yog_data/
borrowed.rs

1//! [`ValueRef`]: a value borrowed from where it was read — what schemas
2//! read. Decoded from the binary form ([`crate::binary::decode_ref`]) no
3//! string is copied: every one points into the bytes, and lists and maps
4//! are slices in an arena ([`Bump`]). An owned [`Value`] lends itself the
5//! same way ([`Value::borrow`]).
6
7use bumpalo::Bump;
8
9use crate::value::{Map, Ref, Res, Value};
10
11/// A borrowed [`Value`]: the same cases, strings `&'a str`, lists and maps slices.
12#[derive(Debug, Clone, Copy, PartialEq)]
13pub enum ValueRef<'a> {
14    Null,
15    Bool(bool),
16    Int(i64),
17    Float(f64),
18    Str(&'a str),
19    List(&'a [ValueRef<'a>]),
20    Map(MapRef<'a>),
21    /// `@item:minecraft:stick`.
22    Ref { kind: &'a str, id: &'a str },
23    /// `@tag:item:minecraft:planks`.
24    Tag { kind: &'a str, id: &'a str },
25    /// `@Strings.title`.
26    Res { set: &'a str, key: &'a str },
27    /// `@lang:gui.done`.
28    Lang(&'a str),
29    /// Yog text.
30    Text(&'a str),
31    /// An image source.
32    Image(&'a str),
33    /// `0xAARRGGBB`.
34    Color(u32),
35}
36
37/// A borrowed map: entries in file order.
38#[derive(Debug, Clone, Copy, PartialEq, Default)]
39pub struct MapRef<'a>(pub &'a [(&'a str, ValueRef<'a>)]);
40
41impl<'a> MapRef<'a> {
42    pub fn get(&self, key: &str) -> Option<&'a ValueRef<'a>> {
43        self.0.iter().find(|(k, _)| *k == key).map(|(_, v)| v)
44    }
45
46    pub fn iter(&self) -> impl ExactSizeIterator<Item = (&'a str, &'a ValueRef<'a>)> + 'a {
47        self.0.iter().map(|(k, v)| (*k, v))
48    }
49
50    pub fn keys(&self) -> impl ExactSizeIterator<Item = &'a str> + 'a {
51        self.0.iter().map(|(k, _)| *k)
52    }
53
54    pub fn len(&self) -> usize {
55        self.0.len()
56    }
57
58    pub fn is_empty(&self) -> bool {
59        self.0.is_empty()
60    }
61}
62
63impl<'a> ValueRef<'a> {
64    /// The type's name, for messages: `"a string"`, `"a list"`, ...
65    pub fn kind_name(&self) -> &'static str {
66        match self {
67            ValueRef::Null => "null",
68            ValueRef::Bool(_) => "true/false",
69            ValueRef::Int(_) => "an integer",
70            ValueRef::Float(_) => "a number",
71            ValueRef::Str(_) => "a string",
72            ValueRef::List(_) => "a list",
73            ValueRef::Map(_) => "an object",
74            ValueRef::Ref { .. } => "a reference",
75            ValueRef::Tag { .. } => "a tag",
76            ValueRef::Res { .. } => "a resource",
77            ValueRef::Lang(_) => "a translation key",
78            ValueRef::Text(_) => "a text",
79            ValueRef::Image(_) => "an image",
80            ValueRef::Color(_) => "a color",
81        }
82    }
83
84    pub fn is_null(&self) -> bool {
85        matches!(self, ValueRef::Null)
86    }
87
88    pub fn as_bool(&self) -> Option<bool> {
89        match self {
90            ValueRef::Bool(b) => Some(*b),
91            _ => None,
92        }
93    }
94
95    pub fn as_i64(&self) -> Option<i64> {
96        match self {
97            ValueRef::Int(n) => Some(*n),
98            ValueRef::Float(f) if f.fract() == 0.0 && f.abs() < 9.0e15 => Some(*f as i64),
99            _ => None,
100        }
101    }
102
103    pub fn as_f64(&self) -> Option<f64> {
104        match self {
105            ValueRef::Int(n) => Some(*n as f64),
106            ValueRef::Float(f) => Some(*f),
107            _ => None,
108        }
109    }
110
111    /// The string of a `Str` (and of the string-like typed values: `Text`, `Image`).
112    pub fn as_str(&self) -> Option<&'a str> {
113        match self {
114            ValueRef::Str(s) | ValueRef::Text(s) | ValueRef::Image(s) => Some(s),
115            _ => None,
116        }
117    }
118
119    pub fn as_list(&self) -> Option<&'a [ValueRef<'a>]> {
120        match self {
121            ValueRef::List(l) => Some(l),
122            _ => None,
123        }
124    }
125
126    pub fn as_map(&self) -> Option<MapRef<'a>> {
127        match self {
128            ValueRef::Map(m) => Some(*m),
129            _ => None,
130        }
131    }
132
133    /// `self[key]` of a map, `None` for anything else.
134    pub fn get(&self, key: &str) -> Option<&'a ValueRef<'a>> {
135        self.as_map()?.get(key)
136    }
137
138    /// An owned copy.
139    pub fn to_value(&self) -> Value {
140        match *self {
141            ValueRef::Null => Value::Null,
142            ValueRef::Bool(b) => Value::Bool(b),
143            ValueRef::Int(n) => Value::Int(n),
144            ValueRef::Float(f) => Value::Float(f),
145            ValueRef::Str(s) => Value::Str(s.to_string()),
146            ValueRef::List(l) => Value::List(l.iter().map(ValueRef::to_value).collect()),
147            ValueRef::Map(m) => {
148                let mut out = Map::with_capacity(m.len());
149                for (k, v) in m.iter() {
150                    out.insert(k, v.to_value());
151                }
152                Value::Map(out)
153            }
154            ValueRef::Ref { kind, id } => Value::Ref(Ref::new(kind, id)),
155            ValueRef::Tag { kind, id } => Value::Tag(Ref::new(kind, id)),
156            ValueRef::Res { set, key } => Value::Res(Res { set: set.to_string(), key: key.to_string() }),
157            ValueRef::Lang(k) => Value::Lang(k.to_string()),
158            ValueRef::Text(s) => Value::Text(s.to_string()),
159            ValueRef::Image(s) => Value::Image(s.to_string()),
160            ValueRef::Color(c) => Value::Color(c),
161        }
162    }
163
164    /// The reference of a `Ref`, owned.
165    pub fn to_ref(&self) -> Option<Ref> {
166        match *self {
167            ValueRef::Ref { kind, id } => Some(Ref::new(kind, id)),
168            _ => None,
169        }
170    }
171}
172
173impl Value {
174    /// This value, borrowed (lists and maps in `arena`) — what schemas read.
175    pub fn borrow<'a>(&'a self, arena: &'a Bump) -> ValueRef<'a> {
176        match self {
177            Value::Null => ValueRef::Null,
178            Value::Bool(b) => ValueRef::Bool(*b),
179            Value::Int(n) => ValueRef::Int(*n),
180            Value::Float(f) => ValueRef::Float(*f),
181            Value::Str(s) => ValueRef::Str(s),
182            Value::List(l) => ValueRef::List(arena.alloc_slice_fill_iter(l.iter().map(|v| v.borrow(arena)))),
183            Value::Map(m) => ValueRef::Map(MapRef(arena.alloc_slice_fill_iter(m.iter().map(|(k, v)| (k, v.borrow(arena)))))),
184            Value::Ref(r) => ValueRef::Ref { kind: &r.kind, id: &r.id },
185            Value::Tag(r) => ValueRef::Tag { kind: &r.kind, id: &r.id },
186            Value::Res(r) => ValueRef::Res { set: &r.set, key: &r.key },
187            Value::Lang(k) => ValueRef::Lang(k),
188            Value::Text(s) => ValueRef::Text(s),
189            Value::Image(s) => ValueRef::Image(s),
190            Value::Color(c) => ValueRef::Color(*c),
191        }
192    }
193}
yog_data/borrowed.rs

yog_data/
borrowed.rs
