On 9 d?c, 02:32, Leigh Johnston<le...@i42.co.uk> wrote:
On 08/12/2010 21:34, red floyd wrote:
On Dec 8, 12:42 pm, Leigh Johnston<le...@i42.co.uk> wrote:
On 08/12/2010 20:19, Keith H Duggar wrote:
On Dec 8, 12:05 pm, Leigh Johnston<le...@i42.co.uk> wrote:
On 08/12/2010 16:59, Yannick Tremblay wrote:
So for example, although I do not beleive that there exists a number
of lines per functions that is the threshold between a bad and a good
function, in some evironment, it can be worthwhile to place a rule
that say that all "all functions must be less than XX lines unless a
good explanation is provided".
Why provide a good explanation? Functions that contain switch
statements are often long and require no explanation. The following
function of mine is over 100 lines long and requires no explanation:
[snip unbelievably naive and primitive mess]
Wow ... just wow ... that is a prime(evil) example of the horrific
code that poorly trained fanboys write when they lose all (or never
had any) rational perspective on code readability.
It's exactly the kind of stuff you see all over Micros$$t code so
I guess it's not so surprising in your specific case; but ... wow.
You are right about one thing though, no explanation should be
provided in this case. Instead the code should be instantaneously
rejected and the programmer sent to rehab.
There is nothing wrong with the constructor I posted. It contains no
branches (is therefore very simple) and all it does is construct objects
which is generally what constructors do. It is also perfectly readable.
and it would be much clearer if it was table driven. All that nasty
inline stuff could be replaced by a loop and a table.
Just to show that I am not immune to constructive criticsm (and to shut
the trolls up) I decided to rewrite the constructor so it uses a table
and luckily the use of templates made sure it wasn't too tedious:
[snip]
Actually, I'd rather have a builder pattern:
// stores names functions
struct NamedFunction
{
std::wstring iName;
struct normal
{
normal(function* (*aCreator)()) : iCreator(aCreator) {}
function* (*iCreator)();
};
struct stdlib
{
// snip for brevity
};
typedef lib::variant<normal, stdlib> type_t;
type_t iType;
};
// stores namespace and their functions
struct NamespaceRepository
{
std::wstring iNamespaceName;
std::vector<NamedFunction> iMemberFunctions;
NamespaceRepository( std::wstring const& name )
: iNamespaceName(name)
{}
};
bool operator<(NamespaceRepository const& lhs, NamespaceRepository
const& rhs )
{
return lhs.iNamespaceName< rhs.iNamespaceName;
}
// persitancy root for namespaces
struct ByteCodeRepository
{
std::set<NamespaceRepository> _namespaces;
// builder of namespace list or related functions
struct Builder
{
mutable std::set<NamespaceRepository> _namespaces;
mutable NamespaceRepository * iNamespaceRepository;
Builder()
: iByteCodeRepository ()
, iNamespaceRepository()
{ }
Builder const& addNamespace(std::wstring const& name) const
{
iNamespaceRepository =&(*_namespaces.insert(name).first);
return *this;
}
template<typename T>
Builder const& addNormalFunction(std::wstring const&
name ) const
{
assert( iNamespaceRepository );
NamedFunction func;
func.iName = name;
func.iType = NamedFunction::normal(new T()); // or
whatever
iNamespaceRepository->push_back(func);
return *this;
}
template<typename T>
Builder const& addSystemFunction(std::wstring const&
name ) const
{
// ....
return *this;
}
};
ByteCodeRepository( Builder const& builder )
{
_namespaces.swap(builder._namespaces)
}
};
And then you can define:
ByteCodeRepository repository = ByteCodeRepository::Builder()
.addNamespace(L"")
.addNamespace(L"system"),
.addNormalFunction<wait_1>
( L"wait" )
.addNormalFunction<wait_2>
( L"wait" )
.addNormalFunction<create_thread_1>
( L"create_thread")
.addNormalFunction<create_thread_2>
( L"create_thread")
.addNormalFunction<send_object_1>
( L"send" )
.addNormalFunction<send_object_2>
( L"send" )
.addNormalFunction<post_object_1>
( L"post" )
.addNormalFunction<post_object_2>
( L"post" )
.addNormalFunction<available>
( L"available" )
.addNormalFunction<which>
( L"which" )
.addNormalFunction<get>
( L"get" )
.addNormalFunction<resource::file_open>
( L"open" )
.addNormalFunction<resource::file_read_1>
( L"read" )
.addNormalFunction<resource::file_read_2>
( L"read" )
.addNormalFunction<resource::file_read_line>
( L"read_line" )
.addNormalFunction<resource::file_write_1>
( L"write" )
.addNormalFunction<resource::file_write_2>
( L"write" )
.addNormalFunction<resource::file_write_line>
( L"write_line" )
.addNormalFunction<resource::file_seek_read_1>
( L"seek_read" )
.addNormalFunction<resource::file_seek_read_2>
( L"seek_read" )
.addNormalFunction<resource::file_tell_read>
( L"tell_read" )
.addNormalFunction<resource::file_seek_write_1>
( L"seek_write" )
.addNormalFunction<resource::file_seek_write_2>
( L"seek_write" )
.addNormalFunction<resource::file_tell_write>
( L"tell_write" )
.addNormalFunction<resource::file_is_good>
( L"is_good" )
.addNormalFunction<resource::file_close>
( L"close" )
.addNamespace(L"text"),
.addNormalFunction<tokens> ( L"tokens" )
.addNormalFunction<to_utf8> ( L"to_utf8" )
.addNormalFunction<from_utf8> ( L"from_utf8" )
.addNamespace(L"math"),
// ...
;
};
Hereafter it is not too hard to make a loop for registration.
But I agree that if it doesn't make sense to keep it afterward, you
could put that in a function and it can exceed the XX lines limit.
--
Michael