Function ExtractFrontmatterFromBuiltinFile

pkg/parser/frontmatter_content.go:229–242

ExtractFrontmatterFromBuiltinFile is a caching wrapper around ExtractFrontmatterFromContent for builtin virtual files. Because builtin files are registered once at startup and never change, the parsed FrontmatterResult is identical across calls. This function caches the first parse result in builtin

(path string, content []byte)

//
// path must start with BuiltinPathPrefix ("@builtin:"); an error is returned otherwise.
func ExtractFrontmatterFromBuiltinFile(path string, content []byte) (*FrontmatterResult, error) {
	if !strings.HasPrefix(path, BuiltinPathPrefix) {
		return nil, fmt.Errorf("ExtractFrontmatterFromBuiltinFile: path %q does not start with %q", path, BuiltinPathPrefix)
	}
	if cached, ok := GetBuiltinFrontmatterCache(path); ok {
		return cached, nil
	}
	result, err := ExtractFrontmatterFromContent(string(content))
	if err != nil {
		return nil, err
	}
	// SetBuiltinFrontmatterCache uses LoadOrStore so concurrent races are safe.
	return SetBuiltinFrontmatterCache(path, result), nil
}

// ExtractMarkdownSection extracts a specific section from markdown content
// Supports H1-H3 headers and proper nesting (matches bash implementation)