When `std.mem.indexOf` is called with a single-item needle, use `indexOfScalarPos` which is significantly faster than the more general `indexOfPosLinear`. This can be done without introducing overhead to normal cases (where `needle.len > 1`).
These are an order of magnitude quicker than the previous
implementations:
A relative comparison of each, measuring scanning a 1G file.
Reading 1G (1.0000000009313226GiB)
std.mem.sliceTo: 281.232ms
vectorized.sliceTo: 24.769ms
strlen: 24.291ms
std.indexOfScalar: 229.016ms
vectorized.indexOfScalar: 24.685ms
memchr: 24.958ms
Most of this migration was performed automatically with `zig fmt`. There
were a few exceptions which I had to manually fix:
* `@alignCast` and `@addrSpaceCast` cannot be automatically rewritten
* `@truncate`'s fixup is incorrect for vectors
* Test cases are not formatted, and their error locations change
Anecdote 1: The generic version is way more popular than the non-generic
one in Zig codebase:
git grep -w alignForward | wc -l
56
git grep -w alignForwardGeneric | wc -l
149
git grep -w alignBackward | wc -l
6
git grep -w alignBackwardGeneric | wc -l
15
Anecdote 2: In my project (turbonss) that does much arithmetic and
alignment I exclusively use the Generic functions.
Anecdote 3: we used only the Generic versions in the Macho Man's linker
workshop.
Failing to forward free calls to the underlying allocator makes
`ValidationAllocator` unusable for testing allocators while checking for
leaks. This change allows allocators that wrap `std.testing.allocator`
to be tested with `std.heap.testAllocator()` in test decls without
reporting erroneous leaks.
This allows users to choose which version they need for their particular use case, as the previous default (now the 'any' version) was (1) not always the desired type of delimiter and (2) performed worse than the scalar version if the delimiter was a single item.
This allows users to choose which version they need for their particular use case, as the previous default (now the 'full' version) was (1) not always the desired type of delimiter and (2) performed worse than the scalar version if the delimiter was a single item.
This introduces a parallel set of functions to the std.mem.indexOfAny
functions. They simply invert the logic, yielding the first/last index
which is *not* contained in the "values" slice.
Inverting this logic is useful when you are attempting to determine the
initial span which contains only characters in a particular set.
* Document the `indexOfNone` family.
These descriptions are somewhat brief, but the functions themselves are
also simple enough to describe in such a way.
The majority of these are in comments, some in doc comments which might
affect the generated documentation, and a few in parameter names -
nothing that should be breaking, however.
* docs(std.math): elaborate on difference between absCast and absInt
* docs(std.rand.Random.weightedIndex): elaborate on likelihood
I think this makes it easier to understand.
* langref: add small reminder
* docs(std.fs.path.extension): brevity
* docs(std.bit_set.StaticBitSet): mention the specific types
* std.debug.TTY: explain what purpose this struct serves
This should also make it clearer that this struct is not supposed to provide unrelated terminal manipulation functionality such as setting the cursor position or something because terminals are complicated and we should keep this struct simple and focused on debugging.
* langref(package listing): brevity
* langref: explain what exactly `threadlocal` causes to happen
* std.array_list: link between swapRemove and orderedRemove
Maybe this can serve as a TLDR and make it easier to decide.
* PrefetchOptions.locality: clarify docs that this is a range
This confused me previously and I thought I can only use either 0 or 3.
* fix typos and more
* std.builtin.CallingConvention: document some CCs
* langref: explain possibly cryptic names
I think it helps knowing what exactly these acronyms (@clz and @ctz) and
abbreviations (@popCount) mean.
* variadic function error: add missing preposition
* std.fmt.format docs: nicely hyphenate
* help menu: say what to optimize for
I think this is slightly more specific than just calling it
"optimizations". These are speed optimizations. I used the word
"performance" here.
ccf670c made using `return` from within a comptime block in a non-inline
function illegal, since it is a use of runtime control flow in a
comptime block. It is allowed if the function in question is `inline`,
since no actual control flow occurs in this case. A few functions from
std (notably `std.fmt.comptimePrint`) needed to be marked `inline` to
support this change.
