SLP(ID:5351/slp001)

simple list processing 

associative list processing language based on ASP-7
Related languages
ASP-7 => SLP   Based on
References:
  • Wiseman, N E "A simple list processing package for the PDP7" Second European Seminar of DECUS October 1966 view details
  • Gray, J. C. "Compound data structure for computer aided design" view details Extract: ASP structures
    An example of the use of a LISP-type list processor to build ring structures is the version of ASP written for the PDP-7 by Wiseman in his language SLP. 9 The calls to SLP procedures are low-level, (i.e., not based on recursive function theory); the lists are converted into rings by inserting a return pointer in the last CAR, the list itself terminating in the usual way on a NULL. An ASP element is created from a variable number of words arranged as a CDR chain, containing the ringstarts and ring ties. This terminates on a special ATOM, and is followed by a data chain. A feature of SLP is that the lists are hybrid in the sense that if possible, consecutive words in store are used, elimi- nating one or more CDR pointers. Deletion in ASP/ SLP is particularly simple, for if an element loses all references from other elements it becomes inaccessible, but is not immediately deleted; this is done later when the garbage collector sweeps through the store. ASP is lower-level than CORAL or APL in that the calls are to basic operations only, and such procedures such as Search and Find must be constructed by the user. On the other hand it is completely general as it stands, and will be used to implement investigations into a variety of data structure languages. One such is bassed on a possible equivalence between ASP structures and set theoretic operations.
          in Proceedings A.C.M. National Meeting, 1967 view details