Nim 0.10.2发布,命令式编程语言

　　Nimrod (已改名为 Nim)是一个新型的静态类型、命令式编程语言，支持过程式、函数式、面向对象和泛型编程风格而保持简单和高效。Nimrod从Lisp继承来的一个特殊 特性--抽象语法树(AST)作为语言规范的一部分，可以用作创建领域特定语言的强大宏系统。

　　Nimrod是一个编译型的具有垃圾收集的系统编程语言，有着极其卓越的生产/性能比。Nimrod的设计集中在三个E上：即效率(efficiency)、表达能力(expressiveness)和优雅(elegance)。

　　Nim 0.10.2 发布，此版本包括大量的语言改进，一些可能会跟现有的代码大不相同。为了大家的方便，添加了一个新的工具 nimfix，使用最新版本的编译器，帮助转换现有的项目。

　　Nim 很快就要开始 1.0 版本了，1.0 版本将不会有太多重大的改进。现阶段添加了新的模块 asyncdispatch ，帮助便携高效的 web 服务器应用，使用非阻塞代码。Nim 添加了一个内置线程池，为了使用 spawn 进行轻量级的线程开发。

　　此版本废弃了T "T" 和 "P" 类型前缀，添加了一个新的可搜索的论坛，添加了新的网站和改进现有的文档生成器 docgen。

　　Nim 将会很快到达 1.0 版本，除了 bug 修复，计划添加两个重要特性：

• static[T] needs to be defined precisely and the bugs in the implementation need to be fixed.

• Overloading of the assignment operator is required for some generic containers and needs to be implemented.

更新日志

影响向后兼容方面的改进

• The language has been renamed from Nimrod to Nim. The name of the compiler changed from nimrod to nim too.

• system.fileHandle has been renamed to system.getFileHandle to prevent name conflicts with the new type FileHandle.

• Comments are now not part of the AST anymore, as such you cannot use them in place of discard.

• Large parts of the stdlib got rid of the T/P type prefixes. Instead most types now simply start with an uppercased letter. The so called "partial case sensitivity" rule is now active allowing for code like var foo: Foo in more contexts.

• String case (or any non-ordinal case) statements without 'else' are deprecated.

• Recursive tuple types are not allowed anymore. Use object instead.

• The PEGS module returns nil instead of "" when an optional capture fails to match.

• The re module returns nil instead of "" when an optional capture fails to match.

• The "symmetric set difference" operator (-+-) never worked and has been removed.

• defer is a keyword now.

• func is a keyword now.

• The using language feature now needs to be activated via the new {.experimental.} pragma that enables experimental language features.

• Destructors are now officially experimental.

• Standalone except and finally statements are deprecated now. The standalone finally can be replaced with defer, standalone except requires an explicit try.

• Operators ending in > are considered as "arrow like" and have their own priority level and are right associative. This means that the => and -> operators from the future module work better.

• Field names in tuples are now ignored for type comparisons. This allows for greater interoperability between different modules.

• Statement lists are not converted to an implicit do block anymore. This means the confusing nnkDo nodes when working with macros are gone for good.

语言组件

• The new concurrency model has been implemented including locks sections, lock levels and object field guards.

• The parallel statement has been implemented.

• deepCopy has been added to the language.

• The builtin procCall can be used to get super-like functionality for multi methods.

• There is a new pragma {.experimental.} that enables experimental language features per module, or you can enable this features on a global level with the --experimental command line option.

编译器组件

• The compiler now supports mixed Objective C / C++ / C code generation: The modules that use importCpp or importObjc are compiled to C++ or Objective C code, any other module is compiled to C code. This improves interoperability.

• There is a new parallel statement for safe fork&join parallel computing.

• guard and lock pragmas have been implemented to support safer concurrent programming.

• The following procs are now available at compile-time:

  math.sqrt, math.ln, math.log10, math.log2, math.exp, math.round,
  math.arccos, math.arcsin, math.arctan, math.arctan2, math.cos, math.cosh,
  math.hypot, math.sinh, math.sin, math.tan, math.tanh, math.pow,
  math.trunc, math.floor, math.ceil, math.fmod,
  os.getEnv, os.existsEnv, os.dirExists, os.fileExists,
  system.writeFile

• Two backticks now produce a single backtick within an emit or asm statement.

• There is a new tool, nimfix to help you in updating your code from Nimrod to Nim.

• The compiler's output has been prettified.

库组件

• Added module fenv to control the handling of floating-point rounding and exceptions (overflow, division by zero, etc.).

• system.setupForeignThreadGc can be used for better interaction with foreign libraries that create threads and run a Nim callback from these foreign threads.

• List comprehensions have been implemented as a macro in the future module.

• The new Async module (asyncnet) now supports SSL.

• The smtp module now has an async implementation.

• Added module asyncfile which implements asynchronous file reading and writing.

• osproc.kill has been added.

• asyncnet and asynchttpserver now support SO_REUSEADDR.

Bug 修复

• nil and NULL are now preserved between Nim and databases in the db_* modules.

• Fixed issue with OS module in non-unicode mode on Windows.

• Fixed issue with x.low (#1366).

• Fixed tuple unpacking issue inside closure iterators (#1067).

• Fixed ENDB compilation issues.

• Many asynchttpserver fixes.

• Macros can now keep global state across macro calls (#903).

• osproc fixes on Windows.

• osproc.terminate fixed.

• Improvements to exception handling in async procedures. (#1487).

• try now works at compile-time.

• Fixes T = ref T to be an illegal recursive type.

• Self imports are now disallowed.

• Improved effect inference.

• Fixes for the math module on Windows.

• User defined pragmas will now work for generics that have been instantiated in different modules.

• Fixed queue exhaustion bug.

• Many, many more.