From: C.Reinke [mailto:C.Reinke@ukc.ac.uk]
Am I the only one who finds the exclusive emphasis on combinator languages slightly disappointing [...]? [...]
The paper somewhat downplays the role of embedding the combinator-based DSL in a full functional language while also mentioning that some features gained for free in the Haskell prototype considerably complicate implementations in other languages. I would be interested to hear more about these aspects: [...]
Another important consideration is whether the combinator library is higher-order. If so, it will be awkward to use from a language without a lightweight notation for (first-class) functions. This lack was a huge drawback in DirectAnimation, the now-defunct product cousin of Fran, which eviscerated the crucially higher-order event algebra. Similarly, when a combinator lib uses parametric polymorphism, it is painful to use from a language without. (Same example.) It seems that these features just weren't important in the case of "Composing Contracts". - Conal