Visual F# 4.0 发布，此版本现已提供下载：

https://www.visualstudio.com/downloads/download-visual-studio-vs。

F# 4.0 包含新的语言特性：

• 构造函数作为一级函数

• 可变值的使用简化

• 支持高维的数组

• 支持方法中的静态参数

• 简化列表的语法

• 简化 printf 函数的使用

• GC 优化提升性能

API 改进：

• 标准化和扩展 Array, List 和 Seq 模块

• New APIs for 4.0: chunkBySize, contains, except, findBack, findInstanceBack, indexed, item, mapFold, mapFoldBack, sortByDescending, sortDescending, splitInto, tryFindBack, tryFindIndexBack, tryHead, tryItem, tryLast

• 其他新 API
  

• Option.filter, Option.toObj, Option.ofObj, Option.toNullable, Option.ofNullable

• String.filter

• Checked.int8, Checked.uint8

• Async.AwaitTask (non-generic)

• WebClient.AsyncDownloadFile, WebClient.AsyncDownloadData

• tryUnbox, isNull

其他值得关注的改进：

• New active pattern to match constant Decimal in quotations

• Slicing support for lists

• Support for consuming high-rank (> 4) arrays

• Support for units of measure in printf-family functions

• Support for constructors/class names as first-class functions

• Improved exception stack traces in async code

• Automatic mutable/ref conversion

• Support for static arguments to provided methods

• Support for non-nullable provided types

• Added NonStructuralComparison module containing non-structural comparison operators

• Support for rational exponents in units of measure

• Give fsi.exe, fsiAnyCpi.exe nice icons

• Microsoft. optional in namepsace paths from FSharp.Core

• Support for extension properties in object initializers

• Pre-support (not yet used) for additional nativeptr intrinsics

• Simplified, more robust resolution of type references in quotations

• Support for inheritance of types that have multiple interface instantiations

• Extended preprocessor grammar

• Support for implicit quotation of expressions used as method arguments

• Support for multiple properties in [<StructuredFormatDisplay>]

• Eliminate tuple allocation for implicitly returned formal arguments

• Perf: fsc.exe now uses GCLatencyMode.Batch

• Perf: Improved hash/compare/distinctBy/groupBy performance

• Perf: Seq.toArray perf improvement

• Perf: Use OptimizedClosures.FSharpFunc in seq.fs where applicable

• Perf: Use literals and mutable variables instead of ref cells for better performance in SHA1 calc

• Perf: Use smart blend of System.Array.Copy and iterative copy for array copies

• Perf: Change Seq.toList to mutation-based to remove reliance on List.rev

• Perf: Change pdbClose to test if files are locked before inducing GCs

• Perf: Use server GC mode for compiler

Visual Studio 方面的改进：

• Updated all templates (except tutorial) to include AssemblyInfo.fs setup in the same manner as default C# project templates

• Add keyboard shortcuts for FSI reset and clear all

• Improved debugger view for Map values

• Improved performance reading stdout/stderr from fsi.exe to F# Interactive window

• Support for VS project up-to-date check

• Improved project template descriptions, make it clearer how to target Xamarin platforms

• Intellisense completion in object initializers

• Add menu entry "Open folder in File Explorer" on folder nodes

• Intellisense completion for named arguments

• Alt+Enter sends current line of code to interactive if there is no selection

• Support for debugging F# scripts with the VS debugger

• Add support for hexadecimal values (like 0xFF) ??to MSBuild property BaseAddress

• Updated menu icons used for F# interactive to align with other VS interactive windows

此外还有写 bug 修复，详细改进内容请看更新日志。

F#是由微软发展的为微软.NET语言提供运行环境的程序设计语言，是函数编程语言（FP，Functional Programming），函数编程语言最重要的基础是Lambda Calculus。它是基于OCaml的，而OCaml是基于ML函 数程式语言。有时F# 和 OCaml 的程式是可以交互编译的。

F#已经接近成熟，支援Higher-Order Function、Currying、Lazy Evaluation、Continuations、Pattern Matching、Closure、List Processing、Meta-Programming。这是一个用于显示.NET在不同编程语言间互通的程序设计，可以被.NET中的任意其它代码编 译和调用。

F#将被集成在Visual Studio 2010中，含有对.Net Framework的完全支持。