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(); References External links Open Source Development - Git repository Aldor User Guide Experimental programming languages Object-oriented programming languages