[kgr]

Correct, no single interface does what the UNIX pipe did for command-line text-based IO-stream processing programs. In FOAM, we have about 20 standard interfaces, which correspond to your different glue types. Things like DAO (Data Access Object), Model, View, Factory, Parser, Adapter, Authenticator, Outputter, Validator, ... and as long as everything that does a certain thing, implements the corresponding interface, then everything can be piped together. Again, see: https://www.youtube.com/watch?v=S4LbUv5FsGQ or the longer more complete version: https://www.youtube.com/watch?v=PsFLlgrzn2E

To continue your analogy, if 95% of your house were made of glue, and 85% of the cost of your house was to buy glue, then that would be some cause for concern. That is pretty close to the truth for software.