Question

Is it possible to split an F# module across files?

According to the book I have it is, but the book is probably outdated (Foundations of F#)

Answer 1

Apparently not:

C:\temp\Tim>type 1.fs 2.fs  1.fs   #light module Module  let sayHello1 = printfn 'Hello, '  2.fs   #light module Module  let sayHello2 = printfn 'world!'  C:\temp\Tim>fsc 1.fs 2.fs Microsoft F# Compiler, (c) Microsoft Corporation, All Rights Reserved F# Version 1.9.6.2, compiling for .NET Framework Version v2.0.50727  2.fs(2,1): error FS0191: An implementation of the file or module Module has already been given. 

Update: the error has changed in F# 4.0, it is now:

error FS0248: Two modules named ‘Module’ occur in two parts of this assembly

where Module is the fully qualified name of your assembly, including the namespace part.