Tirade is a "small subset of the Smalltalk language" that is intended for file formats. Tirade does "streaming parsing" (like SAX) of an input stream which consists of a sequence of Smalltalk messages with literals as arguments - expressions are not allowed. A typical use is sending these messages one by one to a builder object, supplied by the user. Tirade is almost a strict subset of Smalltalk BUT there is no receiver to the left. The receiver is typically the builder according to the above logic.
This more or less matches the capability of JSON and more.