This document lists some of the programming languages I have used or investigated (played with) over the years. It is a very personal view and sometimes the views expressed will appear contradictory or even downright quirky. That's because they reflect the author's state of mind at the time of using the particular language!
The layout arranges the languages into groups:
Where it makes sense I will present a 'Hello World' program in the language.
In this context "production" means that I got paid for doing the work and/or that several other people are using the resulting program. It also means that the programs were developed using industry standard software engineering practices for design and documentation etc.
When I first started using C (on a vacation project while at university) it came as a breath of fresh air after the restrictions of ANSI Pascal. It allowed fast expression of ideas with just enough type checking to let you know if you're being stupid but not enough to suffocate as Pascal did. It also meant excursions into Assembler were limited to those few areas where Assembler was fun!
A few years later I migrated to C++ but over time I now find myself using C++ as a better C and even occasionally preferring the original. C++ cranks up the type checking to near Pascal levels and adds whole wadges of new features which complicate the language and slow the compiler.
C remains one of my favourite languages and its not a coincidence or surprise that the OS everyone is talking about - Linux - is written in vanilla C and not C++.
#includevoid main() { char* msg="Hello World!"; /* similar idiom as OO examples */ puts(msg); }
C++ is C with bells on. Initially the bells tinkled occasionally and made sweet music. Now there are so many bells you can't hear the music for the noise! (And some modern C++ programs look like noise too!)
I have a great admiration for C++ and for very large systems or environments where many different modes of design/programming are practiced it is peerless. Unfortunately that flexibility is also its downfall. It has become almost impossible to program well in C++ without an intimate understanding of its internals, which is ironic given that one of its primary design aims is to allow the programmer to work at a greater level of abstraction.
#include <string.h>
#include <stdio.h>
class Message // define a message class
{
private:
char msg[50];
public:
Message(char* s)
{strcpy(msg,s);};
void print()
{puts(msg);};
};
void main()
{
m = new Message("Hello World!");
m->print();
delete m;
}
Delphi isn't really a language, its an environment. But everyone tends to call the language within that environment Delphi too so I'll roll with the flow!
The real name for the language of Delphi is Object Pascal and it is a (widely divergent) version of the language Apple used to program the first Macs. This in turn added OOP features to standard Pascal. (A fuller description and demo of Apple style OP is found in Booch's OOAD 1st edition c1992)
Essentially Delphi's brand of OP adds the best features of C++ to Pascal but without striving for total backward compatibility or no compromise performance etc. This results in a much more human readable and simpler language. For serious windows programming OP is my language of choice ad the Delphi environment is the best IDE I've used so far. (I'm currently on V3 although V4 is the latest version at the time of writing)
program hello;
{---------Class definition ---------}
type
class=TMessage
msg : String;
public:
constructor Create(s : String);
procedure Print;
end;
constructor TMessage.Create(s : String);
begin
msg := s;
end;
procedure TMessage.Print;
begin
writeln(msg);
end;
{------------End class -----------}
var m : TMessage //declare instance reference
begin
m := TMessage.Create('Hello World'); // create instance
m.Print;
m.Free;
end.
COBOL is one of the earliest computer languages appearing in 1959, just one year after me! It is one of the latest computer languages that I have used however but no better for that! It is not a popular language amongst programmers and despite trying to maintain a neutral stand, I can only agree with the consensus. COBOL has a few good features especially those specific to its bread and butter tasks of data processing, number crunching and file handling. In particular its report writing capabilities outshine its contemporaries and its file handling is quite simply the best in the game. These don't, however, make up for its negative characteristics: uppercase letters, fixed position keywords and verbosity bordering on the insane. I will be quite happy never to have to work with COBOL ever again.
IDENTIFICATION DIVISION.
PROGRAM-ID. HELLO-PROG.
*******************************
ENVIRONMENT DIVISION.
CONFIGURATION SECTION.
SOURCE-COMPUTER. IBM-PC.
OBJECT-COMPUTER. IBM-PC.
********************************
DATA DIVISION.
********************************
PROCEDURE DIVISION.
DISPLAY-PARA.
DISPLAY "HELLO WORLD FROM COBOL!".
END-PARA.
STOP RUN.
The definitive description of little languages is in a series of articles published in Dr Dobbs journal and the ICM. In particular I recommend the Programming Pearls series of books by Jon Bentley. In the context of this discussion I really mean scripting languages ans some of these have actually become pretty big!
The first little language I came across and still a favourite. It does a conceptually simple job simply and reasonably fast. Everyone should learn awk.
The key principle of operation in awk is pattern matching. Awk reads a text file line by line searching for patterns. When it finds a pattern that it recognizes it performs whatever action(sub-routine) has been defined - the default being to print the line. An Awk program thus consists of a set of pattern/action pairs. Typical uses are to extract columns from a data file, or to produce summary reports etc.
Note: This version prints "Hello World" every time "Hello" or "hello" is found in the input file, and gives a success count at the end.
#!/bin/awk
BEGIN {msg="Hello World"}
/[Hh]ello/ {print msg; count++}
END {print "Hello was found ", count, "times in ", FILENAME}
The flavour of the last few years, never mind month, and very powerful. Pity it reads like line noise, and on a very dodgy line at that!
I have never quite got my head round Perl - I can see the power but it just offends my senses somehow. Everything just looks a bit too much like its been stuck together with sticky tape and glue rather than coherently designed. (Its OO mechanism in particular!)
What cannot be denied is that the WWW is driven by Perl to a very large extent and if you are curious then don't let me stop you! Instead visit: http://www.perl.org
$msg = "Hello World"; print $msg;
Perl for purists, especially OO purists. I love it to bits!
Python is object oriented throughout, it has an extensive module system and is designed to allow scripting on a large scale. Although much less well known than Perl you can achieve pretty much the same results for the same effort in Python as you can with Perl - and you might even understand the resultant code 6 months later.
#!/local/bin/python
class Message:
def __init__(self, str="No message provided"):
self.text = str
def print(self):
print self.text
if __name__ == "__main__":
m = Message("Hello World")
m.print()
sh,csh,tcsh,ksh,bash. Pick your favourite. A command prompt with real power. You can do if, case, while and for loops. You can test for file type(directory, system file, access etc) There's command history access, filename and command completion, executing jobs in foreground or background etc etc.
#! /bin/sh message="Hello World" echo $message
What can I say? A command prompt with no power? Amazingly some people have twisted it to achieve amazing things. I still hate it though and wish Microsoft would provide a really useful batch language for Windows/NT (and shipping Perl in the Resource Kit doesn't count guys!).
SET MSG="Hello World" ECHO %MSG%
Experimental here means that I have experimented with these languages. It does not mean that they are some kind of computer science experiment. Rather I have used these languages to write some kind of minimalist application, but only for the purpose of educating myself about the language. The dividing line between some of these and the little languages above is fine, but ultimately the little languages have produced tools which I use in earnest, the experimental ones produced tools which I do not use on a regular basis.
This is not to denigrate these languages in any way - they are all production languages to someone else and I have learned valuable lessons about programming from all of them. I heartily recommend to any wannabe programmer that he/she experience as many different styles of programming as possible - and these languages all offer something different from the more mainstream languages above.
BASIC was technically my first programming language. But what I did with it was so trivial that I don't really consider it programming. I really started using BASIC on my CP/M Microcomputer and it introduced me to Random Access files. I still occasionally play with BASIC - especially if I'm working on a PC and its the only programming tool around!
Visual Basic aficionados keep trying to persuade me that the modern dialects of the language are of good quality, but despite downloading the free CCE edition and creating a few simple apps, I just cannot work up any real enthusiasm. Sorry BASIC.
LET MSG$ = "Hello World" PRINT MSG$;
Lisp is described by its fans as 'the only beautiful programming language'. Its detractors say Lisp stands for 'Lots of Irrelevant Silly Parentheses'. I sympathize with both views. Lisp really stands for List Processing and is very descriptive of how the language both looks and works. Everything in Lisp is either a list or an atom - an atom is an element of a list which is not itself a list.
It is this fundamental cleanness of form and its simple syntax which provokes the 'beautiful language' reaction above. What I learned from Lisp is a different way to structure problems, use of recursion (something I had previously avoided as too complicated) and an appreciation of the notion that data can be a program and vice versa.
The other notable thing about Lisp is that it is one of the very earliest Computer Languages along with COBOL and Fortran. I find it interesting that these earliest languages are still each going strong in their respective fields while more modern languages (Algol, PL/1, CORAL, even ADA) have bloomed then faded from sight. Maybe the designers of those early languages knew some things that have been lost to later designers?
Finally Lisp has a number of variants. The versions I have used most are Elisp: the macro language of the Emacs editor, XLISP an experimental OO version and Flavors, a very early experimental OO dialect. Mainstream Lisp has acquired a standard: Common Lisp and an OO system: CLOS. CLOS is perhaps the most complete OO environment available today, albeit a fairly verbose and extremely complex one. For that reason I won't even attempt to do an OO Hello world.
( (setq msg "Hello World") (print 'msg))
I first came across Logo on my CP/M micro. It was a strange inclusion in the software bundle: a simple programming language designed to teach children about computing using a set of commands for guiding a robot 'turtle' about the floor with a pen tracing the shapes. This became known as turtle graphics and has been ported to many other languages, including Pascal and Smalltalk.
Logo also had a serious side however and incorporated full List Processing capability and possesses many of the features of Lisp, including the concept of programs being lists in and of themselves. This makes Logo suitable for teaching (and implementing) Artificial Intelligence techniques but without the mass of parentheses and unusual syntax (from a procedural programmers viewpoint) inherent in Lisp.
More modern Logo's have OO capability and there are even versions for programming windows - complete with GUI class libraries.
To Hello
MAKE "Message [Hello World]
PRINT :Message
End
Hello
Prolog is different. Very different!
In Prolog you define rules of what you want to happen and leave the system to figure out how the system should do it. This is very intuitive to beginners, and very strange to programmers trained in just about any other language.
It is a mainstay of artificial intelligence research, especially in Europe and Japan. Indeed the Japanese, in an attempt to compete with the USA in computing announced in the mid '80s that they would produce a "Fifth Generation" computer based on Prolog by 1990. Such a machine never appeared but the Japanese did succeed in dominating computing by the much simpler strategy of building more and better memory chips than anyone else!
I played with Prolog because it was available on the VAX computer I used in my first job - I often wondered why? We certainly never used it in any kind of production capacity.
I've never really written any serious code in Prolog but the whole concept fascinates me. Maybe someday I'll find a real use for it, until then I'll keep playing when the mood takes me.
Message is "Hello World" Message?
Smalltalk is Objects. Everywhere. Always.
Although Simula 67 is generally held to be the first OO language, Smalltalk was the one that really got the ball going in the wider world. During the 1970's Smalltalk evolved into what was to be the definitive OO environment: Smalltalk 80.
If you want to sample Smalltalk 80 download a copy of Squeak from Disney.com. The environment is a faithful copy of the Smalltalk 80 programming environment, including the GUI which is distinctly eccentric by modern standards but was the catalyst for the Mac and windows etc.
My preferred Smalltalk implementation is Dolphin Smalltalk for Win95. This is unusual in that the development environment is free but if you want to distribute programs as EXEs then you need to buy a deployment kit. This seems to be a reasonable alternative to shareware as a try-before-you-buy scheme.
The environment is good and the HTML format documentation and tutorial is very readable. There is a support forum too.
Smalltalk fans love the consistency of the language (as I said, everything is an object) and its small set of syntactic constructs - making it easy to learn. At least thats the idea - it took me 3 attempts with 2 different environments to get my head around it. At times Smalltalk rivals C and Perl in the use of obscure and overloaded symbols (@,#,[,], etc).
message := string new: "Hello World". message print.
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