otter-nif 0.3.1

Write Erlang NIFs in Rust. Direct mapping of the NIF C ABI with compile-time lifetime safety and no hidden magic.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68

//! [`Reference`] — unique Erlang references (`make_ref`), the canonical
//! one-shot token for tagging messages and replies.

use core::marker::PhantomData;

use crate::types::sealed::Sealed;
use crate::types::{Env, Invariant, RawTerm, Term};

/// An Erlang reference — a VM-unique token (`enif_make_ref`), commonly used to
/// tag a request so its reply can be matched.
#[derive(Clone, Copy)]
pub struct Reference<'id> {
    raw_term: RawTerm,
    _id: Invariant<'id>,
}

impl<'id> Reference<'id> {
    #[crate::raw]
    pub(crate) fn from_raw(raw_term: RawTerm) -> Self {
        Self { raw_term, _id: PhantomData }
    }

    /// Create a new unique reference (`enif_make_ref`).
    pub fn new(env: impl Env<'id>) -> Self {
        let raw_term = unsafe { enif_ffi::make_ref(env.raw_env()) };
        Reference { raw_term, _id: PhantomData }
    }

    /// Returns `true` if `term` is a reference (`enif_is_ref`).
    pub fn is_ref(env: impl Env<'id>, term: impl Term<'id>) -> bool {
        unsafe { enif_ffi::is_ref(env.raw_env(), term.raw_term()) != 0 }
    }
}

impl<'id> Sealed for Reference<'id> {}

impl<'id> Term<'id> for Reference<'id> {
    fn raw_term(self) -> RawTerm {
        self.raw_term
    }
}

impl PartialEq for Reference<'_> {
    fn eq(&self, other: &Self) -> bool {
        unsafe { enif_ffi::is_identical(self.raw_term, other.raw_term) != 0 }
    }
}

impl Eq for Reference<'_> {}

impl PartialOrd for Reference<'_> {
    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
        Some(self.cmp(other))
    }
}

impl Ord for Reference<'_> {
    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
        let c = unsafe { enif_ffi::compare(self.raw_term, other.raw_term) };
        c.cmp(&0)
    }
}

impl std::fmt::Debug for Reference<'_> {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "Reference")
    }
}