enum_ordinalize_derive/
panic.rs

1use core::fmt::{self, Display, Formatter};
2
3use proc_macro2::Span;
4use syn::Ident;
5
6struct DisplayStringSlice<'a>(&'a [&'static str]);
7
8impl<'a> Display for DisplayStringSlice<'a> {
9    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
10        for &s in self.0 {
11            f.write_str("\n    ")?;
12            f.write_str(s)?;
13        }
14
15        Ok(())
16    }
17}
18
19#[inline]
20pub(crate) fn not_enum(span: Span) -> syn::Error {
21    syn::Error::new(span, "only enums can be ordinalized")
22}
23
24#[inline]
25pub(crate) fn no_variant(span: Span) -> syn::Error {
26    syn::Error::new(span, "an ordinalized enum needs to have at least one variant")
27}
28
29#[inline]
30pub(crate) fn not_unit_variant(span: Span) -> syn::Error {
31    syn::Error::new(span, "an ordinalized enum can only have unit variants")
32}
33
34#[inline]
35pub(crate) fn unsupported_discriminant(span: Span) -> syn::Error {
36    syn::Error::new(
37        span,
38        "the discriminant of a variant of an ordinalized enum needs to be a legal literal \
39         integer, a constant variable/function or a constant expression",
40    )
41}
42#[inline]
43pub(crate) fn constant_variable_on_non_determined_size_enum(span: Span) -> syn::Error {
44    syn::Error::new(
45        span,
46        "the discriminant of a variant can be assigned not to a literal integer only when the \
47         ordinalized enum is using the `repr` attribute to determine it's size before compilation",
48    )
49}
50
51#[inline]
52pub fn list_attribute_usage(name: &Ident, span: Span) -> syn::Error {
53    syn::Error::new(span, format!("the `{name}` attribute should be a list"))
54    // use `name = name` to support Rust 1.56
55}
56
57#[inline]
58pub(crate) fn bool_attribute_usage(name: &Ident, span: Span) -> syn::Error {
59    syn::Error::new(
60        span,
61        format!("the `{name}` attribute should be a name-value pair. The value type is boolean"),
62    )
63    // use `name = name` to support Rust 1.56
64}
65
66#[inline]
67pub(crate) fn sub_attributes_for_ordinalize(span: Span) -> syn::Error {
68    syn::Error::new(
69        span,
70        format!(
71            "available sub-attributes for the `ordinalize` attribute:{}",
72            DisplayStringSlice(&[
73                "impl_trait",
74                "variant_count",
75                "variants",
76                "values",
77                "ordinal",
78                "from_ordinal_unsafe",
79                "from_ordinal",
80            ])
81        ),
82    )
83}
enum_ordinalize_derive/panic.rs

enum_ordinalize_derive/
panic.rs
