Assignment #2
pengajar : Tri Djoko Wahjono, Ir, M.Sc

Review Question :

11. What control flow statements were added to Fortran IV to get Fortran 
       77?
     =>Logical loop control statements.

12. Which version of Fortran was the first to have any sort of dynamic 
       variables?
    => Fortran 99

13. Which version of Fortran was the first to have character string handling?
    =>Fortran 77

14. Why were linguists interested in artificial intelligence in the late 1950s?
    => Linguists were concerned with natural language processing.

15. Where was LISP developed? By whom?
    =>LISP was developed at MIT by John McCarthy

Problem Set :

11. Was IBM’s assumption, on which it based its decision to develop PL/I,

      correct, given the history of computers and language developments since

      1964?

      =>The assumption is correct because in that 1970’s, PL/I is widely      
           used for both business and scientific applications although it suffers 
           a lot in previous years and afterwards.

12. Describe, in your own words, the concept of orthogonality in 
      programming language design.

      => It appears that orthogonality means the simplicity of programming 
           constructs, or a minimal number of control and data structures in a 
           language. Each additional construct increases the complexity,
           removing orthogonality.

13. What is the primary reason why PL/I became more widely used than

      ALGOL 68?

=> PL/I included the best of ALGOL 60 (recursion and block structure), FORTRAN IV (separate       compilation with communication through global data), and COBOL (data structure input/output, and report generating facilities), along with a few new constructs.

14. What are the arguments both for and against the idea of a typeless

      language?

      => Arguments for are obvious flexibility and ease of use. Without having to define a data type the    programmer is free to develop code that is generated quickly and without much thought. Learning the language is much simpler because one doesn’t have to determine size or how the compiler will interpret the type later on, only what information must be included. Arguments against include data insecurity, such as the assignment of a character type ‘A’ that could in fact be “defined” as a HEX value by the programmer. The compiler would also have trouble interpreting floating point values compared to integers. The resulting arithmetic would also cause serious problems; like adding 5 + “happy” and how they are interpreted  different than perhaps the programmer intended.

15. Are there any logic programming languages other than Prolog?

      =>-FORTRAN
      -LISP
      -ALGOL 60