From 0cbc314e746420de0affe35afa2d8f8a96c0785d Mon Sep 17 00:00:00 2001
From: Sebastian Fischer <sebf.fischer@gmail.com>
Date: Tue, 31 Oct 2023 18:34:16 +0100
Subject: [PATCH] crate always compiles when input function was compiled

---
 R/crate.R                   | 12 +++++++++++-
 man/crate.Rd                |  4 +++-
 tests/testthat/test_crate.R |  5 +++++
 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/R/crate.R b/R/crate.R
index 9c950056..59a21186 100644
--- a/R/crate.R
+++ b/R/crate.R
@@ -11,6 +11,8 @@
 #'   Parent environment to look up names. Default to [topenv()].
 #' @param .compile (`logical(1)`)\cr
 #'   Whether to jit-compile the function.
+#'   In case the function is already compiled.
+#'   If the input function `.fn` is compiled, this has no effect, and the output function will always be compiled.
 #'
 #' @export
 #' @examples
@@ -27,10 +29,18 @@
 #' f = meta_f(1)
 #' f()
 crate = function(.fn, ..., .parent = topenv(), .compile = TRUE) {
+  assert_flag(.compile)
   nn = map_chr(substitute(list(...)), as.character)[-1L]
   environment(.fn) = list2env(setNames(list(...), nn), parent = .parent)
-  if (.compile) {
+  if (.compile || is_compiled(.fn)) {
     .fn = compiler::cmpfun(.fn)
   }
   return(.fn)
 }
+
+is_compiled = function(x) {
+  tryCatch({
+    capture.output(compiler::disassemble(x))
+    TRUE
+  }, error = function(e) FALSE)
+}
diff --git a/man/crate.Rd b/man/crate.Rd
index d06c672e..a84039ff 100644
--- a/man/crate.Rd
+++ b/man/crate.Rd
@@ -17,7 +17,9 @@ The objects, which should be visible inside \code{.fn}.}
 Parent environment to look up names. Default to \code{\link[=topenv]{topenv()}}.}
 
 \item{.compile}{(\code{logical(1)})\cr
-Whether to jit-compile the function.}
+Whether to jit-compile the function.
+In case the function is already compiled.
+If the input function \code{.fn} is compiled, this has no effect, and the output function will always be compiled.}
 }
 \description{
 Put a function in a "lean" environment that does not carry unnecessary baggage with it (e.g. references to datasets).
diff --git a/tests/testthat/test_crate.R b/tests/testthat/test_crate.R
index 4e692543..d0bbb90e 100644
--- a/tests/testthat/test_crate.R
+++ b/tests/testthat/test_crate.R
@@ -16,4 +16,9 @@ test_that("crate", {
 test_that("compilation works", {
   expect_error(compiler::disassemble(crate(function() NULL, .compile = FALSE)), regexp = "function is not compiled")
   expect_error(compiler::disassemble(crate(function() NULL, .compile = TRUE)), regexp = NA)
+
+  f = function() NULL
+  fc = compiler::cmpfun(f)
+
+  expect_true(is_compiled(fc))
 })