time/format_description/
owned_format_item.rs

1//! A format item with owned data.
2
3use alloc::boxed::Box;
4use alloc::string::String;
5use alloc::vec::Vec;
6use core::fmt;
7
8use crate::error;
9use crate::format_description::{BorrowedFormatItem, Component};
10
11/// A complete description of how to format and parse a type.
12#[non_exhaustive]
13#[derive(Clone, PartialEq, Eq)]
14pub enum OwnedFormatItem {
15    /// Bytes that are formatted as-is.
16    ///
17    /// **Note**: These bytes **should** be UTF-8, but are not required to be. The value is passed
18    /// through `String::from_utf8_lossy` when necessary.
19    Literal(Box<[u8]>),
20    /// A minimal representation of a single non-literal item.
21    Component(Component),
22    /// A series of literals or components that collectively form a partial or complete
23    /// description.
24    Compound(Box<[Self]>),
25    /// A `FormatItem` that may or may not be present when parsing. If parsing fails, there
26    /// will be no effect on the resulting `struct`.
27    ///
28    /// This variant has no effect on formatting, as the value is guaranteed to be present.
29    Optional(Box<Self>),
30    /// A series of `FormatItem`s where, when parsing, the first successful parse is used. When
31    /// formatting, the first element of the [`Vec`] is used. An empty [`Vec`] is a no-op when
32    /// formatting or parsing.
33    First(Box<[Self]>),
34}
35
36impl fmt::Debug for OwnedFormatItem {
37    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
38        match self {
39            Self::Literal(literal) => f.write_str(&String::from_utf8_lossy(literal)),
40            Self::Component(component) => component.fmt(f),
41            Self::Compound(compound) => compound.fmt(f),
42            Self::Optional(item) => f.debug_tuple("Optional").field(item).finish(),
43            Self::First(items) => f.debug_tuple("First").field(items).finish(),
44        }
45    }
46}
47
48// region: conversions from FormatItem
49impl From<BorrowedFormatItem<'_>> for OwnedFormatItem {
50    fn from(item: BorrowedFormatItem<'_>) -> Self {
51        (&item).into()
52    }
53}
54
55impl From<&BorrowedFormatItem<'_>> for OwnedFormatItem {
56    fn from(item: &BorrowedFormatItem<'_>) -> Self {
57        match item {
58            BorrowedFormatItem::Literal(literal) => {
59                Self::Literal(literal.to_vec().into_boxed_slice())
60            }
61            BorrowedFormatItem::Component(component) => Self::Component(*component),
62            BorrowedFormatItem::Compound(compound) => Self::Compound(
63                compound
64                    .iter()
65                    .cloned()
66                    .map(Into::into)
67                    .collect::<Vec<_>>()
68                    .into_boxed_slice(),
69            ),
70            BorrowedFormatItem::Optional(item) => Self::Optional(Box::new((*item).into())),
71            BorrowedFormatItem::First(items) => Self::First(
72                items
73                    .iter()
74                    .cloned()
75                    .map(Into::into)
76                    .collect::<Vec<_>>()
77                    .into_boxed_slice(),
78            ),
79        }
80    }
81}
82
83impl From<Vec<BorrowedFormatItem<'_>>> for OwnedFormatItem {
84    fn from(items: Vec<BorrowedFormatItem<'_>>) -> Self {
85        items.as_slice().into()
86    }
87}
88
89impl<'a, T: AsRef<[BorrowedFormatItem<'a>]> + ?Sized> From<&T> for OwnedFormatItem {
90    fn from(items: &T) -> Self {
91        Self::Compound(
92            items
93                .as_ref()
94                .iter()
95                .cloned()
96                .map(Into::into)
97                .collect::<Vec<_>>()
98                .into_boxed_slice(),
99        )
100    }
101}
102// endregion conversions from FormatItem
103
104// region: from variants
105impl From<Component> for OwnedFormatItem {
106    fn from(component: Component) -> Self {
107        Self::Component(component)
108    }
109}
110
111impl TryFrom<OwnedFormatItem> for Component {
112    type Error = error::DifferentVariant;
113
114    fn try_from(value: OwnedFormatItem) -> Result<Self, Self::Error> {
115        match value {
116            OwnedFormatItem::Component(component) => Ok(component),
117            _ => Err(error::DifferentVariant),
118        }
119    }
120}
121
122impl From<Vec<Self>> for OwnedFormatItem {
123    fn from(items: Vec<Self>) -> Self {
124        Self::Compound(items.into_boxed_slice())
125    }
126}
127
128impl TryFrom<OwnedFormatItem> for Vec<OwnedFormatItem> {
129    type Error = error::DifferentVariant;
130
131    fn try_from(value: OwnedFormatItem) -> Result<Self, Self::Error> {
132        match value {
133            OwnedFormatItem::Compound(items) => Ok(items.into_vec()),
134            _ => Err(error::DifferentVariant),
135        }
136    }
137}
138// endregion from variants
139
140// region: equality
141impl PartialEq<Component> for OwnedFormatItem {
142    fn eq(&self, rhs: &Component) -> bool {
143        matches!(self, Self::Component(component) if component == rhs)
144    }
145}
146
147impl PartialEq<OwnedFormatItem> for Component {
148    fn eq(&self, rhs: &OwnedFormatItem) -> bool {
149        rhs == self
150    }
151}
152
153impl PartialEq<&[Self]> for OwnedFormatItem {
154    fn eq(&self, rhs: &&[Self]) -> bool {
155        matches!(self, Self::Compound(compound) if &&**compound == rhs)
156    }
157}
158
159impl PartialEq<OwnedFormatItem> for &[OwnedFormatItem] {
160    fn eq(&self, rhs: &OwnedFormatItem) -> bool {
161        rhs == self
162    }
163}
164// endregion equality
time/format_description/owned_format_item.rs

time/format_description/
owned_format_item.rs
