OPAL (OPtimized Applicative Language) is a functional programming language first developed at Technische Universität Berlin.
There is a later framework for static code analysis also called Opal.
Example program This is an example OPAL program, which calculates the GCD recursively.
Signature file (declaration) SIGNATURE GCD FUN GCD: nat ** nat -> nat
Implementation file (definition) IMPLEMENTATION GCD IMPORT Nat COMPLETELY DEF GCD(a,b) == IF a % b = 0 THEN b ELSE IF a-b < b THEN GCD(b,a-b) ELSE GCD(a-b,b) FI FI
References
External links The OPAL Home Page, archived, last modified 30 September 2010. OPAL Installation Guide, archived.
