[PATCH] Namespace Patch, Beta 1

21 years ago by Jessie Hernandez — view source — reply

unread

Attached is the latest version of the namespace patch! It finally includes
namespace imports and it even includes anonymous namespace support. Also,
the previous bison shift/reduce conflict has been removed. Here is a
summary of its features:

Simple imports: import ns:class1;
Import aliases: import ns:class1 as my_alias;
Namespace imports: import namespace ns;
Anonymous namespaces: namespace { class file_class{} }
Namespace-private classes: namespace ns{ private class prv_class{} }

Two new functions have also been added to support namespace imports (more on
that below):

get_imported_namespaces([$className])
Returns an array of imported namespaces for the current file. If a class
name is passed, and this class is currently being autoloaded (also meaning
that this function is called inside __autoload), then the list of returned
imported namespaces is based on the file that triggered the __autoload
call.
autoload_import_class($className, $namespaceName)
Imports a class in a given namespace for the currently executing file (can
ONLY be used inside __autoload!)

Imports

Imports and namespace imports are handled completely by the user with the
use of the __autloload function. This means that there are no restrictions
on class file naming/directory structure. For simple imports, the class
name will be passed with its full name (including the colons, such as
"ns:class1"). For namespace imports, only the class name will be called.
Since the user needs to determine which namespace (or namespaces) a class
belongs to, the "get_imported_namespaces" function is provided to check the
imported namespaces for the currently-executing file. Once the user is
satisfied with a match, he/she needs to perform an "import" for this class,
but this needs to be done on the executing file, not the file where
__autoload is defined. For this reason, the autoload_import_class function
is provided. A sample usage of both these functions is at
tests/classes/namespace_autoload.php.

Namespace-private classes

Classes marked as "private" from within a namespace can only be used by
classes defined in the same namespace.

Anonymous namespaces

Classes defined inside anonymous namespaces can only be used within the file
that declared the anonymous namespace.

I believe the attached patch solves the issues that were presented long ago
for namespaces. Referring to the post by Daniel Cogwill at
http://www.zend.com/lists/engine2/200304/msg00164.html, the following are
my answers to the problems he found at the time:

import-all silently hides local names.
A: If a global class is defined with the same name as a class in a
namespace, and the namespace class has been imported in the same script,
the global class takes precedence. The namespace class can still be used by
using its full name, i.e. namespace_name:class_name.
Interestingly (and I assume this is simply a bug), functions and classes
behave differently wrt to import-all and duplicate definitions.
A: Irrelevant in this patch.
There is no way to hide names from import (i.e. make a name
non-exportable). This is a fundamental namespace feature, and there is
already an appropriate keyword (private).
A: Namespace-private classes are supported, using the "private" keyword.
The semantic meaning of successive imports depends on their relative
ordering.
A: The engine does not attempt to determine which class is included, the
user decides the most appropriate behavior inside __autoload.
The most egregious issue is that an import in an included file affects
the scope of the including file.
A: Imports in this patch only affect the file they are in.

Since I could not find a way to add the tests/classes/namespace directory
and subdirectories, I zipped them separately, as before.

Let me know if you have any questions on the attached patch.

Best regards,

Jessie Hernandez

21 years ago by dz@bitxtender.com — view source — reply

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This sounds awesome. Good job, Jessie. Keep it up!

David

-----Original Message-----
From: Jessie Hernandez [mailto:jrhernandez05@gmail.com]
Sent: Tuesday, August 02, 2005 6:07 AM
To: internals@lists.php.net
Subject: [PHP-DEV] [PATCH] Namespace Patch, Beta 1

Attached is the latest version of the namespace patch! It finally includes
namespace imports and it even includes anonymous namespace support. Also,
the previous bison shift/reduce conflict has been removed. Here is a
summary of its features:

Simple imports: import ns:class1;

Import aliases: import ns:class1 as my_alias;

Namespace imports: import namespace ns;

Anonymous namespaces: namespace { class file_class{} }

Namespace-private classes: namespace ns{ private class prv_class{} }

Two new functions have also been added to support namespace imports (more
on
that below):

get_imported_namespaces([$className])
Returns an array of imported namespaces for the current file. If a class
name is passed, and this class is currently being autoloaded (also meaning
that this function is called inside __autoload), then the list of returned
imported namespaces is based on the file that triggered the __autoload
call.

autoload_import_class($className, $namespaceName)
Imports a class in a given namespace for the currently executing file (can
ONLY be used inside __autoload!)

Imports

Imports and namespace imports are handled completely by the user with the
use of the __autloload function. This means that there are no restrictions
on class file naming/directory structure. For simple imports, the class
name will be passed with its full name (including the colons, such as
"ns:class1"). For namespace imports, only the class name will be called.
Since the user needs to determine which namespace (or namespaces) a class
belongs to, the "get_imported_namespaces" function is provided to check
the
imported namespaces for the currently-executing file. Once the user is
satisfied with a match, he/she needs to perform an "import" for this
class,
but this needs to be done on the executing file, not the file where
__autoload is defined. For this reason, the autoload_import_class function
is provided. A sample usage of both these functions is at
tests/classes/namespace_autoload.php.

Namespace-private classes

Classes marked as "private" from within a namespace can only be used by
classes defined in the same namespace.

Anonymous namespaces

Classes defined inside anonymous namespaces can only be used within the
file
that declared the anonymous namespace.

I believe the attached patch solves the issues that were presented long
ago
for namespaces. Referring to the post by Daniel Cogwill at
http://www.zend.com/lists/engine2/200304/msg00164.html, the following are
my answers to the problems he found at the time:

import-all silently hides local names.
A: If a global class is defined with the same name as a class in a
namespace, and the namespace class has been imported in the same script,
the global class takes precedence. The namespace class can still be used
by
using its full name, i.e. namespace_name:class_name.

Interestingly (and I assume this is simply a bug), functions and
classes
behave differently wrt to import-all and duplicate definitions.
A: Irrelevant in this patch.

There is no way to hide names from import (i.e. make a name
non-exportable). This is a fundamental namespace feature, and there is
already an appropriate keyword (private).
A: Namespace-private classes are supported, using the "private" keyword.

The semantic meaning of successive imports depends on their relative
ordering.
A: The engine does not attempt to determine which class is included, the
user decides the most appropriate behavior inside __autoload.

The most egregious issue is that an import in an included file affects
the scope of the including file.
A: Imports in this patch only affect the file they are in.

Since I could not find a way to add the tests/classes/namespace directory
and subdirectories, I zipped them separately, as before.

Let me know if you have any questions on the attached patch.

Best regards,

Jessie Hernandez

21 years ago by John LeSueur — view source — reply

unread

Jessie Hernandez wrote:

Attached is the latest version of the namespace patch! It finally includes
namespace imports and it even includes anonymous namespace support. Also,
the previous bison shift/reduce conflict has been removed. Here is a
summary of its features:

Simple imports: import ns:class1;

Import aliases: import ns:class1 as my_alias;

Namespace imports: import namespace ns;

Anonymous namespaces: namespace { class file_class{} }

Namespace-private classes: namespace ns{ private class prv_class{} }

Two new functions have also been added to support namespace imports (more on
that below):

get_imported_namespaces([$className])
Returns an array of imported namespaces for the current file. If a class
name is passed, and this class is currently being autoloaded (also meaning
that this function is called inside __autoload), then the list of returned
imported namespaces is based on the file that triggered the __autoload
call.

so, if I understand correctly, if your __autoload is defined in a
different file(file1) from where the import was
called(file2), then get_imported_namespaces() returns the namespace
imports for file1.
get_imported_namespaces($className) would return for file2, and outside
of the __autoload function,
get_imported_namespaces($className) would return the namespaces for
file1. That seems like
complicated semantics. Is there some way this could be simplified? Maybe
there should be two functions,
one that returns namespaces for file2 and is incorrect(throws an error)
to call from anywhere other than
__autoload(), and one that returns namespaces for file2.

autoload_import_class($className, $namespaceName)
Imports a class in a given namespace for the currently executing file (can
ONLY be used inside __autoload!)

Imports

Imports and namespace imports are handled completely by the user with the
use of the __autloload function. This means that there are no restrictions
on class file naming/directory structure. For simple imports, the class
name will be passed with its full name (including the colons, such as
"ns:class1"). For namespace imports, only the class name will be called.
Since the user needs to determine which namespace (or namespaces) a class
belongs to, the "get_imported_namespaces" function is provided to check the
imported namespaces for the currently-executing file. Once the user is
satisfied with a match, he/she needs to perform an "import" for this class,

This seems like it would be slow, as the user might have many
namespaces(directories) to search for matching
files. This would of course be up to the user. And it doesn't bother me
that a full namespace import
may not be as fast as a more specific import. In development it might be
convenient, but at some point, it's not
that big a deal to specify the classes you use.

but this needs to be done on the executing file, not the file where
__autoload is defined. For this reason, the autoload_import_class function
is provided. A sample usage of both these functions is at
tests/classes/namespace_autoload.php.

I like the option of having namespaces, and from the description this
seems to be a light method of doing it. It does
require some effort from the user. It seems that for most cases
__autoload will be the same every time, maybe with
different paths or file naming conventions.

John

21 years ago by Jessie Hernandez — view source — reply

unread

"John LeSueur" john@supernerd.com wrote in message
news:42EF3C7D.9000105@supernerd.com...

so, if I understand correctly, if your __autoload is defined in a
different file(file1) from where the import was
called(file2), then get_imported_namespaces() returns the namespace
imports for file1.
get_imported_namespaces($className) would return for file2, and outside
of the __autoload function,
get_imported_namespaces($className) would return the namespaces for
file1. That seems like
complicated semantics. Is there some way this could be simplified? Maybe
there should be two functions,
one that returns namespaces for file2 and is incorrect(throws an error)
to call from anywhere other than
__autoload(), and one that returns namespaces for file2.

To clarify the usage of this function (using your same example of file1 and
file2):

get_imported_namespaces() can be called in any file. It will return the
namespace imports for the currently-executing file (whether it's file1 or
file2).
When inside __autoload, get_imported_namespaces($className) will return
the namespace imports for the file that triggered the __autoload call (in
this case, file2).
When not inside __autoload, get_imported_namespaces($className) will
return an empty array.

I don't think the above usage is complicated. The only thing that can be
changed is the behavior of get_imported_namespaces($className) when not
inside __autoload. Right now it's returning an empty array. Will it be
better to return false and/or generate an error?

Imports

Imports and namespace imports are handled completely by the user with the
use of the __autloload function. This means that there are no
restrictions
on class file naming/directory structure. For simple imports, the class
name will be passed with its full name (including the colons, such as
"ns:class1"). For namespace imports, only the class name will be called.
Since the user needs to determine which namespace (or namespaces) a class
belongs to, the "get_imported_namespaces" function is provided to check
the
imported namespaces for the currently-executing file. Once the user is
satisfied with a match, he/she needs to perform an "import" for this
class,

This seems like it would be slow, as the user might have many
namespaces(directories) to search for matching
files. This would of course be up to the user. And it doesn't bother me
that a full namespace import
may not be as fast as a more specific import. In development it might be
convenient, but at some point, it's not
that big a deal to specify the classes you use.

This same search would have to be done by the engine, and although a bit
faster, this could also be slow depending on the number of imported
namespaces. Also, if the search is done by the engine, then a file
structure/naming convention would have to be enforced (that's why I had the
class_path .ini variable before), and some already mentioned that they have
different conventions, hence we need to provide flexibility to the user.

I agree with you that it's not a big deal to be explicit in specifying which
classes will be imported (in fact, when I have to write a Java class at
work, I always specify each class one-by-one, regardless of how many imports
I have to do, as it also makes the code clearer).

but this needs to be done on the executing file, not the file where
__autoload is defined. For this reason, the autoload_import_class
function
is provided. A sample usage of both these functions is at
tests/classes/namespace_autoload.php.

I like the option of having namespaces, and from the description this
seems to be a light method of doing it. It does
require some effort from the user. It seems that for most cases
__autoload will be the same every time, maybe with
different paths or file naming conventions.

You are correct, this is a very lightweight implementation. Very few (from
2-4 IIRC, depending on the type of import) hashtables are searched (this is
including class_table), and this number does not increase with the number of
class imports nor with the number of namespace imports.

Right now, it requires some initial effort from the user to implement the
imports, but as you said, this would only need to be done once (once the
__autoload function is defined, this can be included from all other
scripts).

--
Jessie

21 years ago by Jessie Hernandez — view source — reply

unread

Forgot to mention, since I expect the majority of users to follow the PEAR
convention for their classes (basically one class per file, file is named
like class, with "namespace" directories), then maybe a default
implementation can be provided in SPL's autoload. That way, namespace
imports can be used "out of the box".

Marcus, what do you think?

Regards,

Jessie Hernandez

21 years ago by Michael Wallner — view source — reply

unread

Hi Jessie Hernandez, you wrote:

Forgot to mention, since I expect the majority of users to follow the PEAR
convention for their classes (basically one class per file, file is named
like class, with "namespace" directories)

With the minor but essential logical difference:
$file = strtr($class, '_', '/')
I don't know if you took that into account though...

Regards,

Michael - < mike(@)php.net

21 years ago by Jessie Hernandez — view source — reply

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Hi Michael,

Yes, I am aware of this. Underscores were used due to the lack of
namespaces. For user classes which use namespaces (and in the case where
some PEAR classes get modified to be under namespaces), the colon would be
used as the separator, and this would get replaced by the slash to form the
file path.

--
Jessie

21 years ago by Marcus Boerger — view source — reply

unread

Hello Michael,

i suffest that pear finally takes a better approach with the arrival of
namespaces then the ugly workaround of '_'. If pear doesn#t want to i
suggest pear simply writes it's own __autoload().

marcus

Tuesday, August 2, 2005, 6:01:18 PM, you wrote:

Hi Jessie Hernandez, you wrote:

Forgot to mention, since I expect the majority of users to follow the PEAR
convention for their classes (basically one class per file, file is named
like class, with "namespace" directories)

With the minor but essential logical difference:
$file = strtr($class, '_', '/')
I don't know if you took that into account though...

Regards,

Michael - < mike(@)php.net >

Best regards,
Marcus

21 years ago by Michael Wallner — view source — reply

unread

Hi Marcus Boerger, you wrote:

Hello Michael,

i suffest that pear finally takes a better approach with the arrival of
namespaces then the ugly workaround of '_'.

Of course -- PEAR would benefit a lot of namespaces!

--
Michael - < mike(@)php.net

21 years ago by Marcus Boerger — view source — reply

unread

Hello Jessie,

what ever you want auto-of-the-box is good. I suggest the simplest
possible way as default which is we simply stay like we are doing now and
only include a replacement from ':' to the current directory separator.
That we would be searching for '.inc' and '.inc.php' per default in the
include_path directories.

marcus

Tuesday, August 2, 2005, 5:17:45 PM, you wrote:

Forgot to mention, since I expect the majority of users to follow the PEAR
convention for their classes (basically one class per file, file is named
like class, with "namespace" directories), then maybe a default
implementation can be provided in SPL's autoload. That way, namespace
imports can be used "out of the box".

Marcus, what do you think?

Regards,

Jessie Hernandez

Best regards,
Marcus

21 years ago by Jessie Hernandez — view source — reply

unread

Hello Marcus,

This simple change will make class imports work out of the box, which is
pretty good. What won't work out of the box are namespace imports. I think
we should provide this also (using the same logic as I'm using in
namespace_autoload.php). Even though this will complicate the default
spl_autoload function, namespace imports would work by default and will be
faster than the userland code. I'll try to add the spl_autoload changes in
my patch in the next few days.

Also, I just looked at the php_spl.c code, is there any reason why .php is
not in the list of default extensions? It'd be nice if the default
extensions were .php, .inc, and .inc.php.

Best regards,

Jessie

"Marcus Boerger" helly@php.net wrote in message
news:13210444107.20050803190850@marcus-boerger.de...

Hello Jessie,

what ever you want auto-of-the-box is good. I suggest the simplest
possible way as default which is we simply stay like we are doing now and
only include a replacement from ':' to the current directory separator.
That we would be searching for '.inc' and '.inc.php' per default in the
include_path directories.

marcus

Tuesday, August 2, 2005, 5:17:45 PM, you wrote:

Forgot to mention, since I expect the majority of users to follow the
PEAR
convention for their classes (basically one class per file, file is
named
like class, with "namespace" directories), then maybe a default
implementation can be provided in SPL's autoload. That way, namespace
imports can be used "out of the box".

Marcus, what do you think?

Regards,

Jessie Hernandez

Best regards,
Marcus

21 years ago by James Crumpton — view source — reply

unread

Maybe I'm alone on this, but all my class files are named as
Classname.class.php... (hint, hint) :)

...

On second thought, maybe it would be interesting/useful to have some mechanism
to allow a formatted string like "%s.foo.php" or "foo.%s.php" to be used by
spl's autoload? Not really sure how it would be implemented... A php.ini setting
;), or from a constant or something. shrug dunno, just thinking out loud.

Jessie Hernandez wrote:

Also, I just looked at the php_spl.c code, is there any reason why .php is
not in the list of default extensions? It'd be nice if the default
extensions were .php, .inc, and .inc.php.

21 years ago by Andi Gutmans — view source — reply

unread

FYI, I haven't had a chance to look at this patch yet (nor a lot of the
emails on the subject). After PHP 5.1 goes RC and we start our Unicode
work, I should have time to look into it. Interesting to see if it
addresses the issues we had in the past. I think some of them weren't
solvable although if this only addresses classes it might have. One note,
we need to make sure we don't complicate the language too much... But
anyway, hopefully next week or so I'll have more constructive feedback.

At 12:07 AM 8/2/2005 -0400, Jessie Hernandez wrote:

Attached is the latest version of the namespace patch! It finally includes
namespace imports and it even includes anonymous namespace support. Also,
the previous bison shift/reduce conflict has been removed. Here is a
summary of its features:

Simple imports: import ns:class1;

Import aliases: import ns:class1 as my_alias;

Namespace imports: import namespace ns;

Anonymous namespaces: namespace { class file_class{} }

Namespace-private classes: namespace ns{ private class prv_class{} }

Two new functions have also been added to support namespace imports (more on
that below):

get_imported_namespaces([$className])
Returns an array of imported namespaces for the current file. If a class
name is passed, and this class is currently being autoloaded (also meaning
that this function is called inside __autoload), then the list of returned
imported namespaces is based on the file that triggered the __autoload
call.

autoload_import_class($className, $namespaceName)
Imports a class in a given namespace for the currently executing file (can
ONLY be used inside __autoload!)

Imports

Imports and namespace imports are handled completely by the user with the
use of the __autloload function. This means that there are no restrictions
on class file naming/directory structure. For simple imports, the class
name will be passed with its full name (including the colons, such as
"ns:class1"). For namespace imports, only the class name will be called.
Since the user needs to determine which namespace (or namespaces) a class
belongs to, the "get_imported_namespaces" function is provided to check the
imported namespaces for the currently-executing file. Once the user is
satisfied with a match, he/she needs to perform an "import" for this class,
but this needs to be done on the executing file, not the file where
__autoload is defined. For this reason, the autoload_import_class function
is provided. A sample usage of both these functions is at
tests/classes/namespace_autoload.php.

Namespace-private classes

Classes marked as "private" from within a namespace can only be used by
classes defined in the same namespace.

Anonymous namespaces

Classes defined inside anonymous namespaces can only be used within the file
that declared the anonymous namespace.

I believe the attached patch solves the issues that were presented long ago
for namespaces. Referring to the post by Daniel Cogwill at
http://www.zend.com/lists/engine2/200304/msg00164.html, the following are
my answers to the problems he found at the time:

import-all silently hides local names.
A: If a global class is defined with the same name as a class in a
namespace, and the namespace class has been imported in the same script,
the global class takes precedence. The namespace class can still be used by
using its full name, i.e. namespace_name:class_name.

Interestingly (and I assume this is simply a bug), functions and classes
behave differently wrt to import-all and duplicate definitions.
A: Irrelevant in this patch.

There is no way to hide names from import (i.e. make a name
non-exportable). This is a fundamental namespace feature, and there is
already an appropriate keyword (private).
A: Namespace-private classes are supported, using the "private" keyword.

The semantic meaning of successive imports depends on their relative
ordering.
A: The engine does not attempt to determine which class is included, the
user decides the most appropriate behavior inside __autoload.

The most egregious issue is that an import in an included file affects
the scope of the including file.
A: Imports in this patch only affect the file they are in.

Since I could not find a way to add the tests/classes/namespace directory
and subdirectories, I zipped them separately, as before.

Let me know if you have any questions on the attached patch.

Best regards,

Jessie Hernandez

21 years ago by l0t3k — view source — reply

unread

Jesse,
another thing to consider (if you havent already) is extension support.
IOW, how do i place my extension-created class into a namespace. Is this as
simple as declaring the class name as Ns:Class ?

l0t3k

21 years ago by Jessie Hernandez — view source — reply

unread

Yep, it's that simple! You can even import it and it'll work! In
zend_lookup_class, the standard class_table search is done first, but on
failure, before it calls __autoload, the class name will try to be
"resolved" using the import table for the executing file. If a matching
entry in the import table is found, then it'll again try to search in
class_table using the full name. Since this class has been defined in the
extension, the search would be successful and __autoload will not be called.

--
Jessie

""l0t3k"" cshmoove@hotmail.com wrote in message
news:FC.7B.04646.FC831F24@pb1.pair.com...

Jesse,
another thing to consider (if you havent already) is extension support.
IOW, how do i place my extension-created class into a namespace. Is this
as
simple as declaring the class name as Ns:Class ?

l0t3k

[PATCH] Namespace Patch, Beta 1 View as Markdown

Imports

Namespace-private classes

Anonymous namespaces

Imports

Namespace-private classes

Anonymous namespaces

Imports

Imports

Regards,

Regards,

Imports

Namespace-private classes

Anonymous namespaces