Extract the interfacer specification for a function

Extract the interfacer specification for a function

Usage

get_iface(fn, param = names(formals(fn))[[1]])

Arguments

fn

the function

param

the parameter name (defaults to first parameter)

Value

the iface on the parameter

Examples

my_iface = iface(
  col1 = integer + group_unique ~ "an integer column",
  .default = test_df
)

# the function x defines a formal `df` with default value of `my_iface`
# this default value is used to validate the structure of the user supplied
# value when the function is called.
x = function(df = my_iface, ...) {
  df = ivalidate(df,...)
  return(df)
}

get_iface(x,"df")
#> A dataframe containing the following columns: 
#> * col1 (integer + group_unique) - an integer column
#> Any grouping allowed.
#> A default value is defined.