Clu

1 definition found

From The Free On-line Dictionary of Computing (27 SEP 03) [foldoc]:

  CLU
       
          CLUster.
       
          An {object-oriented} programming language developed at {MIT}
          by Liskov et al in 1974-1975.


       
          CLU is an {object-oriented} language of the {Pascal} family
          designed to support data abstraction, similar to {Alphard}.
          It introduced the {iterator}: a {coroutine} yielding the
          elements of a data object, to be used as the sequence of
          values in a 'for' loop.
       
          A CLU program consists of separately compilable procedures,
          {cluster}s and iterators, no nesting.  A cluster is a module
          naming an abstract type and its operations, its internal
          representation and implementation.  Clusters and iterators may
          be generic.  Supplying actual constant values for the
          parameters instantiates the {module}.
       
          There are no {implicit type conversion}s.  In a cluster, the
          explicit type conversions 'up' and 'down' change between the
          abstract type and the representation.  There is a universal
          type 'any', and a procedure force[] to check that an object is
          a certain type.  Objects may be mutable or {immutable}.
       
          {Exception}s are raised using 'signal' and handled with
          'except'.  {Assignment} is by sharing, similar to the sharing
          of data objects in {Lisp}.  Arguments are passed by
          {call-by-sharing}, similar to {call-by-value}, except that the
          arguments are objects and can be changed only if they are
          mutable.  CLU has {own variable}s and multiple assignment.
       
          See also {Kamin's interpreters}, {clu2c}.
       
          ["CLU Reference Manual", Barbara Liskov et al, LNCS 114,
          Springer 1981].
       
          E-mail: Paul R. Johnson .
       
          {Versions for Sun and VAX/VMS
          (ftp://pion.lcs.mit.edu/pub/clu/)}.  {Portable version
          (ftp://mintaka.lcs.mit.edu/pub/dcurtis/)}.
       
          (1994-12-16)