This article gives an overview how types are accessed in F# with a combination of features related to static typing, dynamic typing, and type inference. Static Typing Static type checking ensures, at compile time, that the program is free from most kinds of type errors. The source code editor can highlight such errors as soon as they are written out. Static type checking in F# probably goes further than in any other strongly typed language: By default, types defined in F# cannot be null. This[...]

This article gives an overview how types are accessed in F# with a combination of features related to static typing, dynamic typing, and type inference. Static Typing Static type checking ensures, at compile time, that the program is free from most kinds of type errors. The source code editor can highlight such errors as soon as they are written out. Static type checking in F# probably goes further than in any other strongly typed language: By default, types defined in F# cannot be null. This eradicates a[...]

F# provides literal expressions for tuples, F# lists, arrays, enumerables, and other generic types. The elements of a tuple expression are separated by commas. The elements of all other kinds of list-like expressions are separated by semicolons. F# ExpressionF# Type RepresentationC# Type Representation 17, 3, 8 int * int * int Tuple<int, int, int> [17; 3; 8] int list FSharpList<int> [|17; 3; 8|] int[] int[] seq {yield 17; yield 3; yield 8} int seq IEnumerable<int> Not[...]

F# provides literal expressions for tuples, F# lists, arrays, enumerables, and other generic types. The elements of a tuple expression are separated by commas. The elements of all other kinds of list-like expressions are separated by semicolons. F# Expression F# Type Representation C# Type Representation 17, 3, 8 int * int * int Tuple<int, int, int> [17; 3; 8] int list FSharpList<int> [|17; 3; 8|] int[] int[] seq {yield 17; yield 3; yield[...]

C# 4.0 allows to declare variance compatibility for delegates and interfaces. This means, for instance, that one can assign an IEnumerable<Cat> to an IEnumerable<Animal>.  The term variance compatibility, in this context, defines the kind of assignment compatibility between two closed generic types, which exists when the parameters of those types are derived from each other (or are themselves variant to each other). In other [...]