Example
Type abbreviations allow you to create aliases on existing types to give them a more meaningful senses.
// Name is an alias for a string
type Name = string
// PhoneNumber is an alias for a string
type PhoneNumber = string
Then you can use the alias just as any other type:
// Create a record type with the alias
type Contact = {
Name : Name
Phone : PhoneNumber }
// Create a record instance
// We can assign a string since Name and PhoneNumber are just aliases on string type
let c = {
Name = "Foo"
Phone = "00 000 000" }
printfn "%A" c
// Output
// {Name = "Foo";
// Phone = "00 000 000";}
Be careful, aliases does not check for type consistency. This means that two aliases that target the same type can be assigned to each other:
let c = {
Name = "Foo"
Phone = "00 000 000" }
let d = {
Name = c.Phone
Phone = c.Name }
printfn "%A" d
// Output
// {Name = "00 000 000";
// Phone = "Foo";}
