A snapshot of an F# source file.

An identifier of an F# project. This serves to identify the same project as it changes over time and enables us to clear obsolete data from caches.

A snapshot of an F# project. This type contains all the necessary information for type checking a project.

All required information for compiling a project except the source files and referenced projects. It's kept separate so it can be reused for different stages of a project snapshot and also between changes to the source files.

An on-disk reference needed for project compilation.