Support for schematics file format

Cargo.toml

@@ -20,6 +20,7 @@ default = [
     "network",
     "player_list",
     "world_border",
+    "schem",
     "weather",
 ]
 advancement = ["dep:valence_advancement"]
@@ -30,6 +31,7 @@ log = ["dep:bevy_log"]
 network = ["dep:valence_network"]
 player_list = ["dep:valence_player_list"]
 world_border = ["dep:valence_world_border"]
+schem = ["dep:valence_schem"]
 weather = ["dep:valence_weather"]
 
 [dependencies]
@@ -57,6 +59,7 @@ valence_network = { workspace = true, optional = true }
 valence_player_list = { workspace = true, optional = true }
 valence_registry.workspace = true
 valence_world_border = { workspace = true, optional = true }
+valence_schem = { workspace = true, optional = true }
 valence_packet.workspace = true
 valence_weather = { workspace = true, optional = true }
 
@@ -166,6 +169,7 @@ url = { version = "2.2.2", features = ["serde"] }
 uuid = "1.3.1"
 valence_advancement.path = "crates/valence_advancement"
 valence_anvil.path = "crates/valence_anvil"
+valence_schem.path = "crates/valence_schem"
 valence_biome.path = "crates/valence_biome"
 valence_block.path = "crates/valence_block"
 valence_build_utils.path = "crates/valence_build_utils"

crates/valence_block/Cargo.toml

@@ -5,6 +5,7 @@ edition.workspace = true
 
 [dependencies]
 valence_core.workspace = true
+thiserror.workspace = true
 anyhow.workspace = true
 glam.workspace = true
 

crates/valence_block/src/lib.rs

@@ -22,8 +22,10 @@ use std::fmt;
 use std::fmt::Display;
 use std::io::Write;
 use std::iter::FusedIterator;
+use std::str::FromStr;
 
 use anyhow::Context;
+use thiserror::Error;
 use valence_core::ident;
 use valence_core::ident::Ident;
 use valence_core::item::ItemKind;
@@ -100,6 +102,53 @@ impl Decode<'_> for BlockKind {
     }
 }
 
+#[derive(Debug, Error, PartialEq, Eq)]
+pub enum ParseBlockStateError {
+    #[error("unknown block kind '{0}'")]
+    UnknownBlockKind(String),
+    #[error("invalid prop string '{0}'")]
+    InvalidPropString(String),
+    #[error("unknown prop name '{0}'")]
+    UnknownPropName(String),
+    #[error("unknown prop value '{0}'")]
+    UnknownPropValue(String),
+}
+
+impl FromStr for BlockState {
+    type Err = ParseBlockStateError;
+
+    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
+        let state = match s.split_once('[') {
+            Some((kind, props)) => {
+                let Some(kind) = BlockKind::from_str(kind) else {
+                    return Err(ParseBlockStateError::UnknownBlockKind(kind.to_string()));
+                };
+                props[..props.len() - 1]
+                    .split(',')
+                    .map(|prop| prop.trim())
+                    .try_fold(kind.to_state(), |state, prop| {
+                        let Some((name, val)) = prop.split_once('=') else {
+                            return Err(ParseBlockStateError::InvalidPropString(prop.to_string()));
+                        };
+                        let Some(name) = PropName::from_str(name) else {
+                            return Err(ParseBlockStateError::UnknownPropName(name.to_string()));
+                        };
+                        let Some(val) = PropValue::from_str(val) else {
+                            return Err(ParseBlockStateError::UnknownPropValue(val.to_string()));
+                        };
+                        Ok(state.set(name, val))
+                    })?
+            }
+            None => match BlockKind::from_str(s) {
+                Some(kind) => kind.to_state(),
+                None => return Err(ParseBlockStateError::UnknownBlockKind(s.to_string())),
+            },
+        };
+
+        Ok(state)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

crates/valence_schem/Cargo.toml

@@ -0,0 +1,23 @@
+[package]
+name = "valence_schem"
+description = "A library for the Sponge Schematic Format."
+documentation.workspace = true
+repository = "https://github.com/valence-rs/valence/tree/main/crates/valence_schem"
+readme = "README.md"
+license.workspace = true
+keywords = ["schematics", "minecraft", "deserialization"]
+version.workspace = true
+edition.workspace = true
+
+[dependencies]
+flate2.workspace = true
+glam.workspace = true
+thiserror.workspace = true
+valence_biome.workspace = true
+valence_block.workspace = true
+valence_core.workspace = true
+valence_instance.workspace = true
+valence_nbt.workspace = true
+
+[dev-dependencies]
+valence.workspace = true

crates/valence_schem/README.md

@@ -0,0 +1,43 @@
+# valence_schem
+
+Support for the [Sponge schematic file format](https://github.com/SpongePowered/Schematic-Specification).
+
+This crate implements [Sponge schematics]
+
+Loading schematics (version 1 through 3) from [`Compounds`](Compound) is
+supported. Saving schematics to [`Compounds`](Compound) (version 3 only) is
+supported.
+
+# Examples
+
+An example that shows how to load and save [schematics] from and to the
+filesystem
+
+```rust
+# use valence_schem::Schematic;
+use flate2::Compression;
+fn schem_from_file(path: &str) -> Schematic {
+    Schematic::load(path).unwrap()
+}
+fn schem_to_file(schematic: &Schematic, path: &str) {
+    schematic.save(path);
+}
+```
+
+There are also methods to serialize and deserialize [schematics] from and to
+[`Compounds`](Compound):
+```rust
+# use valence_schem::Schematic;
+use valence_nbt::Compound;
+fn schem_from_compound(compound: &Compound) {
+    let schematic = Schematic::deserialize(compound).unwrap();
+    let comp = schematic.serialize();
+}
+```
+
+### See also
+
+Examples in the `examples/` directory
+
+[Sponge schematics]: <https://github.com/SpongePowered/Schematic-Specification>
+[schematics]: Schematic