4.5 Expansion Analyzers🔗

An expansion analyzer examines the fully expanded form of a program and reports facts about it as a syntax property bundle whose syntax paths refer to subforms of the expanded program. Resyntax translates those paths back to the corresponding subforms of the original unexpanded program and attaches the reported properties to them, making information that is only discoverable after macro expansion available to refactoring rules. Expansion analyzers are an as-yet undocumented work in progress; a future edition of this grimoire will describe them properly.