Re ANN: A new scripting language Tao 0.9.0 beta released!

[Fu Limin]

In what ways is your language distinctive?
Well, I think the most distinctive feature is the integration of powerful
text processing ability and powerful numerical computation with a
simple syntax for them. I also try to support a simple and transparent
interface to C++. Though there is still a long way to go, I think the
status of Tao is promising, in fact I already benefit from it in my
research where both text processing and numerically computation are
important, for which I "suffered" a lot from using Perl in the beginning,
which drived me to design my own one ^_^

How does developing your own

language (as opposed to making stronger one of the languages whose
newsgroups you've posted to) make the sum of human experience richer?

For the existing languages, I think they have already stabilized a kind of
philosophy, and something have already got complicated. So I think it
would be more difficult for me to dive into them. Anyway, I believe it
worth trying to design a new language, if I found it more usesful in some
work than the other languages, somebody will also find this. A new option
is not bad thing.

And do any of these observations/questions below help you explain these
larger matters? :^)

Yes, thank you for your time to make these observations/question and
suggestions.

Odd things I've noticed in a quick trawl through your docs:
* What no bit-ops? And why give ^ a non C/C++ meaning?

My using of ^ as power is influenced by Matlab. In the beginning I didn't
know it is also used in C/C++.

* What sort of characters are you using?

For strings, I use stl::string, so I didn't care about this.
But for byte type numeric array, I used unsigned char.

* How does passing by reference square with constant arguments?

In Tao constants are also represented by objects, their passing by reference
are the same as other types of objects.

* Your I/O interface has a /long/ way to go!

Right. I haven't concentrated on this part. The status of IO support
deosn't conform to the version number which increased too rapidly

* The complex number and matrix stuff seems reasonable.

Yes, this is one of the important features I intended to have in Tao.
In fact, I spent much time on implementing them, and they contributed
to half of the size of the compiled codes. I believe this part is one
of the best implemented part. Some of the operations for numeric
arrays are even more convenient than Matlab. Now a very simple
and transparent interface is supported to pass numeric types to and
from C++ modules, so the next step to support powerful numeric
computation in Tao is to find somebody or by myself to write
bindings to some commonly used numerical packages.

* It is probably a good idea to add something like a C/C++ switch; it
might only be syntactic sugar around if, but good syntax makes a
difference.

Yes, I will do it.

* Given that you are using mutable objects, do you have a way for
someone to force a duplicate of an arbitrary object? That would make
doing things like security separation much easier.

If you mean data object, yes, but it's not available for users yet. Now it is
mainly used for passing Tao data types to C++ modules, where each Tao
object can be copied and converted into its C++ equivalent object
(though internally they are all C++ objects, but the object used in C++
modules is different from the one used in Tao interpreter, e.g. TaoHash is
used in the interpreter, while TcHash is used in C++ module, the conversion
or copying keep its structure including cyclic ones).

But for class or routine objects, no, I will support this when I started to
support multi-threading.

I should point out (since I am afraid I misunderstood something
of you in this point), the assignment in Tao is simpily a new binding
of object to pointer even if the objects in two side of assignment are
or the same type (except for assign new values to numeric array elements).

* The ~~ operator is neat.
* Do you have some kind of subtype operator?

Not yet. Yes, I should support it, it can be useful for checking
type of numeric arrays and objects of Tao class. Though now
Tao can well check the types of two objects are the same or
different, e.g., if aa is an object of class AA and bb is an object
of class BB, aa=?AA, bb=?BB, will give true, and aa=?bb will give
false.

* Are classes, namespaces and modules all objects? Can you introspect
on them to discover what exists and what you can do with them?

Yes, they are all objects. But no mechanism is provided to introspect
them, I had thought about supporting this, but it simply slipped my mind.
You remind me ^_^

Best regards,

Limin

 

[Donal K. Fellows]

Well, I think the most distinctive feature is the integration of powerful
text processing ability and powerful numerical computation with a
simple syntax for them. I also try to support a simple and transparent
interface to C++. Though there is still a long way to go, I think the
status of Tao is promising, in fact I already benefit from it in my
research where both text processing and numerically computation are
important, for which I "suffered" a lot from using Perl in the beginning,
which drived me to design my own one ^_^

Ah, the dilemma between whether to create your own or extend what is
already there. Myself, I prefer the second option because that lets more
people use it with a lower overhead; the barrier to entry on an entire
programming language is quite a bit higher even if the integration it
affords you is more closely tuned.

For the existing languages, I think they have already stabilized a kind of
philosophy, and something have already got complicated. So I think it
would be more difficult for me to dive into them. Anyway, I believe it
worth trying to design a new language, if I found it more usesful in some
work than the other languages, somebody will also find this. A new option
is not bad thing.

Every programming language is really a different way of thinking about
programming problems. The hard bit is determining whether you're either
covering some new fraction of the noosphere, or if not, covering some
useful distinct subset of it instead. It is also a curiosity that
sometimes reducing the number of things you do can make a language more
suitable for some kinds of tasks (security often seems to work out that
way for some reason).

[Below, where I've not replied to some point made, it's because I don't
feel I have anything more to say on the matter at the moment.]

My using of ^ as power is influenced by Matlab. In the beginning I didn't
know it is also used in C/C++.

An alternative would be to use ** for exponentiation, deriving from
Fortran, and give the bit-ops their conventional C/C++ meanings.

For strings, I use stl::string, so I didn't care about this.
But for byte type numeric array, I used unsigned char.

The real Q here is chars vs. characters. :^)

In Tao constants are also represented by objects, their passing by reference
are the same as other types of objects.

So, that would mean that it is possible for a constant to be altered? My
goodness me, that reminds me of some awfully buggy code I've seen in the
past! Please make sure that you can't ever change the actual constants
that come from your program (setting 0 to 1 is a good way to make things
go belly up!)

Right. I haven't concentrated on this part. The status of IO support
deosn't conform to the version number which increased too rapidly

Concentrate on producing a system for externally-defined loadable
modules and put (most of) your IO code in one of those. :^) Some people
have had real success with doing that.

If you mean data object, yes, but it's not available for users yet. Now it is
mainly used for passing Tao data types to C++ modules, where each Tao
object can be copied and converted into its C++ equivalent object
(though internally they are all C++ objects, but the object used in C++
modules is different from the one used in Tao interpreter, e.g. TaoHash is
used in the interpreter, while TcHash is used in C++ module, the conversion
or copying keep its structure including cyclic ones).

Firstly, control of when things get duplicated is very important,
because doing a deep copy of a large object graph can be expensive. The
easiest way to handle this would be to put in a monadic operator that
duplicates an object.

Secondly, is it really necessary to have TaoHash and TcHash as separate
things? Unifying your entity system might be a big win over the longer term.

Donal.

 

[Fu Limin]

Ah, the dilemma between whether to create your own or extend what is
already there. Myself, I prefer the second option because that lets more
people use it with a lower overhead; the barrier to entry on an entire
programming language is quite a bit higher even if the integration it
affords you is more closely tuned.

You can see the reason why I chose the first in my reply to Josef
'Jupp' SCHUGT in comp.lang.ruby group.

Every programming language is really a different way of thinking about
programming problems. The hard bit is determining whether you're either
covering some new fraction of the noosphere, or if not, covering some
useful distinct subset of it instead. It is also a curiosity that
sometimes reducing the number of things you do can make a language more
suitable for some kinds of tasks (security often seems to work out that
way for some reason).

Yes, that's why I mostly concentrated on both regular expression and
numeric
types and operation.

[Below, where I've not replied to some point made, it's because I don't
feel I have anything more to say on the matter at the moment.]

My using of ^ as power is influenced by Matlab. In the beginning I didn't
know it is also used in C/C++.

An alternative would be to use ** for exponentiation, deriving from
Fortran, and give the bit-ops their conventional C/C++ meanings.

Yes, this can be done. I didn't use Fortran for long time, I really
forgot there is such an alternative as **

The real Q here is chars vs. characters. :^)

Sorry, I don't understand what you mean by chars vs. characters.
Do you mean the encoding?

So, that would mean that it is possible for a constant to be altered? My
goodness me, that reminds me of some awfully buggy code I've seen in the
past! Please make sure that you can't ever change the actual constants
that come from your program (setting 0 to 1 is a good way to make things
go belly up!)

If you mean constant variable, yes, otherwise no(for constant
value,strings).

When a constant value is passed as parameter to functions, a new object
is created to contain the value. But they are really created only when
necessary, the interpreter takes a strategy to avoid unnecessary
allocation
of new objects. (Maybe this is the real answer you wanted)

For example:
routine routA(a){ print(a); }
routine routB(a){
b={};
b.insert(a);
}
for(i:=0;i<10;i++){ routA(222); }
for(i:=0;i<10;i++){ routB(222); }

In the first loop, only one object is created in the beginning,
the same object is used in the following cycles, because that
object is not assigned to any variable or inserted to any array,
so the its reference count will not change, this means it is still
"free" for following use.

While in the second loop, new objects are created, because insertion
of them to an array will increase the refCount of newly created
objects.

But constant variable can be changed only if there is the keyword
"const"
precede that variable, which means to re-initialize it. So the the
program
will not alter a constant variable by mistake. If it is necessary, this
can
also be changed.

Concentrate on producing a system for externally-defined loadable
modules and put (most of) your IO code in one of those. :^) Some people
have had real success with doing that.

Good suggestion, it's my second time hear this kind of suggestion,
I will do it in this way, so the basic IO will be built-in
while advanced IO will be provided as modules.

Firstly, control of when things get duplicated is very important,
because doing a deep copy of a large object graph can be expensive. The
easiest way to handle this would be to put in a monadic operator that
duplicates an object.

Yes, in Tao objects are copied only when they passed to a function
from external modules, even in this case, the real data of numerical
arrays are _NOT_ copied, only the pointers are passed.

Secondly, is it really necessary to have TaoHash and TcHash as separate
things? Unifying your entity system might be a big win over the

longer term.

It really depends. TcHash is only used for external C++ modules as a
bridge
to pass data from and to C++ modules. The reason why I don't want pass
TaoHash directly is that, to pass TaoHash, it means Tao must provide
additional library to C++ modules for linking, and in Windows there
could be some problems for this since STL and static variables are
used.

To provide TcXyz, only minimum interfaces are provided and can be put
in a single header file. In this way it's possible to develop C++
modules
for Tao with only two header files, nothing else!