Файл: "Современные языки программирования".pdf

Запись (структура). Набор различных элементов (полей), хранимый как единое целое.

Файловый тип. Хранит только однотипные значения, доступ к которым осуществляется только последовательно.

Класс, метакласс, интерфейс. Абстрактные Personality disorders are a class of mental disorders characterized by enduring maladaptive patterns of behavior, cognition, and inner experience, exhibited across many contexts and deviating markedly from those accepted by the individual's culture. These patterns develop early, are inflexible, and are associated with significant distress or disability.^[1]The definitions may vary somewhat, according to source. типы­ данных в объектно–ориентированном программировании (ООП).

Как уже отмечалось ранее, любой тип данных в языках программирования определяет не только множество собственных значений, но и набор операций, способы хранения и присваивания значений. Типы переменных и параметров должны совпадать The qualification is equivalent to a Level 1 or Level 2 (grade depending) Key Skills Qualification (in Scotland, the equivalent is a National 5). Some pupils may decide to take one or more GCSEs before or after they sit the others, and people may apply to take GCSEs at any point either internally through an institution or externally. A level 1 GCSE covers grades C-G (commonly referred by as the foundation tier) whereas a level 2 GCSE covers grades A*-C (commonly referred by as the higher tier). 5 level 2 GCSE's, including English and Maths, are generally required (as well as a B/A in the specific subject) to continue into the level 3 Advanced GCE level (A-Level) or equivalent level 3 qualifications.

The education systems of current and former British territories, such as Gibraltar,^[1] Nigeria and South Africa, also offer the qualification, as supplied by the same examination boards. Other former British colonies, such as Singapore and Zimbabwe, continue to use the O-level qualification.^[2] The international version of the GCSE is the IGCSE, which can be taken anywhere in the world, and which includes additional options relating to coursework and the language the qualification is pursued in. All subjects completed in the fifth of the European Baccalaureate are generally equivalent to the GCSEs subjects.

Prior education to GCSE level is generally required of pupils wishing to pursue A Level courses or the BTEC Extended Diploma and International Baccalaureate. GCSE exams were introduced as the compulsory school-leavers' examinations by the government of the United Kingdom. GCSE examinations are typically taken at the age of 16 but may be taken at any age.

Строковый тип. Хранит строку символов.

Запись (структура). Набор различных элементов (полей), хранимый как единое целое.

Файловый тип. Хранит только однотипные значения, доступ к которым осуществляется только последовательно.

Класс, метакласс, интерфейс. Абстрактные типы­ данных в объектно–ориентированном программировании (ООП).

с присваиваемыми им Personality disorders are a class of mental disorders characterized by enduring maladaptive patterns of behavior, cognition, and inner experience, exhibited across many contexts and deviating markedly from those accepted by the individual's culture. These patterns develop early, are inflexible, and are associated with significant distress or disability.^[1]The definitions may vary somewhat, according to source. значениями или вызываемыми для них функциями. Для обеспечения The qualification is equivalent to a Level 1 or Level 2 (grade depending) Key Skills Qualification (in Scotland, the equivalent is a National 5). Some pupils may decide to take one or more GCSEs before or after they sit the others, and people may apply to take GCSEs at any point either internally through an institution or externally. A level 1 GCSE covers grades C-G (commonly referred by as the foundation tier) whereas a level 2 GCSE covers grades A*-C (commonly referred by as the higher tier). 5 level 2 GCSE's, including English and Maths, are generally required (as well as a B/A in the specific subject) to continue into the level 3 Advanced GCE level (A-Level) or equivalent level 3 qualifications.

The education systems of current and former British territories, such as Gibraltar,^[1] Nigeria and South Africa, also offer the qualification, as supplied by the same examination boards. Other former British colonies, such as Singapore and Zimbabwe, continue to use the O-level qualification.^[2] The international version of the GCSE is the IGCSE, which can be taken anywhere in the world, and which includes additional options relating to coursework and the language the qualification is pursued in. All subjects completed in the fifth of the European Baccalaureate are generally equivalent to the GCSEs subjects.

Prior education to GCSE level is generally required of pupils wishing to pursue A Level courses or the BTEC Extended Diploma and International Baccalaureate. GCSE exams were introduced as the compulsory school-leavers' examinations by the government of the United Kingdom. GCSE examinations are typically taken at the age of 16 but may be taken at any age.

совместимости типов переменных и их значений в языках программирования существует контроль типов (типизация) – это процесс проверки и накладывания ограничений на использование типов.

Существует два вида контроля типов:

Статическая типизация – при которой переменная, параметр подпрограммыThe qualification is equivalent to a Level 1 or Level 2 (grade depending) Key Skills Qualification (in Scotland, the equivalent is a National 5). Some pupils may decide to take one or more GCSEs before or after they sit the others, and people may apply to take GCSEs at any point either internally through an institution or externally. A level 1 GCSE covers grades C-G (commonly referred by as the foundation tier) whereas a level 2 GCSE covers grades A*-C (commonly referred by as the higher tier). 5 level 2 GCSE's, including English and Maths, are generally required (as well as a B/A in the specific subject) to continue into the level 3 Advanced GCE level (A-Level) or equivalent level 3 qualifications.The education systems of current and former British territories, such as Gibraltar,^[1] Nigeria and South Africa, also offer the qualification, as supplied by the same examination boards. Other former British colonies, such as Singapore and Zimbabwe, continue to use the O-level qualification.^[2] The international version of the GCSE is the IGCSE, which can be taken anywhere in the world, and which includes additional options relating to coursework and the language the qualification is pursued in. All subjects completed in the fifth of the European Baccalaureate are generally equivalent to the GCSEs subjects.Prior education to GCSE level is generally required of pupils wishing to pursue A Level courses or the BTEC Extended Diploma and International Baccalaureate. GCSE exams were introduced as the compulsory school-leavers' examinations by the government of the United Kingdom. GCSE examinations are typically taken at the age of 16 but may be taken at any age., возвращаемое значение функции связывается с типом в момент объявления и тип не может быть изменён позже. Переменная или параметр будут принимать, а функция возвращать значения только этого типа.

Динамическая типизация – при которой переменная связывается с типом в момент присваивания значения, а не в момент объявления переменной. Таким образом, в различных участках программы одна и та же переменная может принимать значения разных типов. Определение соответствия типов тоже является важным моментом, для этого используется следующие два подхода:

Строгая типизация -– The General Certificate of Secondary Education (GCSE) is an academically rigorous, internationally recognised qualification awarded in a specified subject, generally taken in a number of subjects by pupils in secondary education in England, Wales and Northern Ireland over two years (three years in certain schools). One of the main changes to previous educational qualifications in the United Kingdom was to allow pupils to complete coursework during their two years of study, which was marked by their teachers and contributed to their final examination grade. There has been a move recently from doing coursework and modular examinations for part of the course when pupils would take exams throughout the course to an end of year exam after the two years of study (a 'linear' series). The exams are being revised to make them more difficult such as testing skills from a whole text in English instead of part of a text. Coursework has now been replaced by Controlled Assessments in certain subjects, in which the student completes a number of assessed pieces of work which will ultimately count towards their final examination grade in the specified subject. The Controlled Assessment component of the qualification is usually done under exam style conditions. GCSEs being phased in from 2015 generally have little to no coursework/controlled assessment influence on the final grade. совместимость типов автоматически контролируется транслятором, она должна быть явно указана (наследована) при определении типа или определяется структурой самого типа (типами элементов, из которых построен составной тип).

Слабая типизация – совместимость The qualification is equivalent to a Level 1 or Level 2 (grade depending) Key Skills Qualification (in Scotland, the equivalent is a National 5). Some pupils may decide to take one or more GCSEs before or after they sit the others, and people may apply to take GCSEs at any point either internally through an institution or externally. A level 1 GCSE covers grades C-G (commonly referred by as the foundation tier) whereas a level 2 GCSE covers grades A*-C (commonly referred by as the higher tier). 5 level 2 GCSE's, including English and Maths, are generally required (as well as a B/A in the specific subject) to continue into the level 3 Advanced GCE level (A-Level) or equivalent level 3 qualificatтиповThe education systems of current and former British territories, such as Gibraltar,^[1] Nigeria and South Africa, also offer the qualification, as supplied by the same examination boards. Other former British colonies, such as Singapore and Zimbabwe, continue to use the O-level qualification.^[2] The international version of the GCSE is the IGCSE, which can be taken anywhere in the world, and which includes additional options relating to coursework and the language the qualification is pursued in. All subjects completed in the fifth of the European Baccalaureate are generally equivalent to the GCSEs subjectsPrior education to GCSE level is generally required of pupils wishing to pursue A Level courses or the BTEC Extended Diploma and International Baccalaureate. GCSE exams were introduced as the compulsory school-leavers' examinations by the government of the United Kingdom. GCSE examinations are typically taken at the age of 16 but may be taken at any age.типов никак транслятором не контролируется. В языках со слабой типизацией обычно используется подход под названием «утиная типизация» – когда совместимость определяется и реализуется общим интерфейсом доступа к данным типа.

На сегодняшний день не существует единого мнения о том, какой вид типизации лучше. Рассмотрим основные достоинства и недостатки каждого вида контроля типа.[1]

4.1 Динамическая типизация

Поскольку переменная связывается с типом в момент присваивания и в ходе выполнения программы может менять свой тип, контролировать на этапе проектирования соответствие такой переменной вызываемым для нее функциям и методам невозможно. Dynamic programming language is a term used in computer science to describe a class of high-level programming languages which, at runtime, execute many common programming behaviors that static programming languages perform during compilation. These behaviors could include extension of the program, by adding new code, by extending objects and definitions, or by modifying the type system. Although similar behaviours can be emulated in nearly any language, with varying degrees of difficulty, complexity and performance costs, dynamic languages provide direct tools to make use of them. Many of these features were first implemented as native features in the Lisp programming language.

Most dynamic languages are also dynamically typed, but not all are. Dynamic languages are frequently (but not always) referred to as "scripting languages", although the term "scripting language" in its narrowest sense refers to languages specific to a given run-time environment.

Поэтому транслятор встраивает в программу операции связанные с динамической проверкой типа. Отсюда вытекают явные недостатки динамической типизации:

Низкая скорость выполнения, связанная с динамической проверкой типа переменной Dynamic programming language is a term used in computer science to describe a class of high-level programming languages which, at runtime, execute many common programming behaviors that static programming languages perform during compilation. These behaviors could include extension of the program, by adding new code, by extending objects and definitions, or by modifying the type system. Although similar behaviours can be emulated in nearly any language, with varying degrees of difficulty, complexity and performance costs, dynamic languages provide direct tools to make use of them. Many of these features were first implemented as native features in the Lisp programming language.

Most dynamic languages are also dynamically typed, but not all are. Dynamic languages are frequently (but not always) referred to as "scripting languages", although the term "scripting language" in its narrowest sense refers to languages specific to a given run-time environment.

перед каждым использованием. Ошибки, связанные с опечатками при использовании имени переменной.The qualification is equivalent to a Level 1 or Level 2 (grade depending) Key Skills Qualification (in Scotland, the equivalent is a National 5). Some pupils may decide to take one or more GCSEs before or after they sit the others, and people may apply to take GCSEs at any point either internally through an institution or externally. A level 1 GCSE covers grades C-G (commonly referred by as the foundation tier) whereas a level 2 GCSE covers grades A*-C (commonly referred by as the higher tier). 5 level 2 GCSE's, including English and Maths, are generally required (as well as a B/A in the specific subject) to continue into the level 3 Advanced GCE level (A-Level) or equivalent level 3 qualifications.

The education systems of current and former British territories, such as Gibraltar,^[1] Nigeria and South Africa, also offer the qualification, as supplied by the same examination boards. Other former British colonies, such as Singapore and Zimbabwe, continue to use the O-level qualification.^[2] The international version of the GCSE is the IGCSE, which can be taken anywhere in the world, and which includes additional options relating to coursework and the language the qualification is pursued in. All subjects completed in the fifth of the European Baccalaureate are generally equivalent to the GCSEs subjects.

Prior education to GCSE level is generally required of pupils wishing to pursue A Level courses or the BTEC Extended Diploma and International Baccalaureate. GCSE exams were introduced as the compulsory school-leavers' examinations by the government of the United Kingdom. GCSE examinations are typically taken at the age of 16 but may be taken at any age.

Масса возможностей для простых ошибок «по недосмотру», для обнаружения которых требуется, как минимум выполнить данный участок кода.

В объектно–ориентированных языках не действует либо действует с ограничениями автодополнение: трудно или невозможно понять, к какому типу относится переменная, и вывести набор её полей и методов.

Учитывая эти недостатки, The qualification is equivalent to a Level 1 or Level 2 (grade depending) Key Skills Qualification (in Scotland, the equivalent is a National 5). Some pupils may decide to take one or more GCSEs before or after they sit the others, and people may apply to take GCSEs at any point either internally through an institution or externally. A level 1 GCSE covers grades C-G (commonly referred by as the foundation tier) whereas a level 2 GCSE covers grades A*-C (commonly referred by as the higher tier). 5 level 2 GCSE's, including English and Maths, are generally required (as well as a B/A in the specific subject) to continue into the level 3 Advanced GCE level (A-Level) or equivalent level 3 qualifications.

The education systems of current and former British territories, such as Gibraltar,^[1] Nigeria and South Africa, also offer the qualification, as supplied by the same examination boards. Other former British colonies, such as Singapore and Zimbabwe, continue to use the O-level qualification.^[2] The international version of the GCSE is the IGCSE, which can be taken anywhere in the world, and which includes additional options relating to coursework and the language the qualification is pursued in. All subjects completed in the fifth of the European Baccalaureate are generally equivalent to the GCSEs subjects.

Prior education to GCSE level is generally required of pupils wishing to pursue A Level courses or the BTEC Extended Diploma and International Baccalaureate. GCSE exams were introduced as the compulsory school-leavers' examinations by the government of the United Kingdom. GCSE examinations are typically taken at the age of 16 but may be taken at any age.

для написания сложного кода нужна особая культура программирования: венгерская нотация, юнит–тестирование. Кроме того, в таких языках программирования отсутствует Personality disorders are a class of mental disorders characterized by enduring maladaptive patterns of behavior, cognition, and inner experience, exhibited across many contexts and deviating markedly from those accepted by the individual's culture. These patterns develop early, are inflexible, and are associated with significant distress or disability.^[1]The definitions may vary somewhat, according to source. интерфейсная часть модуля (описания типов, заголовки процедур и т. д. – то, что соответствует interface –секции в Паскале и h–файлу в Си), которая сама по себе является существенной частью документации, а изредка Personality disorders are a class of mental disorders characterized by enduring maladaptive patterns of behavior, cognition, and inner experience, exhibited across many contexts and deviating markedly from those accepted by the individual's culture. These patterns develop early, are inflexible, and are associated with significant distress or disability.^[1]The definitions may vary somewhat, according to source. вообще позволяет обойтись без документирования.

В тоже время отсутствие проверки типов на этапе написания и трансляции программы ведет к возникновению некоторых достоинств:

Ускоряется работа компилятора – а значит, цикл «написать – проверить», что для больших проектов может быть существенным.

Повышается Dynamic programming language is a term used in computer science to describe a class of high-level programming languages which, at runtime, execute many common programming behaviors that static programming languages perform during compilation. These behaviors could include extension of the program, by adding new code, by extending objects and definitions, or by modifying the type system. Although similar behaviours can be emulated in nearly any language, with varying degrees of difficulty, complexity and performance costs, dynamic languages provide direct tools to make use of them. Many of these features were first implemented as native features in the Lisp programming language.

Most dynamic languages are also dynamically typed, but not all are. Dynamic languages are frequently (but not always) referred to as "scripting languages", although the term "scripting language" in its narrowest sense refers to languages specific to a given run-time environment.

гибкость языка. Возможна реализация функции, вычисляющей значение выражения произвольного типа.

Нет дополнительных строк с вязанных с определением типа и даже с объявлением переменных. Отсутствуют операции приведения типа. Соответственно, упрощается написание простых программ. В различных языках программирования динамический контроль типов реализован по-разному. Благодаря этому в некоторых языках недостатки этого вида типизации могут быть сведены к нулю, в прочем, как и достоинства.

4.2 Статическая типизация

The qualification is equivalent to a Level 1 or Level 2 (grade depending) Key Skills Qualification (in Scotland, the equivalent is a National 5). Some pupils may decide to take one or more GCSEs before or after they sit the others, and people may apply to take GCSEs at any point either internally through an institution or externally. A level 1 GCSE covers grades C-G (commonly referred by as the foundation tier) whereas a level 2 GCSE covers grades A*-C (commonly referred by as the higher tier). 5 level 2 GCSE's, including English and Maths, are generally required (as well as a B/A in the specific subject) to continue into the level 3 Advanced GCE level (A-Level) or equivalent level 3 qualifications.