> Scheme/Guile vectors are fixed size. Now I have a situation where I
> have a basic type lattice with records stored in vectors, and this type
> lattice may be extended dynamically (which typically happens at the
> start of a whole file, for potentially multi-file runs). Scheme does
> not offer a suitable data structure for that.
If only grows at one end, something like C++ std::deque might be suitable. It has the advantage of not having to invoke copy constructors when it grows.