JSSpecCompiler: Parse "Perform <expression>." steps

Author: https://github.com/DanShaders
Commit: ddf26a768c
Pull-request: https://github.com/SerenityOS/serenity/pull/23123
Reviewed-by: https://github.com/ADKaster ✅

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

@@ -463,6 +463,18 @@ TextParseErrorOr<Tree> TextParser::parse_assignment()
     return make_ref_counted<BinaryOperation>(op, lvalue, rvalue);
 }
 
+// perform <expr>
+TextParseErrorOr<Tree> TextParser::parse_perform()
+{
+    auto rollback = rollback_point();
+
+    TRY(consume_word("perform"sv));
+    auto value = TRY(parse_expression());
+
+    rollback.disarm();
+    return value;
+}
+
 // <simple_step>
 TextParseErrorOr<Tree> TextParser::parse_simple_step_or_inline_if_branch()
 {
@@ -493,6 +505,14 @@ TextParseErrorOr<Tree> TextParser::parse_simple_step_or_inline_if_branch()
         return result.release_value();
     }
 
+    // Perform <expr>.$
+    if (auto result = parse_perform(); !result.is_error()) {
+        TRY(consume_token_with_type(TokenType::Dot));
+        TRY(expect_eof());
+        rollback.disarm();
+        return result.release_value();
+    }
+
     return TextParseError {};
 }
 

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

@@ -84,6 +84,7 @@ private:
     TextParseErrorOr<Tree> parse_return_statement();
     TextParseErrorOr<Tree> parse_assert();
     TextParseErrorOr<Tree> parse_assignment();
+    TextParseErrorOr<Tree> parse_perform();
     TextParseErrorOr<Tree> parse_simple_step_or_inline_if_branch();
     TextParseErrorOr<IfConditionParseResult> parse_if_beginning();
     TextParseErrorOr<Tree> parse_inline_if_else();