- ast.rs: Param, FieldDef, FuncDef, StructDef, TopLevelDef, TopLevelDefKind, Program - parser.rs: parse_program, parse_top_level_def, parse_func_def, parse_struct_def with param/field list helpers; synchronize_top_level for recovery; 14 new tests (76 total) - main.rs: parse source file as a Program and print the AST