Programming Languages

Alan Perlis once said: "A language that doesn't affect the way you think about programming, is not worth knowing".

Here are some opinions and facts about a selection of programming languages by Dr Mark Utting (a lecturer in the Department of Computer Science at The University of Waikato).

Topics within this page
Object-Oriented Languages Documentation Generator Tools
Functional Languages Free Implementations
Logic Programming Languages Language Design Issues/Mistakes
Text Formatting Languages (TeX,HTML) XML-related Languages (XSLT etc.)

The Open Directory Project has lots of programming language information.

For examples of programming in 200+ different languages, check out the 99 Bottles of Beer page. The Dylan version is nice, but make sure you check out all the C++ versions too! The template version is amazing!

Another overview of programming and web languages is on test-king.com.

Object-Oriented Languages

The Cetus Team maintains a large collection of links about most object-oriented languages.

Let us start with some lesser-known, but more novel, object-oriented languages, then work down to the well-known mainstream ones.

One of my favourite object-oriented languages is Cecil, by Craig Chambers. It is a multiple-dispatch language that supports both exploratory untyped programming and large-scale statically-typed programming. It includes some new and very expressive ideas (see the paper "Predicate Dispatching: A Unified Theory of Dispatch" by Michael Ernst, Craig Kaplan and Craig Chambers). Cecil is quite similar to the theoretical language that I developed in my PhD thesis.

An equally nice language is Dylan. Like Cecil, Dylan is a safe, strongly-typed, pure object-oriented language that supports multiple dispatch, modules, first-class functions etc. Dylan was originally designed by Andrew Shalit at Apple. There is a commercial implementation of it for Windows 95/NT platforms available from Functional Objects Inc., with a personal version available via free download. Free versions of Dylan for various UNIX machines are available from the Gywdion group. Other useful Dylan sites include:

Python is another favourite. Interpreted, and ideal for knocking up quick prototypes, but with a nice module system, lots of handy libraries, and almost purely object-oriented.

Apart from Simula-67, Smalltalk started the OO craze. Implementations are becoming more easily available now. (See also ObjectShare's non-commercial VisualWorks Smalltalk, available for Linux and Windows) Squeak is an open source Smalltalk that is becoming very popular. A lot of Smalltalk-related information and projects are accessible from the Panasoft Smalltalk Links. Here is a nice Smalltalk tutorial from IBM.

Some other clean OOLs are:

Then we have the less clean C extensions: Objective-C seems less widely used now, but is supported by gcc.

C++ is the most widely used object-oriented language. See: Readings, FAQS, ANSI Standard or here
A recommended book on the design of C++ is

"The Design and Evolution of C++", by Bjarne Stroustrup, Addison-Wesley, 1995.

I quite like the standard template library (STL) of C++ (local docs here). It allows higher-order programming to a certain extent and comes with about 10 generic data structures and 70 simple algorithms over them. See Mumit's STL Newbie guide for some handy STL hints. Other STL-like libraries include: the Graph Template Library (GTL).

There seem to be two major contenders for the "best GUI toolkit" title at the moment. GTK+ (the GIMP toolkit) is more C oriented, but does slots and signals without a preprocessor, whereas Qt uses a preprocessor (MOC) but has the dis/advantage of being a complete solution for porting to Windows 95/NT. The GTK+ toolkit has bindings for several languages, including a C++ wrapper for GTK+ called gtk-- (or FTP).

D is another object-oriented extension of C, designed for systems programming, but with garbage collection, runtime type identification and templates.

Of course, there is also Java which was designed to be safer and cleaner than C++ (see the Java white paper, a Java tutorial, Java Games and Java Puzzles).

[TODO: update this section, now that I've used Java for a few years.]

The two most attractive aspects of Java are that it can be a safe language (all errors are caught by the compiler or bytecode checker or cause runtime exceptions), and its portability (especially its wide range of standard libraries).

Some problems with Java that I've heard about include: hard to format a floating point number, integers etc. are not objects so cannot be subtyped or subranged, non-portable thread semantics, text I/O difficult for beginners. The lack of generics was a real pain in Java (lots of type casting), but now Java 5.0 has fixed this at last.

Here are several interesting extensions/variants of Java:

Objects have also been added onto Perl (Perl 4 was my least-liked language!) and Ada. In fact, Ada was actually the first ISO standardized OO language (Ada95)! A new ISO version of Ada, currently known as Ada200Y, will include Java-like interfaces and a larger predefined library etc.

Rational Software Corporation have done an interesting comparison between development in C and Ada.

Rational Software Corporation also sell Purify (a heap-memory checker) and are responsible for the OO Unified Modelling Language, which is now the industry standard for specifying the structure of OO systems.

Finally, CLU is an old but influential language that introduced important ideas for iterating through collection objects, for exception handling and a carefully-designed theory of object invariants, pre/post conditions etc.

Here are some Software Engineering methods/tools for object-oriented programming:

See John Yeager's S/W Engineering resources for more information.

Functional Programming Languages

Haskell is the most popular functional programming language and is the one that I've used a lot (for example, my Z animator, Jaza). It is an elegant lazy high-level language, with fast compiled implementations plus a interpreter (HUGS) that is good for development. It also comes with a large collection of amazing libraries for writing parsers, pretty-printers, MIDI composition programmes (Haskore) etc., plus the ability to interface to arbitrary C procedures in a functionally clean way.

One of the advantages of Haskell is that expert programmers can extend the language by defining their own operators and 'monads', to get a very concise application-specific language. The disadvantage of this power is that if you overuse it, it becomes difficult for other people to read your programs!

Other popular functional programming languages include the eager (non-lazy) ML family of languages, such as Standard ML and Objective CAML. Here is an introductory book Objective CAML for Scientists.

Logic Programming Languages

There is a WWW virtual library for logic programming. Michael Ley has a database/logic programming bibliography The ALP (Association of Logic Programming) newsletter.

I am part of the Starlog research group, which is designing and implementing a new pure logic-programming language that is especially suited to reactive and real-time programming. Recently, I've implemented a version of Starlog for controlling Lego Robots!

Prolog is the most commonly known logic programming language, albeit impure. A few well-known implementations are: Quintus Prolog, SICStus Prolog, Eclipse Prolog, SWI Prolog (free!). Qu-Prolog is Prolog customised for formal methods (it handles quantifiers, object-variables and substitutions as primitives).

The Prolog at VIP is free for non-commercial use. Another free one is TRINC-Prolog. Michael D. Kersey recommends Amzi! Logic Explorer and the "Adventures in Prolog" (with a "very nice and complete tutorial"). See here for other free Prologs. [mindgap@my-dejanews.com, Alexander.Apostolovski@worldonline.be, and mkersey@metricom.com; comp.lang.prolog, 12Mar99.]

Roman Bartak's Interactive Prolog Guide includes FAQs, program samples, implementations, and references.

The BURKS project provides documentation and free Prolog implementations for DOS, Windows etc.

LPA Prolog for Windows -- with an IDE and single-step debugger -- offers a free 30-day trial. [Nov98]

Amzi! Logic Explorer is free for personal use. It comes with a full tutorial and sample programs, plus a GUI development environment. Amzi! inc. also offers a Prolog compiler and embeddable libraries (for C/C++, Java, Delphi, VB, etc) for a 90-day trial. [Dec98]

Mercury is an elegant, pure, logic programming language from Melbourne University. The fastest logic programming language around...

The Cetus Links OO Prolog page has links to object-oriented logic programming languages. Curry is an extension of Haskell that adds logic-programming features like logical variables, constraint solving and concurrent and distributed programming.

Here are some useful online sites for constraint logic programming:

The quarterly Logic Programming Newsletter is now online.

The textbook Logic, Programming and Prolog (2ed) by Ulf Nilsson and Jan Maluszynski is now available online. It covers theoretical aspects of logic programming as well as practical programming in Prolog, and extensions logic programming such as equational logic programming, constraint logic programming and query answering in deductive databases.

Transformation Languages

Some languages for transforming models and programs:

Text Formatting Languages

LaTeX is the defacto text formatting system for academic papers containing mathematics. There is lots of online reference material for it. See also the Comprehensive TeX Archive Network (CTAN). More documentation is here.

Basser Lout is another text formatting language that produces Postscript/PDF directly and has a more elegant (and functional!) programming/macro language than TeX.

For HTML (the web markup language):

XML-related Languages

Documentation Generators

There are lots of programs available for generating HTML and/or LaTeX documentation from C++ source files etc. For example:

Free Implementations

A Catalog of Free Compilers and Interpreters.

Poplog is an open source, extendable, portable, multilanguage software development environment providing incremental compilers for several interactive programming languages: Pop-11, Prolog, Common Lisp, and Standard ML. It comes with documentation, libraries, and teaching materials for AI and Computer science (and more general programming).

Language Design Issues and Mistakes

Here are a few interesting papers about language design:

Source Code


marku@cs.waikato.ac.nz
Last modified: Thu Dec 19 14:17:59 EST 2013