Review of existing Languages


Preliminary Note

There are a lot of these, ain't it ?
I'd love feedback from you, particularly if you know any interesting language not (or poorly) considered here...
Also feel free (=bound :-) to add your comments and to correct mistypes/broken english.


Contents

  • Existing languages
  • Other language-related WWW pages
  • Why a New HLL



    Existing languages


    Other language-related WWW pages



    Existing Languages


    Agora

    I've been told about this Agora language. Could anyone send feedback ? Here's an FTP site.


    BETA

    BETA is an OO language from those who invented SIMULA. It is the latest advance in OO programming.
    Its only current implementation is the Mjolner BETA system, which is commercial, but with discounts for educational institutions.


    C/C++

    Description

    "C" is a low-level, weakly typed, static, non-modular, non-generic, non-reflective language. The only positive point about it is that it is the one standard as a programming language.

    "C++" is the same, with a huge amount of horrible kludges hopelessly added to cope with "C"'s lameness. It still has the same fondamental misfeatures as "C".
    There are also other less popular "object-oriented" versions of C, such as Objective C or Dynace.

    References

    About C, get the C Bible by Kernighan&Ritchie (the original authors of C). There's also an online tutorial by Dave Marshall, Programming in C.
    About C++, just shoot(yourself.foot++); or if you must, learn to program C++ with the Globewide Network Academy (GNA)'s Introduction to Object Oriented Programming Using C++.
    Look on prep.ai.mit.edu or any mirror site to find GCC, (GNU C Compiler), a free C/C++ compiler, and a lot of utilities written in C.
    Here are papers about why not use C or C++ in general. This one is particularly meaningful as to what a language should be (that C/C++ is not).


    Pros

    1. Anybody knows this language, and we wouldn't have to readapt to another language syntax, as it is the one (now ANSI) standard in system programming (yuck).
    2. We may compile test programs immediately, without having to wait for the kernel and compiler to be done.

    Cons

    Actually, C and C++ are not high-level languages, and just worth throwing to nearest garbage can (poor garbage can), unless you're stuck to it, which you are on existing systems (themselves worth as much, but again, you're stuck to them until Tunes comes out).
    1. C/C++ do not include functions as a first-class object, thus creating a boundary between using and programming: it's a static language; you can't both program and use at the same time. That's the opposite of user programmer/user friendliness.
    2. C/C++ is not a structured language: procedures are all global; that's why C/C++ will NEVER allow having independent light threads, and why it's impossible to have a lightweight multitasking system under C/C++. You may notice that this point is related to the preceding remark: if procedure were objects, you could include them individually inside thread objects, then each thread would have its own independent code.
    3. C/C++ know only early binding (i.e., it only compiles directly executable code), hardly knows about dynamic library linking (that's not a language transparent feature; only a linker feature); C/C++ considers a program to be complete, finished, and run in the absolute without interaction with other programs, but through the system; that's why all ROI in C must be explicitly done through system calls !!!
    4. The "we won't have to rewrite a compiler" argument doesn't stand: if the system is to be OOed, we'll have to adapt the compiler so as it produces OO code compliant to our system's requirements. Unless our system brings nothing that can't be done easily by replacing the standard library, that's impossible; so only front ends can be reused, which are trivial to write.
    5. As it's a low-level language, either we'll have to have low-level specs for the OS (as with Unix), so that we can't adapt to an architecture different from that for the which the OS was designed; or we'll have to rewrite a great amount of the C/C++ code on each system adaptation. So we lose either system functionality, or language portability. Interoperability of code is also impossible, unless we define a common target architecture that other computers will have to emulate.
    6. For the same reason (C/C++ being low-level), we can never achieve object-level security, but by having a C/C++ program for each object, which either disallows everything -however little- is an object in the system, or requires many a low-level system (as opposed to language) declaration in a C source, and/or requires having tiny C/C++ programs, which contradicts the heavy compilation cost and the class philosophy of the language.
    7. Horrible in C and dreadful in C++ is the lack of really first-class structured values. This makes C is really nothing more than a badly specified portable assembler (with very limited macro facility and restrictions in calling convention), and gives a completely obfuscated notion of object identity to C++.
    8. The C++ philosophy contradicts the idea of late user-object binding. C++ knows only of early compile-time object binding, or at best/worst binding with compile-time defined virtual class realization through virtual tables. So to make the slightiest add/change, you must recompile the whole app.
    9. Because the whole object system in C++ is based on inheritance, enhancements in a program may mean complete rewrite of the type hierarchy.
    10. The C++ preprocessor allows simple macro-definitions, but neither macro instructions, nor recursive macro definitions. If #define DEF #define was possible, for example, it would be possible to Ziv-Lempel compress a source program from C to C. But cpp just plain sucks.
    Note that "C" offers absolutely no particular interest when cut from all its standard compilers and libraries, for you can no more port existing software. As Tunes won't support any standard "C" library (at least as support for native code), and requires a different compiler anyway, because its semantics is so much different, "C" offers no interest on top of Tunes. Thus, "C" just has nothing to do with Tunes, except perhaps as a layer between Tunes and a POSIX compliant system, if Tunes is to be implemented as an application under such system (see OTOP subproject).


    Concurrent Agregates

    Concurrent Agregates is a language for distributed computing developped by the Concert project in Illinois.


    CECIL

    Cecil is an OO language from the same person who invented SELF, at University of Washington.


    Clean

    Concurrent Clean is a general purpose, higher order, pure and lazy functional programming language for the development of sequential, parallel and distributed real world applications.

    Clean is a language in the spirit of other modern lazy functional languages like Haskell and Miranda. People familiar with these languages will have no difficulty to program in Clean. The Clean compiler has the nice property that it runs on small platforms (Mac, PC, Sun), while it compiles very quickly and produces code of state-of-the-art quality.


    Common LISP

    Description

    LISP is a self-extending higher-order strongly typed dynamic strict (but with lazy constructs) functional language. It's one of the oldest programming languages, but also one with the nicest semantics also. It's a good experimental platform for just any kind of computing; it has got very good support, including free portable development environments, integrated structured editors, and efficient "optimizing" compilers. Unhappily, it suffers from flaws deep enough to preclude its use by the non-hacker :( :( :( :(.

    There seem to be two standards as for LISP: Common LISP is a huge monolithic language, with hundreds of built-in constructs for a megabyte worth of run-time system (not talking about add-on modules). Scheme is a minimalistic, "skimmed", version of LISP, in which everything built upon the simplest constructs.

    In LISP, everything is parsed as S-exp's (Symbolic EXPressions), which are indeed balanced parenthesized expressions of atomic symbols. These S-exp are trivially translated into structured data, which is interpreted very easily. The basic constructor is the (syntactically parenthesized) list of S-exp's, and a list is evaluated by first evaluating each element, then applying the function denoted by its first element to the rest of the list as arguments.
    LISP is really a nice language, but S-exp's are annoying to the non-hackers (particularly if you don't use a LISP editor like EMACS that will help you balance your expressions). Actually, the S-exp's are LISP's only, but deep flaw: if LISP had a freeer syntax, it would fulfill all the requirements for (a basis to) Tunes' HLL. LISP would truely be the one universal language but for that !

    References

    There are lots of books about LISP and Scheme. About LISP, you may get the specifications for the Common LISP ANSI standard, CLtL (Common LISP, the Language). A great book about programming in Scheme, but that actually teaches programming in general, is the SICP, Structure and Interpretation of Computer Programs; just great.
    GNU Emacs is a widely spread LISP-based IDE. Look on prep.ai.mit.edu or any mirror site to find EMACS.
    There are also newsgroups about LISP and Scheme, comp.lang.lisp, comp.lang.scheme, not to talk about the many groups about emacs or ai.
    [Note: I should ask JCh and/or HBaker for pointers about these...] (Other machines at ?) MIT is also where you could find anything about
    LISP and Scheme repository here


    Pros

    1. It's a idely known and standard language, with implementation on just any computer architecture, including very portable ones.
    2. We may test programs immediately, without having to wait for our kernel to be done.

    Cons

    1. it has got a poor type system
    2. it allows too many side-effects
    3. no standard reflectivity allows the syntax to go beyond S-exp's
    4. it lacks some ML-like pattern matching
    5. it lacks a clean macro system
    6. its standard (common lisp) has got too many features nobody uses.
    7. its module system offers no security at all.


    COBOL

    COBOL means COmmon Business-Oriented Language. It's a very old and lame language which has got a FAQ here.


    Coq

    Coq is a higher-order proof system based on the Curry-Howard isomorphism between propositions and types, proofs and terms in a pure functional language: a functional term is a proof of its type's realizability. By restraining to intuitionistic logic (i.e. no built-in choice axiom), it allows to extract actual programs from proofs.
    The newer version of Coq does have programmable tactics (using CAML), extensible grammars, etc.
    The problem with Coq is that it is not reflective: there is a one global meta-context, and no way to meta-translate expressions: a proof done in "Prop" will have to be done again in "Set" and in "Type"; there are no "proof sketches" as first-class objects.
    Coq has got a WWW page, which is no more empty.
    The Coq distribution includes full docs.


    Dylan

    Apple is developping Dylan, an object-oriented dynamic language to replace C++, whose semantics is like a good OO LISP, but with a much nicer syntax as well as semantics.
    CMU is already developping a free clone, Gwydion.


    Ellie

    Description

    Ellie is a language designed for computer-scheduled parallelism, which stresses the existence of future values, that the system may lazily or concurrently evaluate.

    References

    You may find papers about it here

    Pros

    1. It has unified semantics for objects (code&data)
    2. the same for parallelism
    3. it has already been studied

    Cons

    1. it's got a cryptic syntax
    2. it's not standard and we don't own it; a compiler may be difficult to have.
    3. It's got almost no "no". No negation, exclusion and such, but in the function/operation assertion, so the compiler cannot understand things as simple as "this object can take these values, and NO other.
    4. no exceptions to cope with the previous: these would be useful for handling errors or special cases, but would be very difficult to design consistently with parallelism.


    Escher

    Escher is a declarative, general-purpose programming language which integrates the best features of both functional and logic programming languages. It has types and modules, higher-order and meta-programming facilities, and declarative input/output.
    Escher also has a collection of system modules, providing numerous operations on standard data types such as integers, lists, characters, strings, sets, and programs. The main design aim is to combine in a practical and comprehensive way the best ideas of existing functional and logic languages, such as Gödel, Haskell, and \lambda-Prolog. Indeed, Escher goes well beyond Gödel in its ability to allow function definitions, its higher-order facilities, its improved handling of sets, and its declarative input/output. Escher also goes well beyond Haskell in its ability to run partly-instantiated predicate calls, a familiar feature of logic programming languages which provides a form of non-determinism, and its more flexible handling of equality. The language also has a clean semantics, its underlying logic being (an extension of) Church's simple theory of types.
    You can obtain a report. about it.


    FORTH

    The main on-line source of information about FORTH are the homepage of the FIG (Forth Interest Group), and this page.
    Of course, the place to ask questions about FORTH is the usenet newsgroup comp.lang.forth.
    Here is an online book, "Real-Time Forth",
    FORTH, inc is the company created by the original authors of FORTH.
    Some implementations:


    Gema

    Gema is a general purpose macroprocessor.


    Haskell

    Haskell is a lazy functional programming language. See this FTP repository.
    There's a Haskell group at Glasgow head up by Simon Peyton Jones with its own implementation GHC
    Professor Paul Hudak is heading up the Yale Haskell group, and doing Haskell and music in Haskell.


    Java

    Java is a C-like OO language whose existing compiler compiles to bytecodes. It can be found here. It is meant to be used as an description language for objects passed accross the WWW. Here is an FTP site.


    Linda

    Linda is a language for parallel programming.


    MISA

    m4 is a powerful macro-expansion program designed as a preprocessor to more stubborn languages. It's ugly, but it's fairly standard (available on most platforms, including a GNU version).


    MISA

    MISA is an interesting project to design the language of next century.


    ML

    ML (originally the Meta Language for a theorem prover) is a class of (strongly) typed functional language.
    ML comes in two main flavors:
  • SML, with its docs and implementations SML/NJ, Edimburgh ML, Moscow ML, and
  • CAML, with its implementation CAML-Light and On-line docs
    Here are some interesting software projects using ML:
  • The Fox project from CMU to write an OS using (an extension to) SML.
  • The Coq project of a constructive proof/program environment.


    Modula-3

    Modula-3 comes between Modula-2 and Oberon in Niclaus Wirth's quest for his ideal language...
    Click here for more information.


    Napier88

    Napier88 is a persistent programming system from University of St Andrews


    Oberon

    Oberon (now version 2) is the latest modular OO language by Niclaus Wirth (the author of Pascal and Modula) (also here).
    There are FTP sites for Oberon and the Oberon User-group.


    Orca

    Orca is a language for distributed computing, codevelopped with the Amoeba distributed OS.


    Pascal

    Pascal was a toy written by Prof. Nicklaus Wirth to teach computer languages. Unhappily it has been taken seriously by many people.
    See Modula-2, Modula-3, and Oberon for more serious languages developped by Professor Wirth.
    Brian Kernighan (author of C as well as many Pascal software), once wrote an article "Why Pascal is Not My Favorite Language", which is quite obsolete now that modern Pascal's (e.g. Turbo-Pascal) are quite equivalent to C (which also shows C sucks as much as this toy Pascal language).


    Perl

    Perl is a scripting language for easily manipulating text, files, and processes. It provides easy ways to do many jobs that were formerly accomplished (with difficulty) by programming in C or one of the shells. And here's a Perl 5 page for people on the bleeding edge.


    Prolog

    Prolog is a language for programming based on propositional logic (not even first-order logic).


    Python

    Python is an OO programming language
    WWW and FTP sites.


    RPL

    RPL ("Reverse Polish LISP") is the language from HP 28/48 calculators. Despite their lack of horsepower, these calculators are much more usable and friendly than my unix workstation. Let us try to determine why...

    Pros and Cons

    Pros

    1. The language is reflective: code IS an object as anything on the HP, and it is easily manipulable.
    2. Interaction is done through a visible stack in exactly the same way as the thing is programmed. The interface is thus very well integrated with the programming language, and the interface concepts are simple, with trivial automatization. Much better than windows !
    3. The system is orthogonally persistent.

    Cons

    1. The language was not extensible (well HP48's can be extended using the assembler, but that seems kludgy).
    2. The language was designed with a unique execution context in mind: single user, single-threaded, global variables.
    3. No support for modules and migration.


    Sather

    Sather is a free Object-Oriented programming language rival of Eiffel.


    Scheme

    Scheme is a small dialect (some say a skimmed version) of the LISP language.
    Scheme has got a WWW page at the MIT, and you can find more info about Scheme in the Scheme FAQ, from the comp.lang.scheme newsgroup.
    The Scheme Underground project to build a complete computing system on top of Scheme48, a portable implementation of Scheme. Scheme
    Object-Oriented systems have been implemented in Scheme:
  • OScheme Objective Scheme from INRIA
  • Moostrap (a Self-like language with behavioral reflection)
  • Ken Dickey's YASOS (Yet Another Scheme Object System)
    STk allows access to the popular Tk toolkit for X programming via Scheme


    SELF

    SELF is a Object-Oriented programming language based on very simple concepts which allow efficient implementations.
    SELF uses trivial strong typing (much like LISP): there is no "typecasting" backdoor to object representation, but there is no type hierarchy.
    Brown University has an interesting course on SELF.
    The Merlin project uses SELF.


    TCL

    TCL is a lame interpreted language, which is popular because of Tk, a powerful toolkit to program the X-Window environment.
    Many better languages, including Perl and Scheme have access to Tk. And other languages have other interfaces to GUIs.
    Comparisons of Tcl with other systems



    A new HLL

    Pros and Cons

    Pros

    1. We can design the syntax to fit our needs and ideas, so that it's much easier to use. Moreover, even C isn't our natural language, and whatever language we use, there will have been adaptating time to use it.
    2. We can correct the lacks of any existing language we would have used.
    3. Portability: both the system and the language may be as easy to port. All you need do is porting a LLL compiler back-end or interpreter, and hardware specific lolos (low-level objects).
    4. The language is perfectly well adapted to the system. No need of bizarre and slow language -> system call translation.
    being efficient as an interpreted language, it may serve as a shell language as well as a programming language; being powerful, and easy to specialize via standard libraries, it also replaces small utility languages (sed, awk, perl, etc); finally, being high-level and knowing of relations between objects, it is easily adaptated to an AI language. So there is no more need to learn a different language for every application; the same language is used for (almost) everything; no more need to learn new syntaxes each time.

    Cons

    1. we have to relearn a new language syntax. But as we may choose whatever syntax pleases us (and support multiple automatically translatable syntax), this is no great deal, really.
    2. No existing compiler can be used directly. This is no great deal either: Front end are easy to write, and no existing back end can fit an interestingly new OS' object format, calling conventions, and security requirements. Moreover, our system having a brand new conception, even with a traditional language, we'll have to learn restrictions about our way of programming.
    3. we have to debug the language specifications as we use it. But this can prove useful to refine the language and the system specs. Here is an interesting point.


    Draft


    To Do on this page

  • Create a subdirectory for the Review alone.
  • Melbourne's Mercury.
  • Tim Budd's Leda.
  • OO Info.
  • Have a subfile for each language family.
  • Find all existing HLLs.
  • Write a summary about each of these, with particularities, pros, cons, pointers, (examples/history ?), etc.
  • Add references to the Glossary.
  • Wait for feedback and criticism.
  • Instead of this bogus classification, use actual criteria:
    • strongly typed or not
    • type-dependent types
    • value-dependent types
    • dynamic/static language
    • garbage collection
    • single-dispatch/multidispatch polymorphism
    • first/second/higher order
    • prefix/infix/postfix syntax
    • reflectivity
  • Shall we point to the NASM project for a freeish assembler ???


    Back to the Tunes Review Subproject,
    or to the HLL Subproject.


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    Faré -- rideau@clipper.ens.fr