[ANN] stdlib 39 released
[
Date Prev][
Date Next][
Thread Prev][
Thread Next]
[
Date Index]
[
Thread Index]
- Subject: [ANN] stdlib 39 released
- From: Gary Vaughan <gary@...>
- Date: 2014年4月23日 19:15:57 +0700
General Lua Libraries
I am happy to announce release 39 of stdlib.
stdlib's home page has moved to http://lua-stdlib.github.io/lua-stdlib
This release finally reaches the point where using any of the `std.`-
prefixed modules merely returns a table of module functions, without
changing any core metatables or changing any other namespaces. For
backwards compatibility, `require "std"` continues to scribble over
all of those things as it always has, but that too will be fixed in
the next release, so you might want to start updating any client code
you plan to keep in sync with modern stdlib.
The effort to make all modules for which it makes sense provide
`std.object` derived prototypes is also complete now.
This release also fixes all known issues, so if you find anything
broken, please submit a report to:
http://lua-stdlib.github.io/lua-stdlib/issues
There's also the usual selection of small improvements outlined below.
* Noteworthy changes in release 39 (2014年04月23日) [stable]
** New features:
- New `std.functional.case` function for rudimentary case statements.
The main difference from serial if/elseif/end comparisons is that
`with` is evaluated only once, and then the match function is looked
up with an O(1) table reference and function call, as opposed to
hoisting an expression result into a temporary variable, and O(n)
comparisons.
The function call overhead is much more significant than several
comparisons, and so `case` is slower for all but the largest series
of if/elseif/end comparisons. It can make your code more readable,
however.
See LDocs for usage.
- New pathstring management functions in `std.package`.
Manage `package.path` with normalization, duplicate removal,
insertion & removal of elements and automatic folding of '/' and '?'
onto `package.dirsep` and `package.path_mark`, for easy addition of
new paths. For example, instead of all this:
lib = std.io.catfile (".", "lib", package.path_mark .. ".lua")
paths = std.string.split (package.path, package.pathsep)
for i, path in ipairs (paths) do
... lots of normalization code...
end
i = 1
while i <= #paths do
if paths[i] == lib then
table.remove (paths, i)
else
i = i + 1
end
end
table.insert (paths, 1, lib)
package.path = table.concat (paths, package.pathsep)
You can now write just:
package.path = package.normalize ("./lib/?.lua", package.path)
- `std.optparse:parse` accepts a second optional parameter, a table of
default option values.
- `table.clone` accepts an optional table of key field renames in the
form of `{oldkey = newkey, ...}` subsuming the functionality of
`table.clone_rename`. The final `nometa` parameter is supported
whether or not a rename map is given:
r = table.clone (t, "nometa")
r = table.clone (t, {oldkey = newkey}, "nometa")
** Deprecations:
- `table.clone_rename` now gives a warning on first call, and will be
removed entirely in a few releases. The functionality has been
subsumed by the improvements to `table.clone` described above.
** Bug fixes:
- `std.optparse` no longer throws an error when it encounters an
unhandled option in a combined (i.e. `-xyz`) short option string.
- Surplus unmapped fields are now discarded during object cloning, for
example when a prototype has `_init` set to `{ "first", "second" }`,
and is cloned using `Proto {'one', 'two', 'three'}`, then the
unmapped `three` argument is now discarded.
- The path element returned by `std.tree.nodes` can now always be
used as a key list to dereference the root of the tree, particularly
`tree[{}]` now returns the root node of `tree`, to match the initial
`branch` and final `join` results from a full traversal by
`std.tree.nodes (tree)`.
** Incompatible changes:
- `std.string` no longer sets `__append`, `__concat` and `__index` in
the core strings metatable by default, though `require "std"` does
continue to do so. See LDocs for `std.string` for details.
- `std.optparse` no longer normalizes unhandled options. For example,
`--unhandled-option=argument` is returned unmolested from `parse`,
rather than as two elements split on the `=`; and if a combined
short option string contains an unhandled option, then whatever was
typed at the command line is returned unmolested, rather than first
stripping off and processing handled options, and returning only the
unhandled substring.
- Setting `_init` to `{}` in a prototype object will now discard all
positional parameters passed during cloning, because a table valued
`_init` is a list of field names, beyond which surplus arguments (in
this case, all arguments!) are discarded.
Install it with LuaRocks, using:
luarocks install stdlib 39
Until the rocks are available from the official repository in a few days,
you can install directly from the stdlib release branch, with:
$ luarocks install \
https://raw.githubusercontent.com/lua-stdlib/lua-stdlib/release-v39/stdlib-39-1.rockspec