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    /// Yog text: `{b|bold} and {#8d6acc|color}`.
28    Text(String),
29    /// An image source: `sprite:button`, `mymod:gui/logo`, `item:minecraft:stick`.
30    Image(String),
31    /// `0xAARRGGBB`.
32    Color(u32),
33}
34
35/// A reference to content: its kind (`item`, `block`, `entity`, `recipe`,
36/// `entry`, `category`, or a mod's own) and id (`minecraft:stick`,
37/// `minecraft:furnace[facing=north]`).
38#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
39pub struct Ref {
40    pub kind: String,
41    pub id: String,
42}
43
44impl Ref {
45    pub fn new(kind: impl Into<String>, id: impl Into<String>) -> Self {
46        Self {
47            kind: kind.into(),
48            id: id.into(),
49        }
50    }
51
52    /// The namespace of the id (`minecraft` for an id without one).
53    pub fn namespace(&self) -> &str {
54        self.id.split_once(':').map_or("minecraft", |(ns, _)| ns)
55    }
56}
57
58/// A mod resource: `@<set>.<key>` — `@Strings.screen.title` is set
59/// `Strings`, key `screen.title`.
60#[derive(Debug, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
61pub struct Res {
62    pub set: String,
63    pub key: String,
64}
65
66/// A map: entries in file order, keys unique.
67#[derive(Debug, Clone, PartialEq, Default)]
68pub struct Map(Vec<(String, Value)>);
69
70impl Map {
71    pub fn new() -> Self {
72        Self(Vec::new())
73    }
74
75    pub fn with_capacity(n: usize) -> Self {
76        Self(Vec::with_capacity(n))
77    }
78
79    pub fn get(&self, key: &str) -> Option<&Value> {
80        self.0.iter().find(|(k, _)| k == key).map(|(_, v)| v)
81    }
82
83    pub fn get_mut(&mut self, key: &str) -> Option<&mut Value> {
84        self.0.iter_mut().find(|(k, _)| k == key).map(|(_, v)| v)
85    }
86
87    /// The position of `key` among the entries.
88    pub fn index_of(&self, key: &str) -> Option<usize> {
89        self.0.iter().position(|(k, _)| k == key)
90    }
91
92    /// Sets `key`, in place if it's there, else at the end; returns the old value.
93    pub fn insert(&mut self, key: impl Into<String>, value: Value) -> Option<Value> {
94        let key = key.into();
95        match self.get_mut(&key) {
96            Some(slot) => Some(std::mem::replace(slot, value)),
97            None => {
98                self.0.push((key, value));
99                None
100            }
101        }
102    }
103
104    /// Appends without checking for the key — for decoders that already did.
105    pub(crate) fn push_unchecked(&mut self, key: String, value: Value) {
106        self.0.push((key, value));
107    }
108
109    pub fn remove(&mut self, key: &str) -> Option<Value> {
110        let i = self.index_of(key)?;
111        Some(self.0.remove(i).1)
112    }
113
114    pub fn len(&self) -> usize {
115        self.0.len()
116    }
117
118    pub fn is_empty(&self) -> bool {
119        self.0.is_empty()
120    }
121
122    pub fn iter(&self) -> impl ExactSizeIterator<Item = (&str, &Value)> {
123        self.0.iter().map(|(k, v)| (k.as_str(), v))
124    }
125
126    pub fn keys(&self) -> impl ExactSizeIterator<Item = &str> {
127        self.0.iter().map(|(k, _)| k.as_str())
128    }
129
130    pub fn retain(&mut self, mut keep: impl FnMut(&str, &Value) -> bool) {
131        self.0.retain(|(k, v)| keep(k, v));
132    }
133}
134
135impl IntoIterator for Map {
136    type Item = (String, Value);
137    type IntoIter = std::vec::IntoIter<(String, Value)>;
138    fn into_iter(self) -> Self::IntoIter {
139        self.0.into_iter()
140    }
141}
142
143impl<K: Into<String>> FromIterator<(K, Value)> for Map {
144    fn from_iter<I: IntoIterator<Item = (K, Value)>>(iter: I) -> Self {
145        let mut map = Map::new();
146        for (k, v) in iter {
147            map.insert(k, v);
148        }
149        map
150    }
151}
152
153impl Value {
154    /// The type's name, for messages: `"a string"`, `"a list"`, ...
155    pub fn kind_name(&self) -> &'static str {
156        match self {
157            Value::Null => "null",
158            Value::Bool(_) => "true/false",
159            Value::Int(_) => "an integer",
160            Value::Float(_) => "a number",
161            Value::Str(_) => "a string",
162            Value::List(_) => "a list",
163            Value::Map(_) => "an object",
164            Value::Ref(_) => "a reference",
165            Value::Tag(_) => "a tag",
166            Value::Res(_) => "a resource",
167            Value::Text(_) => "a text",
168            Value::Image(_) => "an image",
169            Value::Color(_) => "a color",
170        }
171    }
172
173    pub fn is_null(&self) -> bool {
174        matches!(self, Value::Null)
175    }
176
177    pub fn as_bool(&self) -> Option<bool> {
178        match self {
179            Value::Bool(b) => Some(*b),
180            _ => None,
181        }
182    }
183
184    pub fn as_i64(&self) -> Option<i64> {
185        match self {
186            Value::Int(n) => Some(*n),
187            Value::Float(f) if f.fract() == 0.0 && f.abs() < 9.0e15 => Some(*f as i64),
188            _ => None,
189        }
190    }
191
192    pub fn as_f64(&self) -> Option<f64> {
193        match self {
194            Value::Int(n) => Some(*n as f64),
195            Value::Float(f) => Some(*f),
196            _ => None,
197        }
198    }
199
200    /// The string of a `Str` (and of the string-like typed values: `Text`, `Image`).
201    pub fn as_str(&self) -> Option<&str> {
202        match self {
203            Value::Str(s) | Value::Text(s) | Value::Image(s) => Some(s),
204            _ => None,
205        }
206    }
207
208    pub fn as_list(&self) -> Option<&[Value]> {
209        match self {
210            Value::List(l) => Some(l),
211            _ => None,
212        }
213    }
214
215    pub fn as_map(&self) -> Option<&Map> {
216        match self {
217            Value::Map(m) => Some(m),
218            _ => None,
219        }
220    }
221
222    /// `self[key]` of a map, `None` for anything else.
223    pub fn get(&self, key: &str) -> Option<&Value> {
224        self.as_map()?.get(key)
225    }
226
227    /// The value at `path`.
228    pub fn at(&self, path: &Path) -> Option<&Value> {
229        let mut v = self;
230        for seg in path.segments() {
231            v = match (seg, v) {
232                (Seg::Key(k), Value::Map(m)) => m.get(k)?,
233                (Seg::Index(i), Value::List(l)) => l.get(*i)?,
234                _ => return None,
235            };
236        }
237        Some(v)
238    }
239}
240
241impl From<bool> for Value {
242    fn from(b: bool) -> Self {
243        Value::Bool(b)
244    }
245}
246impl From<i64> for Value {
247    fn from(n: i64) -> Self {
248        Value::Int(n)
249    }
250}
251impl From<f64> for Value {
252    fn from(f: f64) -> Self {
253        Value::Float(f)
254    }
255}
256impl From<&str> for Value {
257    fn from(s: &str) -> Self {
258        Value::Str(s.to_string())
259    }
260}
261impl From<String> for Value {
262    fn from(s: String) -> Self {
263        Value::Str(s)
264    }
265}
266impl From<Vec<Value>> for Value {
267    fn from(l: Vec<Value>) -> Self {
268        Value::List(l)
269    }
270}
271impl From<Map> for Value {
272    fn from(m: Map) -> Self {
273        Value::Map(m)
274    }
275}
276
277/// One step of a [`Path`].
278#[derive(Debug, Clone, PartialEq, Eq, Hash)]
279pub enum Seg {
280    Key(String),
281    Index(usize),
282}
283
284/// Where a value is in a document: `entries[2].pages[0].item`.
285#[derive(Debug, Clone, PartialEq, Eq, Hash, Default)]
286pub struct Path(Vec<Seg>);
287
288impl Path {
289    pub fn root() -> Self {
290        Self(Vec::new())
291    }
292
293    pub fn segments(&self) -> &[Seg] {
294        &self.0
295    }
296
297    pub fn is_root(&self) -> bool {
298        self.0.is_empty()
299    }
300
301    pub fn push(&mut self, seg: Seg) {
302        self.0.push(seg);
303    }
304
305    pub fn pop(&mut self) {
306        self.0.pop();
307    }
308
309    pub fn key(&self, key: &str) -> Path {
310        let mut p = self.clone();
311        p.0.push(Seg::Key(key.to_string()));
312        p
313    }
314
315    pub fn index(&self, i: usize) -> Path {
316        let mut p = self.clone();
317        p.0.push(Seg::Index(i));
318        p
319    }
320}
321
322impl fmt::Display for Path {
323    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
324        if self.0.is_empty() {
325            return f.write_str("(root)");
326        }
327        for (i, seg) in self.0.iter().enumerate() {
328            match seg {
329                Seg::Key(k) if is_plain_key(k) => {
330                    if i > 0 {
331                        f.write_str(".")?;
332                    }
333                    f.write_str(k)?;
334                }
335                Seg::Key(k) => write!(f, "[{k:?}]")?,
336                Seg::Index(n) => write!(f, "[{n}]")?,
337            }
338        }
339        Ok(())
340    }
341}
342
343fn is_plain_key(k: &str) -> bool {
344    let mut chars = k.chars();
345    chars
346        .next()
347        .is_some_and(|c| c.is_ascii_alphabetic() || c == '_' || c == '$')
348        && chars.all(|c| c.is_ascii_alphanumeric() || c == '_' || c == '$')
349}
yog_data/value.rs

yog_data/
value.rs
