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    /// Bytes as they are.
36    Bytes(&'a [u8]),
37}
38
39/// A borrowed map: entries in file order.
40#[derive(Debug, Clone, Copy, PartialEq, Default)]
41pub struct MapRef<'a>(pub &'a [(&'a str, ValueRef<'a>)]);
42
43impl<'a> MapRef<'a> {
44    pub fn get(&self, key: &str) -> Option<&'a ValueRef<'a>> {
45        self.0.iter().find(|(k, _)| *k == key).map(|(_, v)| v)
46    }
47
48    pub fn iter(&self) -> impl ExactSizeIterator<Item = (&'a str, &'a ValueRef<'a>)> + 'a {
49        self.0.iter().map(|(k, v)| (*k, v))
50    }
51
52    pub fn keys(&self) -> impl ExactSizeIterator<Item = &'a str> + 'a {
53        self.0.iter().map(|(k, _)| *k)
54    }
55
56    pub fn len(&self) -> usize {
57        self.0.len()
58    }
59
60    pub fn is_empty(&self) -> bool {
61        self.0.is_empty()
62    }
63}
64
65impl<'a> ValueRef<'a> {
66    /// The type's name, for messages: `"a string"`, `"a list"`, ...
67    pub fn kind_name(&self) -> &'static str {
68        match self {
69            ValueRef::Null => "null",
70            ValueRef::Bool(_) => "true/false",
71            ValueRef::Int(_) => "an integer",
72            ValueRef::Float(_) => "a number",
73            ValueRef::Str(_) => "a string",
74            ValueRef::List(_) => "a list",
75            ValueRef::Map(_) => "an object",
76            ValueRef::Ref { .. } => "a reference",
77            ValueRef::Tag { .. } => "a tag",
78            ValueRef::Res { .. } => "a resource",
79            ValueRef::Lang(_) => "a translation key",
80            ValueRef::Text(_) => "a text",
81            ValueRef::Image(_) => "an image",
82            ValueRef::Color(_) => "a color",
83            ValueRef::Bytes(_) => "bytes",
84        }
85    }
86
87    pub fn is_null(&self) -> bool {
88        matches!(self, ValueRef::Null)
89    }
90
91    pub fn as_bool(&self) -> Option<bool> {
92        match self {
93            ValueRef::Bool(b) => Some(*b),
94            _ => None,
95        }
96    }
97
98    pub fn as_i64(&self) -> Option<i64> {
99        match self {
100            ValueRef::Int(n) => Some(*n),
101            ValueRef::Float(f) if f.fract() == 0.0 && f.abs() < 9.0e15 => Some(*f as i64),
102            _ => None,
103        }
104    }
105
106    pub fn as_f64(&self) -> Option<f64> {
107        match self {
108            ValueRef::Int(n) => Some(*n as f64),
109            ValueRef::Float(f) => Some(*f),
110            _ => None,
111        }
112    }
113
114    /// The string of a `Str` (and of the string-like typed values: `Text`, `Image`).
115    pub fn as_str(&self) -> Option<&'a str> {
116        match self {
117            ValueRef::Str(s) | ValueRef::Text(s) | ValueRef::Image(s) => Some(s),
118            _ => None,
119        }
120    }
121
122    pub fn as_list(&self) -> Option<&'a [ValueRef<'a>]> {
123        match self {
124            ValueRef::List(l) => Some(l),
125            _ => None,
126        }
127    }
128
129    pub fn as_map(&self) -> Option<MapRef<'a>> {
130        match self {
131            ValueRef::Map(m) => Some(*m),
132            _ => None,
133        }
134    }
135
136    /// `self[key]` of a map, `None` for anything else.
137    pub fn get(&self, key: &str) -> Option<&'a ValueRef<'a>> {
138        self.as_map()?.get(key)
139    }
140
141    /// An owned copy.
142    pub fn to_value(&self) -> Value {
143        match *self {
144            ValueRef::Null => Value::Null,
145            ValueRef::Bool(b) => Value::Bool(b),
146            ValueRef::Int(n) => Value::Int(n),
147            ValueRef::Float(f) => Value::Float(f),
148            ValueRef::Str(s) => Value::Str(s.to_string()),
149            ValueRef::List(l) => Value::List(l.iter().map(ValueRef::to_value).collect()),
150            ValueRef::Map(m) => {
151                let mut out = Map::with_capacity(m.len());
152                for (k, v) in m.iter() {
153                    out.insert(k, v.to_value());
154                }
155                Value::Map(out)
156            }
157            ValueRef::Ref { kind, id } => Value::Ref(Ref::new(kind, id)),
158            ValueRef::Tag { kind, id } => Value::Tag(Ref::new(kind, id)),
159            ValueRef::Res { set, key } => Value::Res(Res { set: set.to_string(), key: key.to_string() }),
160            ValueRef::Lang(k) => Value::Lang(k.to_string()),
161            ValueRef::Text(s) => Value::Text(s.to_string()),
162            ValueRef::Image(s) => Value::Image(s.to_string()),
163            ValueRef::Color(c) => Value::Color(c),
164            ValueRef::Bytes(b) => Value::Bytes(b.to_vec()),
165        }
166    }
167
168    /// The reference of a `Ref`, owned.
169    pub fn to_ref(&self) -> Option<Ref> {
170        match *self {
171            ValueRef::Ref { kind, id } => Some(Ref::new(kind, id)),
172            _ => None,
173        }
174    }
175}
176
177impl Value {
178    /// This value, borrowed (lists and maps in `arena`) — what schemas read.
179    pub fn borrow<'a>(&'a self, arena: &'a Bump) -> ValueRef<'a> {
180        match self {
181            Value::Null => ValueRef::Null,
182            Value::Bool(b) => ValueRef::Bool(*b),
183            Value::Int(n) => ValueRef::Int(*n),
184            Value::Float(f) => ValueRef::Float(*f),
185            Value::Str(s) => ValueRef::Str(s),
186            Value::List(l) => ValueRef::List(arena.alloc_slice_fill_iter(l.iter().map(|v| v.borrow(arena)))),
187            Value::Map(m) => ValueRef::Map(MapRef(arena.alloc_slice_fill_iter(m.iter().map(|(k, v)| (k, v.borrow(arena)))))),
188            Value::Ref(r) => ValueRef::Ref { kind: &r.kind, id: &r.id },
189            Value::Tag(r) => ValueRef::Tag { kind: &r.kind, id: &r.id },
190            Value::Res(r) => ValueRef::Res { set: &r.set, key: &r.key },
191            Value::Lang(k) => ValueRef::Lang(k),
192            Value::Text(s) => ValueRef::Text(s),
193            Value::Image(s) => ValueRef::Image(s),
194            Value::Color(c) => ValueRef::Color(*c),
195            Value::Bytes(b) => ValueRef::Bytes(b),
196        }
197    }
198}
yog_data/borrowed.rs

yog_data/
borrowed.rs
