- er-macro-transformer TRANSFORMERprocedure
Returns an explicit-renaming macro transformer procedure created from the procedural macro body TRANSFORMER, which is a procedure of three arguments.
This procedure will be called on expansion with the complete s-expression of the macro invocation, a rename procedure that hygienically renames identifiers and a comparison procedure that compares (possibly renamed) identifiers (see the section "Explicit renaming macros" below for a detailed explanation on non-R5RS macros).
Implementation note: this procedure currently just returns its argument unchanged and is available for writing low-level macros in a more portable fashion, without hard-coding the signature of a transformer procedure.