promise extractors when no promise

[crowding]

arg_env gets the environment of a promise:

del <- function(x, envir=arg_env(x, environment())) {
  force(envir)
  .Internal(remove(x, envir, FALSE))
}

Thing is, promises are not always created with calls; the byte compiler can optimize promise creation away for literals.

library(compiler)
enableJIT(0)
f <- function() {y <- 1; del("y")}
f()
f <- cmpfun(f, options=list(optimize=1))
f() #promises creation optimized away
f <- cmpfun(f, options=list(optimize=2))
f()
# Error in arg_env(x, environment()) (from getpromise.R#39) : Expected promise, got character

• force JIT optimization to 1 on package load?
• maybe fall back on parent.frame if no other (ugh)
• one would like to still only extract the promise if is an argument, and error otherwise?

[crowding]

I can check JIT optimization at package load, but does that affect the compilation that is done when the package is byte-compiled?