parse a string into a typenode ast node , applying substitutions . concode_field_sep ExtensionInfo ext concode_elem_sep int EXPR concode_elem_sep int DECL concode_elem_sep Position pos concode_elem_sep int MEMB concode_elem_sep int STMT concode_elem_sep int TYPE concode_elem_sep int FILE concode_field_sep ClassMember parseMember concode_elem_sep ClassMember parseMember concode_elem_sep QQParser parser concode_elem_sep Stmt parseStmt concode_elem_sep Stmt parseStmt concode_elem_sep ClassDecl parseDecl concode_elem_sep ClassDecl parseDecl concode_elem_sep SourceFile parseFile concode_elem_sep SourceFile parseFile concode_elem_sep Position type_position concode_elem_sep Node parse concode_elem_sep Lexer lexer concode_elem_sep Expr parseExpr concode_elem_sep Expr parseExpr