Classification of High-Level Languages
High-level languages may be broadly classified as general-purpose or special-purpose. General-purpose languages are intended to be equally well suited to business, scientific, engineering or system software tasks. The most common general-purpose languages are Algol 68 and PL/1. Because of their broad capabilities, these languages are large and relatively difficult to use. The most common categories of special-purpose languages are commercial, scientific and educational. In the commercial field, Cobol still reigns supreme, while Fortran is still the most widely used scientific language. Basic is widely used in schools, with Logo and Prolog gaining popularity. Pascal is the most popular language at universities. Another way of classifying high level-languages is as procedural and declarative languages. Procedural languages state how a task is to be performed, often breaking programs into procedures, each of which specifies how a particular operation is to be performed. All the early high-level languages are procedural, with Algol, Pascal and Ada as typical examples. Declarative programming languages describe the data, structures and relationships between data relevant to a particular task, and specify what the objective of the task is. The process by which the task is to be carried out is not stated explicitly in the program. This process is determined by the language translation system. Prolog is an example of a declarative programming language.
Exercise 3. Translate the following word combinations. May be broadly classified, to be intended, to be well suited to, because of their broad capabilities, in the commercial field, to be widely used, the way of classifying, to break into procedures, to describe the data structures, relationships between data.
Exercise 4.. Write English equivalents to the following words and word combinations:
Exercise 5. Put questions to the underlined words. 1. General-purpose languages are intended to be equally well suited to business. 2. In the commercial field, Cobol still reigns supreme. 3. Pascal is the most popular language at universities. 4. Declarative programming languages describe the data structures.
Exercise 6. Rewrite the sentences in Reported Speech. 1. The teacher said to us: “Don’t write your lessons in pencil”. 2. He asked me: “Try to come in time”. 3. Mary asked: “Where does John live?” 4. Mr. Smith asked us: “Do you understand this exercise?” 5. Mary said: “I will be later.” 6. John asked: “Is it raining?”
Exercise 7. A. Paraphrase the sentences using the Objective Infinitive Complex. Model: I saw them. They came into the room. – I saw them come into the room. 1. He asked me about it. I heard it. 2. He went up to them and said something. I saw it. 3. I know that he is a very experienced teacher. 4. Nobody expected that she would marry again. 5. They will win the game. We are sure of it. 6. He’s a truthful boy. I know it.
B. Paraphrase the sentences using the Subjective Infinitive Complex. Model: People consider the problem to be very difficult. – The problem is considered to be very difficult. 1. It is said that this topic is very important. 2. They consider that this device is quite useful for their experiments. 3. It seems that she knows a lot about it. 4. I expect that he will solve the problem very quickly.
Exercise 8. Answer the questions to the text in writing. 1. What are two broad types of high-level languages? 2. What is the most common general-purpose language? 3. Why are high level-languages difficult to use? 4. Where is Basic widely used? 5. What is another way of classifying high-level languages? 6. What does procedural language state? 7. What do declarative programming languages describe and specify? 8. What is not stated explicitly in the program?
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