yog_data/
value.rs

1//! The model: a tree of typed values, like NBT.
2
3use std::fmt;
4
5/// A Yog Data value.
6///
7/// The text form has no syntax of its own for the typed values (`Ref`,
8/// `Tag`, `Res`, `Text`, `Image`, `Color`): they're written as strings
9/// (`"@item:minecraft:stick"`), so every file stays JSON, and the schema of
10/// a field says which type its string is. The binary form keeps the type.
11#[derive(Debug, Clone, PartialEq, Default)]
12pub enum Value {
13    #[default]
14    Null,
15    Bool(bool),
16    Int(i64),
17    Float(f64),
18    Str(String),
19    List(Vec<Value>),
20    Map(Map),
21    /// `@item:minecraft:stick` — content of some kind, by id.
22    Ref(Ref),
23    /// `@tag:item:minecraft:planks` — a tag of content of some kind.
24    Tag(Ref),
25    /// `@Strings.title` — a mod resource (`.yres` entry).
26    Res(Res),
27    /// `@lang:gui.done` — a translation key of the game's or a mod's lang files.
28    Lang(String),
29    /// Yog text: `{b|bold} and {#8d6acc|color}`.
30    Text(String),
31    /// An image source: `sprite:button`, `mymod:gui/logo`, `item:minecraft:stick`.
32    Image(String),
33    /// `0xAARRGGBB`.
34    Color(u32),
35}
36
37/// A reference to content: its kind (`item`, `block`, `entity`, `recipe`,
38/// `entry`, `category`, or a mod's own) and id (`minecraft:stick`,
39/// `minecraft:furnace[facing=north]`).
40#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
41pub struct Ref {
42    pub kind: String,
43    pub id: String,
44}
45
46impl Ref {
47    pub fn new(kind: impl Into<String>, id: impl Into<String>) -> Self {
48        Self {
49            kind: kind.into(),
50            id: id.into(),
51        }
52    }
53
54    /// The namespace of the id (`minecraft` for an id without one).
55    pub fn namespace(&self) -> &str {
56        self.id.split_once(':').map_or("minecraft", |(ns, _)| ns)
57    }
58}
59
60/// A mod resource: `@<set>.<key>` — `@Strings.screen.title` is set
61/// `Strings`, key `screen.title`.
62#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
63pub struct Res {
64    pub set: String,
65    pub key: String,
66}
67
68/// A map: entries in file order, keys unique.
69#[derive(Debug, Clone, PartialEq, Default)]
70pub struct Map(Vec<(String, Value)>);
71
72impl Map {
73    pub fn new() -> Self {
74        Self(Vec::new())
75    }
76
77    pub fn with_capacity(n: usize) -> Self {
78        Self(Vec::with_capacity(n))
79    }
80
81    pub fn get(&self, key: &str) -> Option<&Value> {
82        self.0.iter().find(|(k, _)| k == key).map(|(_, v)| v)
83    }
84
85    pub fn get_mut(&mut self, key: &str) -> Option<&mut Value> {
86        self.0.iter_mut().find(|(k, _)| k == key).map(|(_, v)| v)
87    }
88
89    /// The value of the `i`-th entry.
90    pub fn value_at(&self, i: usize) -> Option<&Value> {
91        self.0.get(i).map(|(_, v)| v)
92    }
93
94    /// The position of `key` among the entries.
95    pub fn index_of(&self, key: &str) -> Option<usize> {
96        self.0.iter().position(|(k, _)| k == key)
97    }
98
99    /// Sets `key`, in place if it's there, else at the end; returns the old value.
100    pub fn insert(&mut self, key: impl Into<String>, value: Value) -> Option<Value> {
101        let key = key.into();
102        match self.get_mut(&key) {
103            Some(slot) => Some(std::mem::replace(slot, value)),
104            None => {
105                self.0.push((key, value));
106                None
107            }
108        }
109    }
110
111    /// Appends without checking for the key — for decoders that already did.
112    pub(crate) fn push_unchecked(&mut self, key: String, value: Value) {
113        self.0.push((key, value));
114    }
115
116    pub fn remove(&mut self, key: &str) -> Option<Value> {
117        let i = self.index_of(key)?;
118        Some(self.0.remove(i).1)
119    }
120
121    pub fn len(&self) -> usize {
122        self.0.len()
123    }
124
125    pub fn is_empty(&self) -> bool {
126        self.0.is_empty()
127    }
128
129    pub fn iter(&self) -> impl ExactSizeIterator<Item = (&str, &Value)> {
130        self.0.iter().map(|(k, v)| (k.as_str(), v))
131    }
132
133    pub fn keys(&self) -> impl ExactSizeIterator<Item = &str> {
134        self.0.iter().map(|(k, _)| k.as_str())
135    }
136
137    pub fn retain(&mut self, mut keep: impl FnMut(&str, &Value) -> bool) {
138        self.0.retain(|(k, v)| keep(k, v));
139    }
140}
141
142impl IntoIterator for Map {
143    type Item = (String, Value);
144    type IntoIter = std::vec::IntoIter<(String, Value)>;
145    fn into_iter(self) -> Self::IntoIter {
146        self.0.into_iter()
147    }
148}
149
150impl<K: Into<String>> FromIterator<(K, Value)> for Map {
151    fn from_iter<I: IntoIterator<Item = (K, Value)>>(iter: I) -> Self {
152        let mut map = Map::new();
153        for (k, v) in iter {
154            map.insert(k, v);
155        }
156        map
157    }
158}
159
160impl Value {
161    /// The type's name, for messages: `"a string"`, `"a list"`, ...
162    pub fn kind_name(&self) -> &'static str {
163        match self {
164            Value::Null => "null",
165            Value::Bool(_) => "true/false",
166            Value::Int(_) => "an integer",
167            Value::Float(_) => "a number",
168            Value::Str(_) => "a string",
169            Value::List(_) => "a list",
170            Value::Map(_) => "an object",
171            Value::Ref(_) => "a reference",
172            Value::Tag(_) => "a tag",
173            Value::Res(_) => "a resource",
174            Value::Lang(_) => "a translation key",
175            Value::Text(_) => "a text",
176            Value::Image(_) => "an image",
177            Value::Color(_) => "a color",
178        }
179    }
180
181    pub fn is_null(&self) -> bool {
182        matches!(self, Value::Null)
183    }
184
185    pub fn as_bool(&self) -> Option<bool> {
186        match self {
187            Value::Bool(b) => Some(*b),
188            _ => None,
189        }
190    }
191
192    pub fn as_i64(&self) -> Option<i64> {
193        match self {
194            Value::Int(n) => Some(*n),
195            Value::Float(f) if f.fract() == 0.0 && f.abs() < 9.0e15 => Some(*f as i64),
196            _ => None,
197        }
198    }
199
200    pub fn as_f64(&self) -> Option<f64> {
201        match self {
202            Value::Int(n) => Some(*n as f64),
203            Value::Float(f) => Some(*f),
204            _ => None,
205        }
206    }
207
208    /// The string of a `Str` (and of the string-like typed values: `Text`, `Image`).
209    pub fn as_str(&self) -> Option<&str> {
210        match self {
211            Value::Str(s) | Value::Text(s) | Value::Image(s) => Some(s),
212            _ => None,
213        }
214    }
215
216    pub fn as_list(&self) -> Option<&[Value]> {
217        match self {
218            Value::List(l) => Some(l),
219            _ => None,
220        }
221    }
222
223    pub fn as_map(&self) -> Option<&Map> {
224        match self {
225            Value::Map(m) => Some(m),
226            _ => None,
227        }
228    }
229
230    /// `self[key]` of a map, `None` for anything else.
231    pub fn get(&self, key: &str) -> Option<&Value> {
232        self.as_map()?.get(key)
233    }
234
235    /// The value at `path`.
236    pub fn at(&self, path: &Path) -> Option<&Value> {
237        let mut v = self;
238        for seg in path.segments() {
239            v = match (seg, v) {
240                (Seg::Key(k), Value::Map(m)) => m.get(k)?,
241                (Seg::Index(i), Value::List(l)) => l.get(*i)?,
242                _ => return None,
243            };
244        }
245        Some(v)
246    }
247}
248
249impl From<bool> for Value {
250    fn from(b: bool) -> Self {
251        Value::Bool(b)
252    }
253}
254impl From<i64> for Value {
255    fn from(n: i64) -> Self {
256        Value::Int(n)
257    }
258}
259impl From<f64> for Value {
260    fn from(f: f64) -> Self {
261        Value::Float(f)
262    }
263}
264impl From<&str> for Value {
265    fn from(s: &str) -> Self {
266        Value::Str(s.to_string())
267    }
268}
269impl From<String> for Value {
270    fn from(s: String) -> Self {
271        Value::Str(s)
272    }
273}
274impl From<Vec<Value>> for Value {
275    fn from(l: Vec<Value>) -> Self {
276        Value::List(l)
277    }
278}
279impl From<Map> for Value {
280    fn from(m: Map) -> Self {
281        Value::Map(m)
282    }
283}
284
285/// One step of a [`Path`].
286#[derive(Debug, Clone, PartialEq, Eq, Hash)]
287pub enum Seg {
288    Key(String),
289    Index(usize),
290}
291
292/// Where a value is in a document: `entries[2].pages[0].item`.
293#[derive(Debug, Clone, PartialEq, Eq, Hash, Default)]
294pub struct Path(Vec<Seg>);
295
296impl Path {
297    pub fn root() -> Self {
298        Self(Vec::new())
299    }
300
301    pub fn segments(&self) -> &[Seg] {
302        &self.0
303    }
304
305    pub fn is_root(&self) -> bool {
306        self.0.is_empty()
307    }
308
309    pub fn push(&mut self, seg: Seg) {
310        self.0.push(seg);
311    }
312
313    pub fn pop(&mut self) {
314        self.0.pop();
315    }
316
317    pub fn key(&self, key: &str) -> Path {
318        let mut p = self.clone();
319        p.0.push(Seg::Key(key.to_string()));
320        p
321    }
322
323    pub fn index(&self, i: usize) -> Path {
324        let mut p = self.clone();
325        p.0.push(Seg::Index(i));
326        p
327    }
328}
329
330impl fmt::Display for Path {
331    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
332        if self.0.is_empty() {
333            return f.write_str("(root)");
334        }
335        for (i, seg) in self.0.iter().enumerate() {
336            match seg {
337                Seg::Key(k) if is_plain_key(k) => {
338                    if i > 0 {
339                        f.write_str(".")?;
340                    }
341                    f.write_str(k)?;
342                }
343                Seg::Key(k) => write!(f, "[{k:?}]")?,
344                Seg::Index(n) => write!(f, "[{n}]")?,
345            }
346        }
347        Ok(())
348    }
349}
350
351fn is_plain_key(k: &str) -> bool {
352    let mut chars = k.chars();
353    chars
354        .next()
355        .is_some_and(|c| c.is_ascii_alphabetic() || c == '_' || c == '$')
356        && chars.all(|c| c.is_ascii_alphanumeric() || c == '_' || c == '$')
357}
yog_data/value.rs

yog_data/
value.rs
