Eiffel 编程

欢迎来到维基教科书上的“Eiffel for Everyone”。

关于 Eiffel

Eiffel 最初由 Bertrand Meyer 开发，它拥有简洁且易读的语法。该语言的许多设计原则都强调代码的可读性和可维护性。

由于其对语言特性（如多重继承和泛型（尤其是受约束的泛型））的出色实现，使用 Eiffel 表达复杂思想所需的代码量比其他编程语言要少。强大的类型系统以及全面的静态类型检查使程序能够轻松地扩展规模，并以其他语言难以实现的方式进行演化。

Eiffel 由于语言过于冗长而受到批评，并且很容易让人对它的一些结构（如循环语句）的冗长性感到厌烦。然而，我发现其他语言（例如 C 家族，包括 Java 和 C++）经常以简洁著称，但在复杂类型的声明和使用方面却非常冗长。

指导设计原则

一切皆为对象
契约式设计
单一入口，单一出口
开闭原则
命令/查询分离

过去、现在和未来的版本

Eiffel 非特性 - 在 Eiffel 中你不会看到什么

Eiffel 特性 - 语言的独特性

  Contracts and contract inheritance
  Rich set of assertions
  Multiple Inheritance
  Constrained Genericity
  Type-safe agents (also known as closures)
  Void Safety
  SCOOP (Simple Concurrent Object Oriented Programming)

类的解剖

类的组成部分

   Eiffel Names
    Reserved words
    Notes or indexing
    Name
    Inherit
    create
    features
    more notes
    the end
  Features
    Attributes
    Functions
       The Uniform Access Principle
    Procedures
       Commands vs Queries

基本要素

  Implementing Features
  Local Variables
  Creating objects
  Assignment
  Calling features
  Operators
  Expressions
  Copying Objects
  Comparing Objects
  Conditional control
     The if statement
     The inspect statement
  Iteration—looping
  Flow of Control
  Attachment Checking and Locals (e.g. if attached l_foo as al_foo then ... end)

基本类型

  Expanded Types
    INTEGERs of Various Sizes
    REALs
    CHARACTERs
    BOOLEAN
  Reference Types
    ANY
    STRINGs
    DATE
  Containers

契约

  What's required
  What's ensured
  Invariants: What is always true (about a class)
  Checks
  Variants and loop contracts

继承

  Why its useful
  How it works
    LSP
  Renaming
  Redefining
  Undefining
  Extending
  Non-conforming inheritance
  Implementation inheritance
  Multiple inheritance
  Inheritance of Contracts

泛型

  With Containers
  With Algorithms
  Constrained Genericity
  Example: Hash tables

元组

 Uses for tuples
 Returning multiple values from a function
 Named tuples

代理

 As a way of iterating over containers
 Using agents
 Closed and Open Arguments
 Agent declarations

库

高级主题

 Covariance and Anchored Types

非常高级的主题

  Memory Management Details
     Garbage Collection Limitations
  Interfacing to Other Languages
  .Net Support
  Low-level Debugging

补充阅读