tar_pep_foreach: Target factory for arbitrary functions on PEP samples
In databio/unitar: Share targets across projects and users

This target factory creates a target for each element of a PEP. You can name the targets using a pattern that uses brackets to indicate sample attributes, like 'sample_name'.

tar_pep_foreach(
  p,
  tpattern,
  func,
  argvals_pattern,
  argtypes,
  argnames = NULL,
  combine_tname = NULL,
  combine_func_name = "list"
)

`p`	PEP.
`tpattern`	Target name, with patterns allowed
`func`	Function to call
`argvals_pattern`	List of arg values, with patterns allowed
`argtypes`	List of arg types (use 'symbol' for targets)
`argnames`	List of arg names
`combine_tname`	Target name for a combined target that merges all of the individual targets
`combine_func_name`	Character vector of a function that will combine them.