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Merge branch 'master' into v2.1

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This commit is contained in:
Mike Pall
2022-06-23 09:10:43 +02:00
parent 0065cff7e0 2e98c3d064
commit 4c2441c16c
13 changed files with 82 additions and 82 deletions
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24
doc/ext_ffi_tutorial.html
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@@ -85,7 +85,7 @@ of its functions:
local ffi = require("ffi")
</pre>
<p>
Please note this doesn't define an <tt>ffi</tt> variable in the table
Please note, this doesn't define an <tt>ffi</tt> variable in the table
of globals &mdash; you really need to use the local variable. The
<tt>require</tt> function ensures the library is only loaded once.
</p>
@@ -194,7 +194,7 @@ don't need to declare them as such.
<span class="mark">&#9316;</span> The <tt>poll()</tt>
function takes a couple more arguments we're not going to use. You can
simply use <tt>nil</tt> to pass a <tt>NULL</tt> pointer and <tt>0</tt>
for the <tt>nfds</tt> parameter. Please note that the
for the <tt>nfds</tt> parameter. Please note, that the
number&nbsp;<tt>0</tt> <em>does not convert to a pointer value</em>,
unlike in C++. You really have to pass pointers to pointer arguments
and numbers to number arguments.
@@ -291,12 +291,12 @@ Here's the step-by-step explanation:
<p>
<span class="mark">&#9312;</span> This defines some of the
C&nbsp;functions provided by zlib. For the sake of this example, some
type indirections have been reduced and it uses the pre-defined
type indirections have been reduced and it uses the predefined
fixed-size integer types, while still adhering to the zlib API/ABI.
</p>
<p>
<span class="mark">&#9313;</span> This loads the zlib shared
library. On POSIX systems it's named <tt>libz.so</tt> and usually
library. On POSIX systems, it's named <tt>libz.so</tt> and usually
comes pre-installed. Since <tt>ffi.load()</tt> automatically adds any
missing standard prefixes/suffixes, we can simply load the
<tt>"z"</tt> library. On Windows it's named <tt>zlib1.dll</tt> and
@@ -324,7 +324,7 @@ actual length that was used.
<p>
In C you'd pass in the address of a local variable
(<tt>&amp;buflen</tt>). But since there's no address-of operator in
Lua, we'll just pass in a one-element array. Conveniently it can be
Lua, we'll just pass in a one-element array. Conveniently, it can be
initialized with the maximum buffer size in one step. Calling the
actual <tt>zlib.compress2</tt> function is then straightforward.
</p>
@@ -348,7 +348,7 @@ for garbage collection and string interning.
<span class="mark">&#9317;</span> The <tt>uncompress</tt>
functions does the exact opposite of the <tt>compress</tt> function.
The compressed data doesn't include the size of the original string,
so this needs to be passed in. Otherwise no surprises here.
so this needs to be passed in. Otherwise, no surprises here.
</p>
<p>
<span class="mark">&#9318;</span> The code, that makes use
@@ -382,7 +382,7 @@ Ok, so the <tt>ffi.*</tt> functions generally accept cdata objects
wherever you'd want to use a number. That's why we get a away with
passing <tt>n</tt> to <tt>ffi.string()</tt> above. But other Lua
library functions or modules don't know how to deal with this. So for
maximum portability one needs to use <tt>tonumber()</tt> on returned
maximum portability, one needs to use <tt>tonumber()</tt> on returned
<tt>long</tt> results before passing them on. Otherwise the
application might work on some systems, but would fail in a POSIX/x64
environment.
@@ -454,7 +454,7 @@ the origin.
</p>
<p>
<span class="mark">&#9315;</span> If we run out of operators, we can
define named methods, too. Here the <tt>__index</tt> table defines an
define named methods, too. Here, the <tt>__index</tt> table defines an
<tt>area</tt> function. For custom indexing needs, one might want to
define <tt>__index</tt> and <tt>__newindex</tt> <em>functions</em> instead.
</p>
@@ -468,13 +468,13 @@ be used e.g. to create an array of points. The metamethods automatically
apply to any and all uses of this type.
</p>
<p>
Please note that the association with a metatable is permanent and
Please note, that the association with a metatable is permanent and
<b>the metatable must not be modified afterwards!</b> Ditto for the
<tt>__index</tt> table.
</p>
<p>
<span class="mark">&#9317;</span> Here are some simple usage examples
for the point type and their expected results. The pre-defined
for the point type and their expected results. The predefined
operations (such as <tt>a.x</tt>) can be freely mixed with the newly
defined metamethods. Note that <tt>area</tt> is a method and must be
called with the Lua syntax for methods: <tt>a:area()</tt>, not
@@ -483,7 +483,7 @@ called with the Lua syntax for methods: <tt>a:area()</tt>, not
<p>
The C&nbsp;type metamethod mechanism is most useful when used in
conjunction with C&nbsp;libraries that are written in an object-oriented
style. Creators return a pointer to a new instance and methods take an
style. Creators return a pointer to a new instance, and methods take an
instance pointer as the first argument. Sometimes you can just point
<tt>__index</tt> to the library namespace and <tt>__gc</tt> to the
destructor and you're done. But often enough you'll want to add
@@ -569,7 +569,7 @@ end
</pre>
<p>
This turns them into indirect calls and generates bigger and slower
machine code. Instead you'll want to cache the namespace itself and
machine code. Instead, you'll want to cache the namespace itself and
rely on the JIT compiler to eliminate the lookups:
</p>
<pre class="code">