caret/
lib.rs

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1#![cfg_attr(docsrs, feature(doc_auto_cfg, doc_cfg))]
2#![doc = include_str!("../README.md")]
3// @@ begin lint list maintained by maint/add_warning @@
4#![allow(renamed_and_removed_lints)] // @@REMOVE_WHEN(ci_arti_stable)
5#![allow(unknown_lints)] // @@REMOVE_WHEN(ci_arti_nightly)
6#![warn(missing_docs)]
7#![warn(noop_method_call)]
8#![warn(unreachable_pub)]
9#![warn(clippy::all)]
10#![deny(clippy::await_holding_lock)]
11#![deny(clippy::cargo_common_metadata)]
12#![deny(clippy::cast_lossless)]
13#![deny(clippy::checked_conversions)]
14#![warn(clippy::cognitive_complexity)]
15#![deny(clippy::debug_assert_with_mut_call)]
16#![deny(clippy::exhaustive_enums)]
17#![deny(clippy::exhaustive_structs)]
18#![deny(clippy::expl_impl_clone_on_copy)]
19#![deny(clippy::fallible_impl_from)]
20#![deny(clippy::implicit_clone)]
21#![deny(clippy::large_stack_arrays)]
22#![warn(clippy::manual_ok_or)]
23#![deny(clippy::missing_docs_in_private_items)]
24#![warn(clippy::needless_borrow)]
25#![warn(clippy::needless_pass_by_value)]
26#![warn(clippy::option_option)]
27#![deny(clippy::print_stderr)]
28#![deny(clippy::print_stdout)]
29#![warn(clippy::rc_buffer)]
30#![deny(clippy::ref_option_ref)]
31#![warn(clippy::semicolon_if_nothing_returned)]
32#![warn(clippy::trait_duplication_in_bounds)]
33#![deny(clippy::unchecked_duration_subtraction)]
34#![deny(clippy::unnecessary_wraps)]
35#![warn(clippy::unseparated_literal_suffix)]
36#![deny(clippy::unwrap_used)]
37#![deny(clippy::mod_module_files)]
38#![allow(clippy::let_unit_value)] // This can reasonably be done for explicitness
39#![allow(clippy::uninlined_format_args)]
40#![allow(clippy::significant_drop_in_scrutinee)] // arti/-/merge_requests/588/#note_2812945
41#![allow(clippy::result_large_err)] // temporary workaround for arti#587
42#![allow(clippy::needless_raw_string_hashes)] // complained-about code is fine, often best
43#![allow(clippy::needless_lifetimes)] // See arti#1765
44//! <!-- @@ end lint list maintained by maint/add_warning @@ -->
45
46/// Declare an integer type with some named elements.
47///
48/// This macro declares a struct that wraps an integer
49/// type, and allows any integer type as a value.  Some values of this type
50/// have names, and others do not, but they are all allowed.
51///
52/// This macro is suitable for protocol implementations that accept
53/// any integer on the wire, and have definitions for some of those
54/// integers.  For example, Tor cell commands are 8-bit integers, but
55/// not every u8 is a currently recognized Tor command.
56///
57/// # Examples
58/// ```
59/// use caret::caret_int;
60/// caret_int! {
61///     pub struct FruitID(u8) {
62///         AVOCADO = 7,
63///         PERSIMMON = 8,
64///         LONGAN = 99
65///     }
66/// }
67///
68/// // Known fruits work the way we would expect...
69/// let a_num: u8 = FruitID::AVOCADO.into();
70/// assert_eq!(a_num, 7);
71/// let a_fruit: FruitID = 8.into();
72/// assert_eq!(a_fruit, FruitID::PERSIMMON);
73/// assert_eq!(format!("I'd like a {}", FruitID::PERSIMMON),
74///            "I'd like a PERSIMMON");
75///
76/// // And we can construct unknown fruits, if we encounter any.
77/// let weird_fruit: FruitID = 202.into();
78/// assert_eq!(format!("I'd like a {}", weird_fruit),
79///            "I'd like a 202");
80/// ```
81#[macro_export]
82macro_rules! caret_int {
83    {
84       $(#[$meta:meta])*
85       $v:vis struct $name:ident ( $numtype:ty ) {
86           $(
87               $(#[$item_meta:meta])*
88               $id:ident = $num:literal
89           ),*
90           $(,)?
91      }
92    } => {
93        #[derive(PartialEq,Eq,Copy,Clone)]
94        $(#[$meta])*
95        $v struct $name($numtype);
96
97        impl From<$name> for $numtype {
98            fn from(val: $name) -> $numtype { val.0 }
99        }
100        impl From<$numtype> for $name {
101            fn from(num: $numtype) -> $name { $name(num) }
102        }
103        impl $name {
104            $(
105                $( #[$item_meta] )*
106                pub const $id: $name = $name($num) ; )*
107            fn to_str(self) -> Option<&'static str> {
108                match self {
109                    $( $name::$id => Some(stringify!($id)), )*
110                    _ => None,
111                }
112            }
113            /// Return true if this value is one that we recognize.
114            $v fn is_recognized(self) -> bool {
115                match self {
116                    $( $name::$id  => true, )*
117                    _ => false
118                }
119            }
120            /// Try to convert this value from one of the recognized names.
121            $v fn from_name(name: &str) -> Option<Self> {
122                match name {
123                    $( stringify!($id) => Some($name::$id), )*
124                    _ => None
125                }
126            }
127            /// Return the underlying integer that this value represents.
128            fn get(self) -> $numtype {
129                self.into()
130            }
131        }
132        impl std::fmt::Display for $name {
133            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
134                match self.to_str() {
135                    Some(s) => write!(f, "{}", s),
136                    None => write!(f, "{}", self.0),
137                }
138            }
139        }
140        // `#[educe(Debug)]` could do this for us, but let's not deepen this macrology
141        impl std::fmt::Debug for $name {
142            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
143                write!(f, "{}({})", stringify!($name), self)
144            }
145        }
146    };
147
148}
caret/lib.rs

caret/
lib.rs
