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Show 89 !he ability to incrementally develop and test a system, which· is inherent 1n all LISP systems, turned out to be perhaps the most significant element in the development of this system. !he ability to immediately explore alternate avenues for a certain operation without recompilation of the entire system allowed a truly modular development not possible under any other environment. The importance of running both interpreted and compiled code cannot be overlooked. PSL has, like many LISP systems, an impressive set of modules implementing general functions which can be used for operating on lists and vectors. The fact. that this library of user functions can Ce dynamically growing allows all users of the programming environment to contrioute to the research progress of the others. The simulator and the compiler make extensive use of the record constructing package (D EF STRUC T ) , the general sorting package (GSORT ) , the text editor (EMODE) , the parser generator (MINI), as well as s tandard packages such as the compiler, debugger, tracer, and prettyprinter. The ability to use packages as they become defined, without recompiling the entire system, is perhaps one of the most significant features of after the beginning of the work done. Its use in generating data any LIS? system. For example, DEFSTRUCT came along significantly structures and data accessors from which to simulate and compile made the addition of fi.elds in the state-machine database an almost trivial part of the system implementation. |
