens;
     XML::Node const* m_node;
-    Tree m_expression = error_tree;
+    NullableTree m_expression = error_tree;
     NullableTree m_substeps;
 };
 

Meta/Lagom/Tools/CodeGenerators/JSSpecCompiler/Parser/TextParser.cpp

@@ -598,10 +598,16 @@ TextParseErrorOr<Tree> TextParser::parse_else(Tree else_branch)
 }
 
 // <simple_step> | <inline_if>
-TextParseErrorOr<Tree> TextParser::parse_step_without_substeps()
+TextParseErrorOr<NullableTree> TextParser::parse_step_without_substeps()
 {
     auto rollback = rollback_point();
 
+    // NOTE: ...
+    if (auto result = consume_word("NOTE:"sv); !result.is_error()) {
+        rollback.disarm();
+        return nullptr;
+    }
+
     // <simple_step>
     if (auto result = parse_simple_step_or_inline_if_branch(); !result.is_error()) {
         rollback.disarm();

Meta/Lagom/Tools/CodeGenerators/JSSpecCompiler/Parser/TextParser.h

@@ -56,7 +56,7 @@ public:
     }
 
     TextParseErrorOr<ClauseHeader> parse_clause_header(ClauseHasAoidAttribute clause_has_aoid_attribute);
-    TextParseErrorOr<Tree> parse_step_without_substeps();
+    TextParseErrorOr<NullableTree> parse_step_without_substeps();
     TextParseErrorOr<Tree> parse_step_with_substeps(Tree substeps);
 
     FailedTextParseDiagnostic get_diagnostic() const;

Meta/Lagom/Tools/CodeGenerators/JSSpecCompiler/Tests/spec-parsing.xml

@@ -73,4 +73,13 @@
          </ol>
       </emu-alg>
    </emu-clause>
+   <emu-clause id="7" aoid="Notes">
+      <h1><span class="secnum">7</span> Notes ( )</h1>
+      <emu-alg>
+         <ol>
+            <li>NOTE: This abstract operation returns <emu-const>unused</emu-const> in case you didn't notice.</li>
+            <li>Return <emu-const>unused</emu-const>.</li>
+         </ol>
+      </emu-alg>
+   </emu-clause>
 </specification>

Meta/Lagom/Tools/CodeGenerators/JSSpecCompiler/Tests/spec-parsing.xml.expectation

@@ -100,3 +100,8 @@ TreeList
   ReturnNode
     WellKnownNode Undefined
 
+Notes():
+TreeList
+  ReturnNode
+    Enumerator unused
+