Influences on Language Design: Computer Architecture

Questions and Answers

What makes human readability in programming languages harder to define?

The lack of control statements in programming languages

The complexity of algorithms used in programming languages (correct)

The size of the programming language itself

The need for more abstractions in programming languages

What contributes to the readability of a programming language?

Control statements and simplicity only

Syntax and data types only

The number of lines of code in a program

Orthogonality, control statements, data types, syntax, and simplicity (correct)

Why are complex programming languages harder to learn?

They have too many abstractions

They have multiplicity, making it harder to understand the program's meaning (correct)

They have fewer control statements

They are less orthogonal

What is an example of multiplicity in programming languages?

Having different ways to accomplish the same operation Signup and view all the answers

What is orthogonality in programming languages?

The property of language constructs behaving the same in different contexts Signup and view all the answers

What is an example of nonorthogonality in programming languages?

In C/C++, arrays cannot be returned from a function Signup and view all the answers

What is the benefit of simplicity in programming languages?

It reduces the amount of detail, making changes in one part of the program have a limited effect on other parts Signup and view all the answers

What is the effect of overloading operators in programming languages?

It decreases the clarity of the program's meaning Signup and view all the answers

What is the purpose of the ADDL instruction in VAX Assembler?

To perform an arithmetic operation on two operands Signup and view all the answers

What was the most common control mechanism in programs in the 1950s and 1960s?

Goto statements Signup and view all the answers

What feature of modern programming languages enhances readability?

The ability to create custom data types Signup and view all the answers

What type of architecture has influenced the development of imperative languages?

Von Neumann architecture Signup and view all the answers

What is a disadvantage of using a large and diverse set of constructs in a programming language?

It makes the language easier to misuse Signup and view all the answers

Which programming methodology led to the development of languages with data abstraction?

Object-oriented programming Signup and view all the answers

What is the importance of writability in modern programming languages?

It is more important than efficiency Signup and view all the answers

What is the basic concept of imperative languages?

Machine state Signup and view all the answers

What is a key benefit of compile-time type checking in programming languages?

Improved program reliability Signup and view all the answers

Which language is well-suited for report generating?

COBOL Signup and view all the answers

Which of the following languages is NOT an imperative language?

ML Signup and view all the answers

What is the key question in functional programming languages?

What function must be applied to our initial machine and our data? Signup and view all the answers

What is the purpose of special words in programming languages?

To close structures such as endif and endwhile Signup and view all the answers

Why is it important to prevent dangling reference assignments in programming languages?

To prevent unexpected or disastrous behavior during execution Signup and view all the answers

What is an advantage of using records to store complex data objects?

It makes the code more readable Signup and view all the answers

What is a significant challenge in achieving reliability in programming languages?

Checking rules at translation or execution time Signup and view all the answers

Which programming paradigm focuses on the state changes as each statement is executed?

Imperative Signup and view all the answers

What is the form of statements in imperative languages?

statement1; statement2; … … Signup and view all the answers

What is an important aspect of reliability in programming languages?

Ability to catch runtime errors Signup and view all the answers

How many different programming language paradigms are there?

4 Signup and view all the answers

What is a potential issue with aliasing in programming languages?

Unnecessary errors Signup and view all the answers

What is a factor that affects the cost of program execution?

Computer speed Signup and view all the answers

What is a consideration in the cost of program translation?

Compiler optimization Signup and view all the answers

What is an aspect of the cost of program creation?

How quickly the program can be developed and executed correctly Signup and view all the answers

What is the purpose of the gcd method in the IntWithGcd class?

To find the greatest common divisor of two numbers Signup and view all the answers

What is the trade-off between reliability and cost of execution?

Reliability decreases with cost of execution Signup and view all the answers

What type of implementation method involves translating source code into machine code?

Compilation Signup and view all the answers

What is the purpose of an assembler in the compiling process?

To translate assembly code into machine code Signup and view all the answers

What is the output of the interpreter in the pure interpretation process?

Output Signup and view all the answers

What is the intermediate step in the hybrid interpretation process?

Intermediate code Signup and view all the answers

Study Notes

Readability

Harder to define human readability in precise terms
Requires a programming language to provide enough abstractions to make algorithms clear to someone unfamiliar with the program's details
In larger programs, readability requires reducing the amount of detail so that changes in one part have a limited effect on other parts

Characteristics of Readability

Simplicity: fewer basic components, less complexity, and reduced multiplicity (e.g., various ways to accomplish an operation)
Orthogonality: language constructs should not behave differently in different contexts
Control Statements: introduction of while, for, and if-then-else eliminated the need for gotos and led to more readable programs
Data Types and Structures: diverse set of data types and ability to create own data types increases readability
Syntax: features like identifier forms, special words, and form and meaning enhance readability

Writability

Historically, writability was less important than efficiency
With faster computers, writability has become more important
Writability must be considered within the context of the language's target problem domain
A large and diverse set of constructs is easier to misuse than a smaller set of constructs with consistent rules

Reliability

Assurance that a program will not behave in unexpected or disastrous ways during execution
Type Checking: a large factor in program reliability, with compile-time type checking being more desirable
Exception Handling: ability to catch run-time errors and make corrections can prevent reliability problems
Aliasing: having two or more ways of referencing the same data object can cause unnecessary errors

Cost of Use

Cost of program execution
Cost of program translation
Cost of program creation, testing, and use
Cost of program maintenance