Chapter 1 - Introduction

Question 1

6 Reasons for studying concepts of PLs

Answer 1

1) increased capacity to express programming concepts
2) improved background for choosing appropriate languages
3) increased ability to learn new languages
4) Understanding the significance of implementation
5) increased ability to design new languages
6) overall advancement of computing

Question 2

Increased capacity to express programming concepts. Why important?

Answer 2

• awareness to a wider variety of PLs features allows programmers to more easily overcome the data/algorithmic limitations of any one language
• knowing more languages help broaden the scope SW dev thought process

Question 3

Why is the ability to choose the appropriate language important?

Answer 3

-allows the programmer to pick the best PL for the task at hand

Question 4

Why is it a important to understand the significance of implementation?

Answer 4

Allows for better understanding of how a PL is more or less efficient and suited for a particular task

Question 5

6 Programming Domains

Answer 5

Scientific applications 
Business applications 
AI
Systems Programming
Scripting Languages 
Special Purpose Langs

Question 6

5 Programming Lang Eval Criteria

Answer 6

1) Readability
2) Writability
3) Reliability
4) Cost
5) Others

Question 7

Readability factors

Answer 7

Overall simplicity
Breadth of features (too many or repeated features is bad)
Orthogonality
Construct meaning is context independent
Control Stmts
Data type and structures
Syntax

Question 8

Writability Factors

Answer 8

Simplicity and orthogonality support for abstraction

Expressivity

Question 9

Reliability Factors

Answer 9

Type checking
Exception handling
aliasing
Readability & Writability

Question 10

Cost Factors

Answer 10

Programmer training needed 
Software creation 
Compilation 
Execution
Compiler cost
Poor reliability maintenance

Question 11

Other Factors

Answer 11

Portability
Generality
Well-definedness

Question 12

2 influences of Lang design

Answer 12

Computer architecture

Programming methodologies

Question 13

Influence of Computer architecture on Lang design

Answer 13

The use of von Neumann machines contributes to use of imperative Langs

Question 14

Influence of programming methodologies on Lang design

Answer 14

50s and 60s ➡️ worried about efficiency

Late 60s ➡️ people efficiency aka readability

Late 70s ➡️ data abstraction

80s ➡️ object oriented programming

Question 15

Lang categories

Answer 15

Imperative
Functional
Logic
Object oriented

Question 16

Imperative Lang examples

Answer 16

C 
Fortran 
COBOL 
PL1
Algol

Question 17

Functional Lang examples

Answer 17

ML

LISP

Question 18

Logic Lang examples

Answer 18

Prolog

Question 19

3 Lang design trade offs

Answer 19

Reliability vs cost of execution
Writability vs readability
Flexibility vs safety

Question 20

3 Implementation Methods

Answer 20

Compilation
Pure interpretation
Hybrid systems

Question 21

What is compilation implementation?

Answer 21

Translates high level code to machine code

Question 22

The steps of compilation

Answer 22

Lexical analysis
Syntax analysis
Intermediate code generation
Code generation

Question 23

Pro and Con of Compilation

Answer 23

Pro ➡️ fast execution

Con ➡️ dedicated to a given hardware

Question 24

What is pure interpretation?

Answer 24

A program called an interpreter reads each statement of the program and executes it line by line

Question 25

Pro and Con of pure interpretation

Answer 25

Pro ➡️ error messages are close to source code

Con ➡️ slow execution

Question 26

What is a hybrid system

Answer 26

Translating high level code to an intermediate Lang that allows for easy interpretation

Question 27

Pros of hybrid system

Answer 27

Small translation cost

Medium execution speed

Question 28

What is a preprocessor?

Answer 28

A program that processes a source program immediately before Compilation