Using `isTRUE()` on a symbol `T` based on a sys.call

is there a version of isTRUE() that would also work on a symbol T?

To be clear, I don't mean the actual shorthand for TRUE which is T but a value of the class symbol.

This comes from a function that has saved its information in a sys.call() object - which saves a TRUE (i.e. a logical value) but when you input a T and then use sys.call() a symbol is saved rather than a logical value.

An example here:

test_fun <- function(x, mc){
  out <- list()
  out$a <- rnorm(x)
  out$sys_call <- sys.call()
  out$match_call <- match.call()
  return(out)
}

Where then if I want to check the resulting object by accessing the $call$mc aspect, I don't identify the T as a logical value.

Here the main issue:

main_example <- test_fun(2, mc = T)
main_example$sys_call$mc # showing T
main_example$match_call$mc # showing T

main_example$sys_call$mc == TRUE # resulting in FALSE
main_example$match_call$mc == TRUE # resulting in FALSE
isTRUE(main_example$sys_call$mc) # resulting in FALSE
isTRUE(main_example$match_call$mc) # resulting in FALSE

str(main_example$sys_call$mc) # showing that T is a symbol, not logical
str(main_example$match_call$mc) # showing that T is a symbol, not logical

I'm well aware that I should never use T but rather TRUE but how do I deal with a user inputting T in my package and always checking whether it's true?

Just using as.logical() throws an error:

cannot coerce type 'symbol' to vector of type 'logical'

Something like this would work, but it's a bit tedious... There must be a better way to do this :)

is.symbol(main_example$match_call$mc) && main_example$match_call$mc == as.symbol("T")

Thanks!

Some more fun comparing sys.call and match.call:

# here a small but unsatisfying advantage of match.call v sys.call
test_fun(2, T)$sys_call$mc
test_fun(2, T)$match_call$mc
# unsatisfying because it still does not recognise it as TRUE but just as symbol T
# but it's better than sys.call
is.logical(test_fun(2, T)$sys_call$mc)
is.logical(test_fun(2, T)$match_call$mc)

test_fun(2, mc = T)$sys_call$mc
test_fun(2, mc = T)$match_call$mc
# both fail to identify logical
is.logical(test_fun(2, mc = T)$sys_call$mc)
is.logical(test_fun(2, mc = T)$match_call$mc)

# here the advantage of match.call v sys.call
test_fun(2, TRUE)$sys_call$mc
test_fun(2, TRUE)$match_call$mc

# here the advantage of match.call v sys.call
is.logical(test_fun(2, TRUE)$sys_call$mc) 
is.logical(test_fun(2, TRUE)$match_call$mc)

test_fun(2, mc = TRUE)$sys_call$mc
test_fun(2, mc = TRUE)$match_call$mc

is.logical(test_fun(2, mc = TRUE)$sys_call$mc)
is.logical(test_fun(2, mc = TRUE)$match_call$mc)