Daniel Hartwig <mand...@gmail.com> writes: > On 11 June 2012 20:20, David Kastrup <d...@gnu.org> wrote: >>> P.S.: I still need to look at vlists. They might already address this >>> issue, though I can't use them in Guile 1.8. >> >> No, the "immutable" angle would make them unsuitable again. > > Note that vlists are only immutable in the sense that you can not > modify the value of a slot already allocated.
Which makes it useless here. >> 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). > > From this I gather that your use case only appends to the lattice, if > so, vlist is suitable for that task. Wrong. My use case only _allocates_ at the end of the existing type lattice, but the records are not read-only. >> Cough, cough. Standard vectors are not growable. Which is the >> original problem of this thread, never mind Lua. > > True, but a growable vector is a tiny step away from the standard > vector. A tiny step if you are modifying the C code. A not so tiny step if you are working with Scheme. >> hashtables have additional indirection >> through hash buckets and coalescing lists > > This is fairly standard for a hash table. I would be quite surprised > if the hash table part of a Lua table did not also use buckets. But it is not standard for a growable vector that it only comes with buckets and chains. >> Except that this one isn't. > > Why not? > > You take a vector and a hash table, store your values in them, and > grow either as needed. This is not a complicated type. Except that vectors don't grow. Are you even reading what you are replying to? -- David Kastrup
