const_format/
msg.rs

1#![allow(non_camel_case_types)]
2
3use crate::fmt::{Error, StrWriter};
4
5use core::marker::PhantomData;
6
7macro_rules! type_level_error {
8    (
9        arguments($($args:tt)*)
10
11        $($error:ident => $error_ty:ident<$($error_param:ident),*> ,)*
12    ) => {
13        type_level_error!{
14            @inner
15            arguments($($args)*)
16
17            Result::Ok(()), Ok => Ok<>,
18            $(
19                Result::Err(Error::$error), $error => $error_ty<$($error_param),*>,
20            )*
21        }
22    };
23    (@inner
24        arguments($cap:ident)
25
26        $($matched:pat , $error:ident => $error_ty:ident<$($error_param:ident),*> ,)*
27    ) => {
28
29        enum ErrorKind {
30            $($error,)*
31        }
32
33        impl ErrorTuple {
34            pub const EMPTY: ErrorTuple = ErrorTuple{
35                error_variant: ErrorKind::Ok as usize,
36                capacity: 0,
37            };
38
39            pub const fn new(opt: Result<(), Error>, writer: &StrWriter) -> Self{
40                let variant = match opt {
41                    $($matched => ErrorKind::$error as usize,)*
42                };
43
44                Self{
45                    error_variant: variant,
46                    capacity: writer.capacity(),
47                }
48            }
49
50        }
51
52
53        $(
54            pub struct $error_ty<$($error_param,)*>(PhantomData<($($error_param,)*)>);
55
56            impl<$($error_param,)*> $error_ty<$($error_param,)*> {
57                pub const NEW: Self = Self(PhantomData);
58            }
59
60            impl<$cap> ErrorAsType for ErrorPicker<[(); ErrorKind::$error as usize], $cap> {
61                type Type = $error_ty<$($error_param,)*>;
62            }
63        )*
64    }
65}
66
67pub struct ErrorTupleAndStrWriter<A> {
68    pub error: ErrorTuple,
69    pub writer: StrWriter<A>,
70}
71
72pub struct ErrorPicker<E, Cap>(PhantomData<fn() -> (E, Cap)>);
73
74pub struct ErrorTuple {
75    pub error_variant: usize,
76    pub capacity: usize,
77}
78
79pub trait ErrorAsType {
80    type Type;
81}
82
83type_level_error! {
84    arguments(cap)
85
86    NotEnoughSpace => not_enough_space_to_write_text_in_StrWriter_with_this_capacity<cap>,
87
88    NotAscii => input_text_was_not_ascii<>,
89
90    NotOnCharBoundary => NotOnCharBoundary<>,
91}
const_format/msg.rs

const_format/
msg.rs
