Algol 68 (thing)

Algol 68 was ahead of its time, and contained many features that are considered state-of-the-art in modern languages. As Bjarne Stroustrup explains in his book The Design and Evolution of C++, Algol 68 had a significant influence on many features and the syntax/semantics of C++. For instance, the sucess of operator overloading in Algol 68 persuaded Stroustrup to persevere with it in C++.

Features of Algol 68:

• A general purpose language with a clean, consistant and unambiguous syntax.
• A fully-checked type-system with structures, unions, pointers, arrays and procedures.
• User-defined operators and operator overloading.
• Typed memory allocation with transparent garbage collection.
• Unions inherently know their current type.
• Dynamic sized arrays know their current bounds.
• Good string handling via flexible arrays of characters.
• Array and structure displays can be used in any context.
• Advanced handling of arrays of any rank such as slicing.
• Complex arithmetic.
• Clear distinction between value semantics and reference semantics.
• No distinction between compile-time constants and run-time values.
• Modular programming with information hiding and type checking.