String interpolation is a useful way of specifying a character string which
depends on values in a certain environment. It allows for string creation
which is easier to read and write when compared to using e.g.
paste or sprintf. The (template) string can
include expression placeholders of the form ${expression} or
$[format]{expression}, where expressions are valid R expressions that
can be evaluated in the given environment, and format is a format
specification valid for use with sprintf.
stringterpolate(string, env = parent.frame())A template character string.
The environment in which to evaluate the expressions.
An interpolated character string.