[W/K] :: Ousterhout's dichotomy

  Ousterhout's dichotomy
       
           John Ousterhout's division of high-level
          languages into "system programming languages" and "scripting
          languages".  This distinction underlies the design of his
          language Tcl.
       
          System programming languages (or "applications languages") are
          strongly typed, allow arbitrarily complex data structures,
          and programs in them are compiled, and are meant to operate
          largely independently of other programs.  Prototypical system
          programming languages are C and Modula-2.
       
          By contrast, scripting languages (or "glue languages") are
          weakly typed or untyped, have little or no provision for
          complex data structures, and programs in them ("{scripts")
          are interpreted.  Scripts need to interact either with other
          programs (often as glue) or with a set of functions provided
          by the interpreter, as with the file system functions
          provided in a UNIX shell and with Tcl's GUI functions.
          Prototypical scripting languages are AppleScript, C Shell,
          MSDOS batch files, and Tcl.
       
          Many believe that this is a highly arbitrary dichotomy, and
          refer to it as "Ousterhout's fallacy" or "Ousterhout's false
          dichotomy".  While strong-versus-weak typing, data structure
          complexity, and independent versus stand-alone might be said
          to be unrelated features, the usual critique of Ousterhout's
          dichotomy is of its distinction of compilation versus
          interpretation, since neither semantics nor syntax depend
          significantly on whether code is compiled into
          machine-language, interpreted, tokenized, or
          byte-compiled at the start of each run, or any mixture of
          these.  Many languages fall between being interpreted or
          compiled (e.g. Lisp, Forth, UCSD Pascal, Perl, and
          Java).  This makes compilation versus interpretation a
          dubious parameter in a taxonomy of programming languages.
       
          (2002-05-28)