From 05a50803321d2418b15382b06f23f1d466857b9f Mon Sep 17 00:00:00 2001
From: Benedikt Reinartz <filmor@gmail.com>
Date: Thu, 24 Aug 2023 10:13:07 +0200
Subject: [PATCH] Implement get_type using enif_term_type (#538)

---
 rustler/src/dynamic.rs             | 43 ++++++++++++++++++++++--------
 rustler/src/term.rs                |  5 ++++
 rustler/src/types/list.rs          |  2 +-
 rustler/src/wrapper/check.rs       |  1 -
 rustler_sys/src/rustler_sys_api.rs |  1 +
 5 files changed, 39 insertions(+), 13 deletions(-)

diff --git a/rustler/src/dynamic.rs b/rustler/src/dynamic.rs
index 2ffa2f7b..ad73f888 100644
--- a/rustler/src/dynamic.rs
+++ b/rustler/src/dynamic.rs
@@ -1,3 +1,6 @@
+#[cfg(feature = "nif_version_2_15")]
+use rustler_sys::ErlNifTermType;
+
 use crate::wrapper::check;
 use crate::Term;
 
@@ -5,12 +8,11 @@ use crate::Term;
 pub enum TermType {
     Atom,
     Binary,
-    EmptyList,
-    Exception,
     Fun,
     List,
     Map,
-    Number,
+    Integer,
+    Float,
     Pid,
     Port,
     Ref,
@@ -18,23 +20,43 @@ pub enum TermType {
     Unknown,
 }
 
+#[cfg(feature = "nif_version_2_15")]
+impl From<ErlNifTermType> for TermType {
+    fn from(term_type: ErlNifTermType) -> Self {
+        use ErlNifTermType::*;
+        use TermType::*;
+        match term_type {
+            ERL_NIF_TERM_TYPE_ATOM => Atom,
+            ERL_NIF_TERM_TYPE_BITSTRING => Binary,
+            ERL_NIF_TERM_TYPE_FLOAT => Float,
+            ERL_NIF_TERM_TYPE_FUN => Fun,
+            ERL_NIF_TERM_TYPE_INTEGER => Integer,
+            ERL_NIF_TERM_TYPE_LIST => List,
+            ERL_NIF_TERM_TYPE_MAP => Map,
+            ERL_NIF_TERM_TYPE_PID => Pid,
+            ERL_NIF_TERM_TYPE_PORT => Port,
+            ERL_NIF_TERM_TYPE_REFERENCE => Ref,
+            ERL_NIF_TERM_TYPE_TUPLE => Tuple,
+            _ => Unknown,
+        }
+    }
+}
+
 pub fn get_type(term: Term) -> TermType {
-    if term.is_atom() {
+    if cfg!(nif_version_2_15) {
+        term.get_erl_type().into()
+    } else if term.is_atom() {
         TermType::Atom
     } else if term.is_binary() {
         TermType::Binary
-    } else if term.is_empty_list() {
-        TermType::EmptyList
-    } else if term.is_exception() {
-        TermType::Exception
     } else if term.is_fun() {
         TermType::Fun
-    } else if term.is_list() {
+    } else if term.is_list() || term.is_empty_list() {
         TermType::List
     } else if term.is_map() {
         TermType::Map
     } else if term.is_number() {
-        TermType::Number
+        TermType::Float
     } else if term.is_pid() {
         TermType::Pid
     } else if term.is_port() {
@@ -68,7 +90,6 @@ impl<'a> Term<'a> {
     impl_check!(is_atom);
     impl_check!(is_binary);
     impl_check!(is_empty_list);
-    impl_check!(is_exception);
     impl_check!(is_fun);
     impl_check!(is_list);
     impl_check!(is_map);
diff --git a/rustler/src/term.rs b/rustler/src/term.rs
index d9a3e149..6f26d2f6 100644
--- a/rustler/src/term.rs
+++ b/rustler/src/term.rs
@@ -121,6 +121,11 @@ impl<'a> Term<'a> {
                 as u32
         }
     }
+
+    #[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()) }
+    }
 }
 
 impl<'a> PartialEq for Term<'a> {
diff --git a/rustler/src/types/list.rs b/rustler/src/types/list.rs
index 4dae2319..342d45f6 100644
--- a/rustler/src/types/list.rs
+++ b/rustler/src/types/list.rs
@@ -44,7 +44,7 @@ pub struct ListIterator<'a> {
 
 impl<'a> ListIterator<'a> {
     fn new(term: Term<'a>) -> Option<Self> {
-        if term.is_list() || term.is_empty_list() {
+        if term.is_list() {
             let iter = ListIterator { term };
             Some(iter)
         } else {
diff --git a/rustler/src/wrapper/check.rs b/rustler/src/wrapper/check.rs
index b08302de..ae9883bb 100644
--- a/rustler/src/wrapper/check.rs
+++ b/rustler/src/wrapper/check.rs
@@ -11,7 +11,6 @@ macro_rules! impl_check_fun {
 impl_check_fun!(is_atom, rustler_sys::enif_is_atom);
 impl_check_fun!(is_binary, rustler_sys::enif_is_binary);
 impl_check_fun!(is_empty_list, rustler_sys::enif_is_empty_list);
-impl_check_fun!(is_exception, rustler_sys::enif_is_exception);
 impl_check_fun!(is_fun, rustler_sys::enif_is_fun);
 impl_check_fun!(is_list, rustler_sys::enif_is_list);
 impl_check_fun!(is_map, rustler_sys::enif_is_map);
diff --git a/rustler_sys/src/rustler_sys_api.rs b/rustler_sys/src/rustler_sys_api.rs
index c7841a9e..ab15827b 100644
--- a/rustler_sys/src/rustler_sys_api.rs
+++ b/rustler_sys/src/rustler_sys_api.rs
@@ -307,6 +307,7 @@ pub enum ErlNifHash {
 }
 
 /// See [ErlNifTermType](http://www.erlang.org/doc/man/erl_nif.html#ErlNifTermType) in the Erlang docs.
+#[cfg(feature = "nif_version_2_15")]
 #[derive(Copy, Clone)]
 #[repr(C)]
 pub enum ErlNifTermType {