I tried googling this but I couldn't find a collection of words that guided me to what I am trying to do. I am trying to solve Project Euler Problem 54, and I have this rather ridiculous function:...

Does F# support pattern matching of a discriminated union member instance by criteria other than the Identifier pattern? For example, imagine that I want to match on the underlying shape of the da...

I'm learning F# by writing a recursive descent parser using active patterns. Since all my rules or partial active patterns I need to combine them in different manners, but I'm getting really frust...

I've defined an expression tree structure in F# as follows: type Num = int type Name = string type Expr = | Con of Num | Var of Name | Add of Expr * Expr | Sub of Expr * Expr | Mult of Expr ...

Is it possible to use active patterns within discrimated union type declarations? To be more precise, consider the following toy example: type T = | A of int | B let (|Negative|_|) t = matc...

I have a Dictionary over which I initially iterated thusly: myDictionary |> Seq.iter (fun kvp -> doSomething kvp.Key kvp.Value) Later, I discovered that I could make use of the KeyValue act...

This active pattern compiles with F# 2.0: let (|Value|_|) value = // 'a -> 'T option match box value with | :? 'T as x -> Some x | _ -> None but, in F# 3.0, emits the error: Activ...

The active pattern in this question fails to compile after upgrading to VS 2012 RTM. It provides a way to do a type test and match a literal within a single pattern. For example: let (|Value|_|) v...

For an inline function one could create a constraint like: let inline implicit arg = ( ^a : (static member op_Implicit : ^b -> ^a) arg) requiring the given operator or member on the argument...

Given the following contrived active pattern: let (|TypeDef|_|) (typeDef:Type) (value:obj) = if obj.ReferenceEquals(value, null) then None else let typ = value.GetType() if typ.IsGenericType &...

I defined the active pattern "Expression" as follows: let (|Expression|_|) expression _ = Some(expression) Now I'm trying to use it in this way: match () with | Expression((totalWidth - wLeft -...

I found this useful article on using Active Patterns with Regular Expressions: http://www.markhneedham.com/blog/2009/05/10/f-regular-expressionsactive-patterns/ The original code snippet used in ...

I'm not sure if non-static public member active patterns are allowed but you can define them without the compiler complaining. If they are allowed what's the syntax for matching against one? The co...