[v8-juice] r2234 committed - Edited wiki page V8Convert_FunctionBinding through web user interface.
v8-j...@googlecode.com
Author: sgb...@gmail.com
Date: Mon Apr 9 00:44:21 2012
Log: Edited wiki page V8Convert_FunctionBinding through web user
interface.
http://code.google.com/p/v8-juice/source/detail?r=2234
Modified:
/wiki/V8Convert_FunctionBinding.wiki
=======================================
--- /wiki/V8Convert_FunctionBinding.wiki Thu Aug 18 07:47:49 2011
+++ /wiki/V8Convert_FunctionBinding.wiki Mon Apr 9 00:44:21 2012
@@ -1,9 +1,9 @@
#summary V8Convert's native function-binding API
-#labels Topic-CPlusPlus,Phase-UserDocs
+#labels Topic-CPlusPlus,Phase-UserDocs,Topic-cvv8
<wiki:toc/>
-See also: [V8Convert_Overloading], [V8Convert_PropertyBinding],
[V8Convert_XTo]
+See also: [V8Convert], [V8Convert_Overloading],
[V8Convert_PropertyBinding], [V8Convert_XTo]
= Introduction to Function Binding =
@@ -156,10 +156,10 @@
== The (`char [const] *`) Problem ==
-Because of issues regarding the ownership and lifetimes of raw C-style
string, functions taking `(char const *)` have a few relatively minor
limitations:
+Because of issues regarding the ownership and lifetimes of raw C-style
string, functions taking `(char [const] *)` have a few relatively minor
limitations:
* The C-strings _must_ be `NULL` or nul-terminated. It cannot be used
with binary data because they are converted to JS strings.
- * Non-const (`char *`) is not supported. We could partially implement it
using a proxy, but the changes would get lost on their way back to JS space
because the JS calling conventions do not allow us to pass changes to
strings back this way.
+ * Non-const (`char *`) ~~is not supported~~ support was added 20120408,
with the caveat that changes made to the string contents by the called
function cannot be passed back to JS space because the JS calling
conventions do not allow us to pass changes to strings back this way.
* The bound function _must not_ hold the pointer it is passed after it
returns. It must either consume or ignore the input, and keep no copy of
the pointer itself. It is also illegal (it was determined only after a
debugging session) to _return_ the pointer passed to the function, as that
indirectly extends its lifetime past its legal point. That particular case
actually works on some platforms but that only exemplifies the evil nature
of Undefined Behaviour.
* The internal conversion process uses `v8::String::Utf8Value`,
and "should" be safe for use with functions accepting ASCII or UTF8 input.
Behaviour with any other encodings is undefined.
* If passed a JS `null` or `undefined`, it converts to a literal `NULL`,
otherwise it will convert to a string (though possibly empty). This is
significant for functions which treat `NULL` different than an empty string
(like `strlen()`, which may crash your app if passed `NULL`).