Effective C# 50 Specific Way to Improve Your C# Item 50 Scott68.Chang

Agenda Item 50: Learn About the ECMA Standard Item 50: Learn About the ECMA Standard

Item 50: Learn About the ECMA Standard

European Computer Manufacturers Association (ECMA) The ECMA standard is the official word on how every feature in the C# language behaves. The ECMA standard is the official word on how every feature in the C# language behaves. – ECMA-334 defines the 1.0 standard for the C# language. – ECMA-335 defines the Common Language Runtime (CLR) and Common Language Infrastructure (CLI) standards.

Goals of C# C# is intended to be a simple, modern, general- purpose, object-oriented programming language. C# is intended to be a simple, modern, general- purpose, object-oriented programming language. The language should provide: The language should provide: – strong type checking, array bounds checking, detection of attempts to use uninitialized variables, and automatic garbage collection – Software robustness, durability, and programmer productivity are important. The language is intended for use in developing software components suitable for deployment in distributed environments. The language is intended for use in developing software components suitable for deployment in distributed environments.

Goals of C# (cont.) Source code portability is very important Source code portability is very important – especially for those programmers already familiar with C and C++. Support for internationalization is very important. Support for internationalization is very important. C# is intended to be suitable for C# is intended to be suitable for – writing applications for both hosted and embedded systems, – ranging from the very large that use sophisticated operating systems, down to the very small having dedicated functions.

Goals of C# (cont.) C# applications are intended to be economical with regard to memory and processing power requirements C# applications are intended to be economical with regard to memory and processing power requirements – the language was not intended to compete directly on performance and size with C or assembly language.

ECMA 334 The representation of C# programs; The representation of C# programs; The syntax and constraints of the C# language; The syntax and constraints of the C# language; The semantic rules for interpreting C# programs; The semantic rules for interpreting C# programs; The restrictions and limits imposed by a conforming implementation of C#. The restrictions and limits imposed by a conforming implementation of C#. The mechanism by which C# programs are transformed for use by a data-processing system; The mechanism by which C# programs are transformed for use by a data-processing system; The mechanism by which C# applications are invoked for use by a data-processing system; The mechanism by which C# applications are invoked for use by a data-processing system;

ECMA 334 (cont.) The mechanism by which input data are transformed for use by a C# application; The mechanism by which input data are transformed for use by a C# application; The mechanism by which output data are transformed after being produced by a C# application; The mechanism by which output data are transformed after being produced by a C# application; The size or complexity of a program and its data that will exceed the capacity of any specific data processing system or the capacity of a particular processor; The size or complexity of a program and its data that will exceed the capacity of any specific data processing system or the capacity of a particular processor; All minimal requirements of a data-processing system that is capable of supporting a conforming implementation. All minimal requirements of a data-processing system that is capable of supporting a conforming implementation.

Common Language Infrastructure (CLI) Written in multiple high-level languages can be executed in different system environments without the need to rewrite those applications to take into consideration the unique characteristics of those environments. Written in multiple high-level languages can be executed in different system environments without the need to rewrite those applications to take into consideration the unique characteristics of those environments.

ECMA 335 Concepts and Architecture Concepts and Architecture – Overall architecture of the CLI – Common Type System (CTS) – Virtual Execution System (VES) – Common Language Specification (CLS) Metadata Definition and Semantics Metadata Definition and Semantics – physical layout (as a file format) – logical contents (as a set of tables and their relationships) – semantics (as seen from a hypothetical assembler, ilasm) CIL Instruction Set CIL Instruction Set – Describes the Common Intermediate Language (CIL) instruction set.

ECMA 335 (cont.) Profiles and Libraries Profiles and Libraries – Overview of the CLI Libraries, – A companion file, CLILibrary.xml, provides details of each class, value type, and interface in the CLI Libraries. Debug Interchange Format Debug Interchange Format – Describes a standard way to interchange debugging information between CLI producers and consumers. Annexes Annexes – Sample programs written in CIL Assembly Language (ILAsm) – machine-readable description of the CIL instruction set – a set of guidelines used in the design of the libraries and portability considerations.

Summary ECMA 334 可參考 ECMA 334 可參考 – The C# Programming Language, by Anders Hejlsberg, Scott Wiltamuth, and Peter Golde (Addison-Wesley, 2003). ECMA 335 可參考 ECMA 335 可參考 – The Common Language Infrastructure Annotated Standard, by James Miller and Susann Ragsdale (Addison-Wesley, 2003).