Kapitel 6

Question 1

Assembly language

Answer 1

mnemonic systems that expresses machine code so that humans can easily understand it.

Question 2

Declarative paradigm

Answer 2

Asks a programmer to describe the problem to be solved rather than an algorithm to be followed. More precisely, a declarative programming system applies a pre-established general-purpose problem-solving algorithm to solve problems presented to it. In such an environment the task of a programmer becomes that of developing a precise statement of the problem rather than of describing an algorithm for solving the problem. Example language is Prolog. More on s.318.

Question 3

Fruitful function

Answer 3

a function that returns a value.

Question 4

Polymorphism

Answer 4

Something typical of object oriented programming, It is the concept of a customized interpretation of a message to a class. The message “draw yourself” is interpreted differently by a square than a circle for example.

Question 5

Actual parameters

Answer 5

the precise meanings assigned to these formal parameters when the function is applied.

Question 6

Assemblers

Answer 6

programs that convert mnemonic machine language into actual machine language.

Question 7

Ambiguous grammar

Answer 7

a grammar that allows two distinct parser trees for one string.

Question 8

Object-oriented paradigm

Answer 8

A software system is viewed as a collection of units called objects, each fo which is capable of performing the actions that are immediately related to itself as well as requesting actions of other objects. Together, these objects interact to solve the problem at hand.

Question 9

Encapsulation

Answer 9

Something typical of object oriented programming, it refers to restricting access to an objects internal properties. To say that certain features of an object are encapsulated means that only the object itself is able to access them.

Question 10

Freeformat languages

Answer 10

the positioning of the languages statements is not critical.

Question 11

How does a source program get translated to a object program?

Answer 11

The translation from a high-level language into a machine executable form is carried out in three steps:

1. Lexical analyze
2. Parser
3. Code generator
4. The lexical analyzer reads the source program symbol by symbol, identifying which groups of symbols represent tokens and classifying those tokens according to whether they are numeric value, words, arithmetic operators, and so on. The lexical analyzer encodes each token with its classification and hands them to the parser. During this process, the lexical analyzer skips over all comment statements.2. Thus the parser views the program in terms of lexical units (tokens) rather than individual symbols. It is the parser’s job to group these units into statements. Indeed, parsing is the process of identifying the grammatical structure of the program and recognizing the role of each component. The process of parsing a program is essentially that of constructing a parse tree for the cource program. Indeed, a parse tree represents the parser’s interpretation of the programs grammatical composition. For this reason the syntax rules describing a programs grammatical structure must not allow two distinct parse trees for one string, since this would lead to ambiguities within the parser.3. The code generation is the process of constructing the machine-language instructions to implement the statements recognized by the parser. —s. 300

Question 12

Natural and formal languages

Answer 12

formal languages are precisely defined by grammar whereas natural languages evolved over time without formal grammatical analysis.

Question 13

Lexical analysis

Answer 13

the process of recognizing which strings of symbols from the source program represent a single entity, or token.

Question 14

Third generation languages

Answer 14

Primitives of much higher level (in that they expressed instructions in larger increments) and machine independent (in that they did not rely on the characteristics of a particular machine). Examples are FORTRAN (Formula translator) which was developed for scientific and engineering applications, and COBOL (Common Business-oriented language) which was developed by the U.S. Navy for business applications.

Question 15

Parallell processing/concurrent processing

Answer 15

simultaneous execution of multiple activations.

Question 16

Fixed-format languages

Answer 16

Languages that insisted that each program statement be positioned in a particular manner on the printed page to simplify the parsing process.

Question 17

Variable

Answer 17

a location in main memory referenced to by a descriptive name.

Question 18

Formal Parameters

Answer 18

generic terms within functions (s. 294)

Question 19

Functional paradigm

Answer 19

Under this paradigm a program is viewed as an entity that accepts inputs and produces outputs. Mathematicians refer to such entities as functions, which is the reason this approach is called the functional paradigm. Under this paradigm a program is cinstructed bu connecting smaller predefined program units (predefined functions) so that each units outputs are used as another units inputs in such a way that the desired overall input-to-output relationship is obtained. In short, the programming process under the functional paradigm is that of building functions as nested complexes of simples functions.

Question 20

Imperative software development paradigm

Answer 20

also known as procedural paradigm, represents the traditional approach to the programming process. It is the paradigm on whish python and our pseudocode are based as well as the machine language discussed. The imperative paradigm defines the programming process to be the development of a sequence of commands that, when followed, manipulate data to produce the desired result. Thus the imperative paradigm tells us to approach the programming process by finding an algorithm to solve the problem at hand and then expressing that algorithm as a sequence of commands.