Chapter 2 Programming Language Concepts R Sebesta

Nama: Stefanus Eduard Adrian

NIM: 1801382963

Kali ini saya akan menjawab Assignment #2 dari Chapter 2 Programming Language Concepts R Sebesta

Review Questions

6. What hardware capability that first appeared in the IBM 704 computer strongly affected the evolution of programming languages ? Explain why.

*Hardware capability that strongly affected the evolution of programming languages is the capability of both indexing and floating-point instructions in hardware. Because the floating-point  operations didn’t have to be simulated in software anymore, and that can save time for processing.

7. In what year was the Fortran design project begun ?

*The Fortran design project was begun in 1954.

8. What was the primary application area of computers at the time Fortran was designed ?

*Mathematics application area was the primary application area of computers at the time Fortarn was designed

9. What was the source of all of the control flow statements of Fortran I ?

*The control flow statements of Fortran I were based on 704 instructions. Although it is not clear whether the 704 designers dictated the control statement design of Fortran I or whether the designers of Fortran I suggested these instructions to the 704 designers.

10. What was the most significant feature added to Fortran I to get Fortran II ?

*The most significant feature added to Fortran I to get Fortran II was the independent compilation of subroutines. Without independent compilation, any change in a program required that the entire program be recompiled.

Problem Set

6. Make an educated guess as to the most common syntax error in LISP programs.

*The most common syntax error in LISP programs is probably the placement and number of parentheses. We can place parentheses wrongly in our programs if we are not careful. We can also has too many or too little parentheses if we are not careful. The use of parentheses is very important in LISP programs because parentheses is used pretty much in LISP programming.

7. LISP began as a pure functional language but gradually acquired more and more imperative features. Why ?

*Originally, John McCarthy intended to develop LISP to meet the demand for artificial intelligence as a functional programming language. But, most programming has been done in the imperative style, so we have many good imperative algorithms. And, in order to build efficient code, different LISP implementations provided more and more imperative fetures.

8. Describe in detail the three most important reasons, in your opinion, why ALGOL 60 did not become a very widely used language.
*The three most important reasons in my opinion: 

-Some of the features of ALGOL 60 were too flexible, they made understanding difficult and implementation inefficient. The best example of this is the pass-by-name method of passing parameters to subprograms.
-ALGOL 60 lacks of input and output statement. It was another major reason for its lack of acceptance. Implementation-dependent input/output made programs difficult to port to other computers.
-One of the most vital reason why ALGOL 60 didn’t become a very widely used language is because the entrenchment of Fortran among users and the lack of support by IBM. They were probably the most important factors in ALGOL 60’s failure to gain widespread use.

9. Why, in your opinion, did COBOL allow long identifiers when Fortran and ALGOL did not ?
*COBOL allowed long identifiers because COBOL was more of a reporting language than Fortran and ALGOL. COBOL used long identifiers because it made it easier to read the programs. If the programs used standard mathematical notation, it would be harder to read te programs. Also, Fortran was also a much older language that was built during a time of very little memory leaving little room for long identifiers.

10. Outline the major motivation of IBM in developing PL/I.

*By the early 1960s, the users of computers in industry had settled into two separate and quite different camps: scientific and business. From the IBM point of view, scientific programmers used programming language that had power in floating-point data and arrays. For business applications, people used programs that had power in decimal and character string data types, as well as elaborate and efficient input and output facilities. These perceptions naturally led to the concept of designing a single universal computer that would be capable of doing both floating-point and decimal arithmetic, and therefore both scientific and business applications. So, that motivated IBM to develop PL/I.