HLS(ID:4360/hls001)

hierarchical language system 

for Hierarchical Language System

Nobuyoshi Terashima NTT 1976

Hybrid structured and extensible programming language, comprised of two parts (SPL and EPL)
Related languages
SIMPL-T => HLS   Influence
SPIL => HLS   Influence
HLS => EPL   Subsystem
HLS => SPL   Subsystem
References:
  • Terashima, Nobuyoshi "The Hierarchical Language System" view details Abstract: The Hierarchical Language System HLS is presented. HLS consists of the structured programming language SPL and the extensible programming language EPL which is built upon SPL layer and provides statement and expression extention facilities, and provides to automate top down programming as much as possible by the following means.
    (1)  To describe each breakdown process in the programming languages EPL and SPL, in order to eliminate ambiguity of each breakdown representations which are in general written in natural languages.
    (2)  To generate the whole system which runs in the actual programming environment by this system.
    This paper describes HLS concepts and language specifications of
    its components.
    HLS effectiveness is to be presented in the near future.
    Extract: Analysis
    It is assumed that software systems be classified inco the following fields; operating systems, compilers, utilities and application programs. In each field, there are many routines, which are characteristic of the field and occur in the field frequently. When using PL/I, COBOL or an assembler language to write those routines, they are described as macros or (function) subroutines, and invoked by means of «acro or subroutine references when necessary for processing.
    This invocation method cannot contribute to enhancement of programming readability and descriptive convenience.
    Therefore, it is necessary that readability and descriptive convenience should be enhanced by providing a descriptive means fitted for the field, because it is expected that readability and descriptive convenience might contribute to enhancement of programming reliability and productivity as well as program maintenance.
    The following implementations are enumerated to satisfy toe above requirement:
    (1)  To develop a new language fitted for a particular field.
    (2)  To make use of extensible programming language concepts. The foraer imple»entatior requires development of a new compiler language for each field.  Therefore, in setting up and maintenance the compiler language, a very large cost is involved. Therefore, in this research, the latter implementation is taken into consideration.

    Generally speaking, an extensible programming language has a base language besides extensi(1)  Programming reliability and productivity as well as program maintenance can be enhanced by SPL. Effectivity can be enhanced by EPL. Effectivity might be one of the major contributing factors for enhancement of programming reliability and productivity as well as program maintenance.
    (2)  HLS can provide a means by which representations, which are written in EPL and suitable to a particular field, are broken down into representations, which are written in SPL and transparent to the field, in a top down manner,.
    This paper describes HLS concepts, language specifications of HLS components.
    Especially, SPL and EPL language specifications are described in detail, because they are new programming languages proposed in this paper.
          in SIGPLAN Notices 12(07) July 1977 view details