Fix Term's "get_type()" implementation

UPGRADE.md

@@ -19,8 +19,9 @@ This document is intended to simplify upgrading to newer versions by extending t
    See also
    [enif\_send](https://www.erlang.org/doc/man/erl_nif.html#enif_send).
 
-3. As `Term::get_type` is now implemented using `enif_get_type`, some cases of
-   the `TermType` `enum` are changed, removed, or added:
+3. As `Term::get_type` is now implemented using `enif_get_type` on all
+   non-Windows systems, some cases of the `TermType` `enum` are changed,
+   removed, or added (on all systems):
    1. `EmptyList` is dropped, `List` is returned for both empty and non-empty
       lists
    2. `Exception` is dropped

rustler/src/dynamic.rs

@@ -1,3 +1,5 @@
+use std::ffi::c_double;
+
 #[cfg(feature = "nif_version_2_15")]
 use rustler_sys::ErlNifTermType;
 
@@ -43,7 +45,7 @@ impl From<ErlNifTermType> for TermType {
 }
 
 pub fn get_type(term: Term) -> TermType {
-    if cfg!(nif_version_2_15) {
+    if cfg!(feature = "nif_version_2_15") && !cfg!(target_family = "windows") {
         term.get_erl_type().into()
     } else if term.is_atom() {
         TermType::Atom
@@ -56,7 +58,11 @@ pub fn get_type(term: Term) -> TermType {
     } else if term.is_map() {
         TermType::Map
     } else if term.is_number() {
-        TermType::Float
+        if term.is_float() {
+            TermType::Float
+        } else {
+            TermType::Integer
+        }
     } else if term.is_pid() {
         TermType::Pid
     } else if term.is_port() {
@@ -98,4 +104,15 @@ impl<'a> Term<'a> {
     impl_check!(is_port);
     impl_check!(is_ref);
     impl_check!(is_tuple);
+
+    pub fn is_float(self) -> bool {
+        let mut val: c_double = 0.0;
+        unsafe {
+            rustler_sys::enif_get_double(self.get_env().as_c_arg(), self.as_c_arg(), &mut val) == 1
+        }
+    }
+
+    pub fn is_integer(self) -> bool {
+        self.is_number() && !self.is_float()
+    }
 }

rustler/src/term.rs

@@ -124,7 +124,7 @@ impl<'a> Term<'a> {
 
     #[cfg(feature = "nif_version_2_15")]
     pub fn get_erl_type(&self) -> rustler_sys::ErlNifTermType {
-        unsafe { rustler_sys::enif_term_type(self.env.as_c_arg(), &self.as_c_arg()) }
+        unsafe { rustler_sys::enif_term_type(self.env.as_c_arg(), self.as_c_arg()) }
     }
 }
 

rustler_sys/build.rs

@@ -848,7 +848,7 @@ fn build_api(b: &mut dyn ApiBuilder, opts: &GenerateOptions) {
         b.func(
             "ErlNifTermType",
             "enif_term_type",
-            "env: *mut ErlNifEnv, term: *const ERL_NIF_TERM",
+            "env: *mut ErlNifEnv, term: ERL_NIF_TERM",
         );
 
         b.func("c_int", "enif_is_pid_undefined", "pid: *const ErlNifPid");

rustler_tests/lib/rustler_test.ex

@@ -47,6 +47,7 @@ defmodule RustlerTest do
   def term_cmp(_, _), do: err()
   def term_internal_hash(_, _), do: err()
   def term_phash2_hash(_), do: err()
+  def term_type(_term), do: err()
 
   def sum_map_values(_), do: err()
   def map_entries_sorted(_), do: err()

rustler_tests/native/rustler_test/src/lib.rs

@@ -30,6 +30,7 @@ rustler::init!(
         test_term::term_cmp,
         test_term::term_internal_hash,
         test_term::term_phash2_hash,
+        test_term::term_type,
         test_map::sum_map_values,
         test_map::map_entries_sorted,
         test_map::map_from_arrays,

rustler_tests/native/rustler_test/src/test_term.rs

@@ -7,6 +7,19 @@ mod atoms {
         equal,
         less,
         greater,
+        // Term types
+        atom,
+        binary,
+        float,
+        fun,
+        integer,
+        list,
+        map,
+        pid,
+        port,
+        reference,
+        tuple,
+        unknown,
     }
 }
 
@@ -40,3 +53,21 @@ pub fn term_internal_hash(term: Term, salt: u32) -> u32 {
 pub fn term_phash2_hash(term: Term) -> u32 {
     term.hash_phash2()
 }
+
+#[rustler::nif]
+pub fn term_type(term: Term) -> Atom {
+    match term.get_type() {
+        rustler::TermType::Atom => atoms::atom(),
+        rustler::TermType::Binary => atoms::binary(),
+        rustler::TermType::Fun => atoms::fun(),
+        rustler::TermType::List => atoms::list(),
+        rustler::TermType::Map => atoms::map(),
+        rustler::TermType::Integer => atoms::integer(),
+        rustler::TermType::Float => atoms::float(),
+        rustler::TermType::Pid => atoms::pid(),
+        rustler::TermType::Port => atoms::port(),
+        rustler::TermType::Ref => atoms::reference(),
+        rustler::TermType::Tuple => atoms::tuple(),
+        rustler::TermType::Unknown => atoms::unknown(),
+    }
+}

rustler_tests/test/term_test.exs

@@ -67,4 +67,17 @@ defmodule RustlerTest.TermTest do
 
     assert unique > 50
   end
+
+  test "term type" do
+    assert RustlerTest.term_type(:foo) == :atom
+    assert RustlerTest.term_type("foo") == :binary
+    assert RustlerTest.term_type(42.2) == :float
+    assert RustlerTest.term_type(42) == :integer
+    assert RustlerTest.term_type(%{}) == :map
+    assert RustlerTest.term_type([]) == :list
+    assert RustlerTest.term_type({:ok, 42}) == :tuple
+    assert RustlerTest.term_type(self()) == :pid
+    assert RustlerTest.term_type(& &1) == :fun
+    assert RustlerTest.term_type(make_ref()) == :reference
+  end
 end