eda-tools/b2/SUBST

REF=R[0-9]* {
	T=R
	VAL=* { R=$$#R }
	TOL = 5%
	FN=*% { TOL=${$#%} }
	break REF
//	end break again
}

/*
pattern: () * ? .
subst:  $1 ... $field

substring:
  $1, $2, ...
variable:
  $foo, ...
with curly braces:
  ${foo}, ...
unit conversion:
  $foo#V
  ${1#R}
input variable:
  $$
*/