Use enif_get_double to implement is_float

rusterlium · Feb 12, 2024 · 176fc5c · 176fc5c
1 parent 81e2f30
commit 176fc5c
Showing 1 changed file with 5 additions and 34 deletions.
diff --git a/rustler/src/dynamic.rs b/rustler/src/dynamic.rs
@@ -1,3 +1,5 @@
+use std::ffi::c_double;
+
 #[cfg(feature = "nif_version_2_15")]
 use rustler_sys::ErlNifTermType;
 
@@ -104,40 +106,9 @@ impl<'a> Term<'a> {
     impl_check!(is_tuple);
 
     pub fn is_float(self) -> bool {
-        // Implementation derived from OTP's erl_nif.h, macro `is_float`. `is_number` already
-        // checks `is_float | is_integer`, so to distinguish these two, we check explicitly for
-        // float again.
-        const TAG_PRIMARY_MASK: usize = 0x3;
-        const TAG_PRIMARY_BOXED: usize = 0x2;
-        const TAG_PRIMARY_SIZE: usize = 2;
-        const TAG_PRIMARY_HEADER: usize = 0x0;
-        const TAG_PTR_MASK: usize = 0x7;
-        const FLOAT_SUBTAG: usize = 0x6 << TAG_PRIMARY_SIZE;
-        const TAG_HEADER_FLOAT: usize = TAG_PRIMARY_HEADER | FLOAT_SUBTAG;
-        const HEADER_ARITY_OFFSET: usize = 6;
-
-        const SIZE: usize = if cfg!(target_pointer_width = "64") {
-            // Also TAG_PTR_MASK 0x7
-            // TAG_LITERAL_PTR 0x4
-            1
-        } else {
-            2
-        };
-
-        const HEADER_FLONUM: usize = (SIZE << HEADER_ARITY_OFFSET) + TAG_HEADER_FLOAT;
-
-        let term_val = self.as_c_arg();
-        if term_val & TAG_PRIMARY_MASK == TAG_PRIMARY_BOXED {
-            dbg!(term_val);
-            let term_ptr = if cfg!(target_pointer_width = "64") {
-                term_val & !TAG_PTR_MASK
-            } else {
-                term_val - TAG_PRIMARY_BOXED
-            };
-            let header = unsafe { *(term_ptr as *const usize) };
-            header == HEADER_FLONUM
-        } else {
-            false
+        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
         }
     }