* breaking changes to the API. Some of the weird decisions from before
are changed to what would be more expected.
- `get` returns `?V`, use `getEntry` for the old API.
- `put` returns `!void`, use `fetchPut` for the old API.
* HashMap now has a comptime parameter of whether to store hashes with
entries. AutoHashMap has heuristics on whether to set this parameter.
For example, for integers, it is false, since equality checking is
cheap, but for strings, it is true, since equality checking is
probably expensive.
* The implementation has a separate array for entry_index /
distance_from_start_index. Entries no longer has holes; it is an
ArrayList, and iteration is simpler and more cache coherent.
This is inspired by Python's new dictionaries.
* HashMap is separated into an "unmanaged" and a "managed" API. The
unmanaged API is where the actual implementation is; the managed API
wraps it and provides a more convenient API, storing the allocator.
* Memory usage: When there are less than or equal to 8 entries, HashMap
now incurs only a single pointer-size integer as overhead, opposed to
using an ArrayList.
* Since the entries array is separate from the indexes array, the holes
in the indexes array take up less room than the holes in the entries
array otherwise would. However the entries array also allocates
additional capacity for appending into the array.
* HashMap now maintains insertion order. Deletion performs a "swap
remove". It's now possible to modify the HashMap while iterating.
This is a bit hacky since we end up doing more than just grabbing
the stack pointer in the inline assembly block. Ideally _start would
be implemented in pure asm for powerpc64le, but this will do for now.
Still to be implemented is powerpc, powerpc64, and powerpc64 (ELFv2)
support. The latter will just require correctly determing target ABI
for powerpc64 and enabling the existing powerpc64le implementation for
it.
This is direct result of review comments left by andrewrk and
daurnimator. It makes sense to map `ENOTCAPABLE` into a more generic
`error.AccessDenied`.
This commit adds `error.NotCapable` enum value and makes sure that
every applicable WASI syscall that can return `ENOTCAPABLE` errno
remaps it to `error.NotCapable.
Linux deviates from POSIX and returns EISDIR while other POSIX systems return EPERM. To make all platforms consistent in their errors when calling deleteFile on a directory, we have to do a stat to translate EPERM (AccessDenied) to EISDIR (IsDir).
Also, add more informative `@compileError` in a few `std.os` functions
that would otherwise yield a cryptic compile error when targeting
WASI. Finally, enhance docs in a few places and add test case for
`fstatat`.
