Navigation  without Java Scripts

Type Checking Detects Mistakes at Compile Time

Many Prologs are un-typed interpreters, but a distinguishing characteristic of PDC's version of Prolog is its type system that provides an extra level of security in programming. The type declarations document the code and allow the compiler to helpfully point out, at the early stages of development, common typing mistakes as well as more serious errors in logic. Moreover, by serving as a type of contract between programmer and development system, type declarations help ensure the integrity of a program over the entire product life cycle. Further, the declarations help the compiler to generate programs that are more efficient and save memory space during execution.

DOMAINS
  DETER = none ; deter(string)
  NOUNP = nounp(DETER,string,RELCL)
  RELCL = none ; relcl(string,VERBP)
  VP    = vp(string,string)
  NP    = np(string)
  SENTENCE = sent(NOUNP,VERBP) ;
             question(VP,NP)
  TOKL =string*
  VERBP = verb(string) ; verbp(string,NOUNP)

PREDICATES
  append(slist,slist,slist)
  fillbox(slist)
  tokl(string,TOKL)