Curried comparison active patterns for use directly in a match expression.

Parse active patterns — match and extract parsed values from strings.

Every partial pattern here returns a struct ValueOption via [<return: Struct>]. A plain partial pattern allocates one FSharpOption per evaluated match arm, which for patterns this small — used in hot parse and validation loops — is the entire cost of the match. The attribute is invisible at the use site: the syntax of a match arm is identical either way.