reformulas (random effects formulas) is a utility package for processing "lme4-style" random effects formulas in R (i.e., formulas where the random effects are included in the form (f|g) as components of an overall model formula, where f represents a sub-formula for the varying effects and g represents a sub-formula for the grouping variable(s).

The package contains functions like findbars (extract terms containing |, i.e. random-effects terms), nobars (drop terms containing bars from a formula), etc.. The goal of reformulas is to be used upstream of lme4 and glmmTMB (and possibly other packages) as a unified toolkit for processing formulas.