Aldor

Aldor

Paradigm	Multi-paradigm: object-oriented, functional, imperative, dependent typed, logic
Designed by	Richard Dimick Jenks, Barry Trager, Stephen Watt, James Davenport, Robert Sutor, Scott Morrison
Developer	Thomas J. Watson Research Center
First appeared	1990 (1990)
Stable release	1.0.3
Preview release	1.1.0
Platform	Axiom computer algebra system
OS	Linux, Solaris, Windows
License	Aldor Public 2.0, Apache 2.0
Filename extensions	.al, .as
Website	www.aldor.org
Major implementations
Axiom computer algebra system
Influenced by
A#, Pascal, Haskell

Aldor is a programming language. It is the successor of A# as the extension language of the Axiom computer algebra system.

Aldor combines imperative, functional, and object-oriented features. It has an elaborate type system, allowing types to be used as first-class values. Aldor's syntax is heavily influenced by Pascal, but it is optionally indentation-sensitive, using whitespace characters and the off-side rule, like Python. In its current implementation, it is compiled, but an interactive listener is provided.

Aldor is distributed as free and open-source software, under the Apache License 2.0.

Examples

The Hello world program looks like this:

#include "aldor"
#include "aldorio"

stdout << "Hello, world!" << newline;

Example of dependent types (from the User Guide):

#include "aldor"
#include "aldorio"
#pile

sumlist(R: ArithmeticType, l: List R): R == 
    s: R := 0;
    for x in l repeat s := s + x
    s

import from List Integer, Integer, List SingleFloat, SingleFloat
stdout << sumlist(Integer, [2,3,4,5]) << newline
stdout << sumlist(SingleFloat, [2.0, 2.1, 2.2, 2.4]) << newline

99 Bottles of Beer:

#include "aldor"
#include "aldorio"

import from Integer, String;

bob(n: Integer): String == {
    b: String := " bottle";

    if n ~= 1 then b := b + "s";
    b + " of beer";
}

main(): () == {
    n: Integer := 99;
    otw: String := " on the wall";

    -- refrain
    while n > 0 repeat {
        stdout << n << bob(n) << otw << ", " << n << bob(n) << "." << newline;
        stdout << "Take one down and pass it around, ";
        n := n - 1;
        if n > 0 then stdout << n;
        else stdout << "no more";
        stdout << bob(n) << otw << "." << newline;
        stdout << newline;
    }

    -- last verse
    stdout << "No more" << bob(n) << otw << ", no more" << bob(n) << "." << newline;
    stdout << "Go to the store and buy some more, ";
    n: Integer := 99;
    stdout << n << bob(n) << otw << "." << newline;
}

main();

External links

• Official website
• Open Source Development - Git repository
• Aldor User Guide