Code Generation
When the time came to run the acceptance tests, we brought the client in, showed them this language, and explained how it was used to produce the document. We then showed them some new magic: we fed the same document through a different code generator and it produced a whole lot of C code, one function per test. They verified that this C did indeed represent the contents of the document, then we compiled and ran it. The entire Telex switch acceptance tests were run from this domain language (and, amazingly, it passed).
