CHAPTER 2

Nama : Aditya Isnugraha
Class   : LM01
NIM    : 1801419606

Assignment from Tri Djoko Wahjono
CHAPTER 2

- REVIEW QUESTION

11. What control flow statements were added to Fortran IV to get Fortran
      77?
      Answer : Character string handling, logical loop control statement and an if without an optional                           else clause were added to Fortran IV to get Fortran 77.


12. Which version of Fortran was the first to have any sort of dynamic
      variables?
      Answer : Fortran 90 is the first version of Fortran which support dynamic variables.


13. Which version of Fortran was the first to have character string handling?
      Answer : The first version of Fortran supporting character string handling is Fortran 77.


14. Why are linguists interested in artificial intelligence in the late 1950s?
      Answer : Because they were concerned with natural language processing, when in 1950’s, there                         are only computers with computation based on numeric data in arrays.


15. Where was LISP developed? By whom?
      Answer : It 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?
      Answer : 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.
      Answer : 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?
      Answer :
                    -   PL/I included the best of ALGOL 60 (recursion and block structure), FORTRAN                                  IV (separate compilation with communication through global data), and COBOL                                  (data structures, input/output, and report generating facilities), along with a few                                    new constructs

                    -   PL/I was the first language to have programs allowed to create concurrently executing                         tasks, the possibility to detect and handle 23 different types of exceptions, procedures                           allowed to be use recursively, pointers included as a data type, and reference to the                               cross sections of arrays

14. What are the arguments both for and against the idea of a typeless language?
      Answer : 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?
      Answer : Yes there are some non procedural languages other than Prolog, for example, Visual                             Basic, SQL.
                      -FORTRAN
                      -LISP
                      -ALGOL 60