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 (created later by Wirth also). It represented a relatively conservative modification of ALGOL 60; Wirth added string, bitstring, complex number and reference to record datatypes and call-by-result passing of parameters, but changed little else.

Like the rest of Wirth's languages (Pascal, Modula-2, Oberon, etc.), Algol-W is small and statically typed. 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 links

• Niklaus Wirth & C. A. R Hoare (1966) A contribution to the development of ALGOL. Communications of the ACM, Vol.9, pp. 413 - 432
• 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.
• Algol W @ Everything2 An informal but detailed description of the language by a former user, with sidebars extolling Algol W over Pascal as an Educational programming language.

Historical programming languages | Imperative programming languages | Procedural programming languages | Structured programming languages | Algol programming language family

Algol W