Case Study: Westat achieves function-style macros that run DATA/PROC steps with SAS

Westat creates function-style flexibility in a macro

Westat senior VP Mike Rhoads tackled a common SAS programming challenge: users wanted function-style macros that could be embedded inside SAS statements (via %SYSFUNC) but still perform full DATA or PROC steps behind the scenes—a capability that traditional function-style macros lacked. A practical example was expanding complex user-specified variable lists into explicit variable names, which normally requires PROC TRANSPOSE and PROC SQL and thus couldn’t be done inside a simple macro expression.

Rhoads’ “Macro Function Sandwich” solves this by layering an outer user-facing macro, a user-written PROC FCMP function (called with %SYSFUNC) and an inner macro invoked via RUN_MACRO. The inner macro runs the necessary DATA/PROC steps (e.g., PROC TRANSPOSE + PROC SQL to expand variable lists) and returns text to the FCMP function and then to the outer macro. The result: function-style macros can now leverage the full power of SAS procedures, removing previous restrictions and enabling more flexible, maintainable solutions for missing language features.

Westat

Mike Rhoads

Vice President