ALGOL W

Algol-W is a programming language. It was Niklaus Wirth s proposal for a successor to ALGOL 60 in the ALGOL 68 committee.

Algol-W is clearly a transitionary stage between ALGOL 60 and Pascal programming language (created later by Wirth also). It represented a relatively conservative modification of ALGOL 60; to ALGOL 60 Wirth added Character_string_(computer_science), bitstring, complex number and Reference_(computer_science) to Composite_type datatypes and a Parameter_(computer_science) but changed little else.

Like the rest of Wirth s languages (Pascal, Modula-2, Oberon programming language, etc.), Algol-W is small and static typing. The language that eventually became ALGOL 68 is much larger and more complex than Algol-W, and it differs more from Algol 60 than Algol-W does.

= Code Sample =

record PERSON ( string NAME; integer AGE; logical MALE; reference(PERSON) FATHER, MOTHER, YOUNGESTOFFSPRING, ELDERSIBLING ); reference(PERSON) procedure YOUNGESTUNCLE (reference(PERSON) R); begin reference(PERSON) P, M; P := YOUNGESTOFFSPRING(FATHER(FATHER(R))); while (P ¬= null) and (¬ MALE(P)) or (P = FATHER(R)) do P := ELDERSIBLING(P); M := YOUNGESTOFFSPRING(MOTHER(MOTHER(R))); while (M ¬= null) and (¬ MALE(M)) do M := ELDERSIBLING(M); if P = null then M else if M = null then P else if AGE(P) < AGE(M) then P else M end

= External References =

*[http://portal.acm.org/citation.cfmid=365696.365702 Niklaus Wirth & C. A. R Hoare (1966)] A contribution to the development of ALGOL. Communications of the ACM, Vol.9, pp. 413 - 432

*[http://www-db.stanford.edu/TR/CS-TR-68-89.html Stanford Computer Science Department Technical Report CS-TR-68-89] Various documents for Stanford University s 1972 implementation of Algol-W. The report includes the Algol W Language Description .