A version of substitute that evaluates its first argument.

Source: R/substitute.r

This version of substitute is needed because substitute does not evaluate it's first argument, and it's often useful to be able to modify a quoted call.

substitute_q(x, env)

Arguments

x

a quoted call

env

an environment, or something that behaves like an environment (like a list or data frame), or a reference to an environment (like a positive integer or name, see as.environment for more details)

Examples

x <- quote(a + b)
substitute(x, list(a = 1, b = 2))
#> x
substitute_q(x, list(a = 1, b = 2))
#> 1 + 2