Re-visit From impl for native data types found in NBT data format. (#169)

Cargo.toml

@@ -36,7 +36,7 @@ thiserror = "1.0.35"
 tracing = "0.1.37"
 url = { version = "2.2.2", features = ["serde"] }
 uuid = { version = "1.1.2", features = ["serde"] }
-valence_nbt = { version = "0.4.0", path = "valence_nbt" }
+valence_nbt = { version = "0.5.0", path = "valence_nbt" }
 valence_protocol = { version = "0.1.0", path = "valence_protocol", features = ["encryption", "compression"] }
 vek = "0.15.8"
 

valence_nbt/Cargo.toml

@@ -6,7 +6,7 @@ repository = "https://github.com/valence-rs/valence/tree/main/valence_nbt"
 readme = "README.md"
 license = "MIT"
 keywords = ["nbt", "minecraft", "serialization"]
-version = "0.4.0"
+version = "0.5.0"
 authors = ["Ryan Johnson <ryanj00a@gmail.com>"]
 edition = "2021"
 

valence_nbt/src/value.rs

@@ -72,6 +72,56 @@ impl List {
     }
 }
 
+/// We can not create new identities in stable Rust using macros, so we provide
+/// them in the macro invocation itself.
+macro_rules! nbt_conversion {
+    ( $($nbt_type:ident = $value_type:ty => $is_function:ident $as_function:ident $as_mut_function:ident $into_function:ident)+ ) => {
+        $(
+            pub fn $is_function(&self) -> bool {
+                self.$as_function().is_some()
+            }
+
+            pub fn $as_function(&self) -> Option<&$value_type> {
+                match self {
+                    Self::$nbt_type(value) => Some(value),
+                    _ => None
+                }
+            }
+
+            pub fn $as_mut_function(&mut self) -> Option<&mut $value_type> {
+                match self {
+                    Self::$nbt_type(value) => Some(value),
+                    _ => None
+                }
+            }
+
+            pub fn $into_function(self) -> Option<$value_type> {
+                match self {
+                    Self::$nbt_type(value) => Some(value),
+                    _ => None
+                }
+            }
+        )*
+    };
+}
+
+impl Value {
+    nbt_conversion! {
+        Byte = i8 => is_byte as_byte as_byte_mut into_byte
+        Short = i16 => is_short as_short as_short_mut into_short
+        Int = i32 => is_int as_int as_int_mut into_int
+        Long = i64 => is_long as_long as_long_mut into_long
+        Float = f32 => is_float as_float as_float_mut into_float
+        Double = f64 => is_double as_double as_double_mut into_double
+        ByteArray = Vec<i8> => is_byte_array as_byte_array as_byte_array_mut into_byte_array
+        String = String => is_string as_string as_string_mut into_string
+        List = List => is_list as_list as_list_mut into_list
+        Compound = Compound => is_compound as_compound as_compound_mut into_compound
+        IntArray = Vec<i32> => is_int_array as_int_array as_int_array_mut into_int_array
+        LongArray = Vec<i64> => is_long_array as_long_array as_long_array_mut into_long_array
+    }
+}
+
 impl From<i8> for Value {
     fn from(v: i8) -> Self {
         Self::Byte(v)
@@ -234,123 +284,3 @@ impl From<Vec<Vec<i64>>> for List {
         List::LongArray(v)
     }
 }
-
-impl From<Value> for Option<i8> {
-    fn from(value: Value) -> Self {
-        if let Value::Byte(b) = value {
-            Some(b)
-        } else {
-            None
-        }
-    }
-}
-
-impl From<Value> for Option<i16> {
-    fn from(value: Value) -> Self {
-        if let Value::Short(val) = value {
-            Some(val)
-        } else {
-            None
-        }
-    }
-}
-
-impl From<Value> for Option<i32> {
-    fn from(value: Value) -> Self {
-        if let Value::Int(val) = value {
-            Some(val)
-        } else {
-            None
-        }
-    }
-}
-
-impl From<Value> for Option<i64> {
-    fn from(value: Value) -> Self {
-        if let Value::Long(val) = value {
-            Some(val)
-        } else {
-            None
-        }
-    }
-}
-
-impl From<Value> for Option<f32> {
-    fn from(value: Value) -> Self {
-        if let Value::Float(val) = value {
-            Some(val)
-        } else {
-            None
-        }
-    }
-}
-
-impl From<Value> for Option<f64> {
-    fn from(value: Value) -> Self {
-        if let Value::Double(val) = value {
-            Some(val)
-        } else {
-            None
-        }
-    }
-}
-
-impl From<Value> for Option<Vec<i8>> {
-    fn from(value: Value) -> Self {
-        if let Value::ByteArray(val) = value {
-            Some(val)
-        } else {
-            None
-        }
-    }
-}
-
-impl From<Value> for Option<String> {
-    fn from(value: Value) -> Self {
-        if let Value::String(val) = value {
-            Some(val)
-        } else {
-            None
-        }
-    }
-}
-
-impl From<Value> for Option<List> {
-    fn from(value: Value) -> Self {
-        if let Value::List(val) = value {
-            Some(val)
-        } else {
-            None
-        }
-    }
-}
-
-impl From<Value> for Option<Compound> {
-    fn from(value: Value) -> Self {
-        if let Value::Compound(val) = value {
-            Some(val)
-        } else {
-            None
-        }
-    }
-}
-
-impl From<Value> for Option<Vec<i32>> {
-    fn from(value: Value) -> Self {
-        if let Value::IntArray(val) = value {
-            Some(val)
-        } else {
-            None
-        }
-    }
-}
-
-impl From<Value> for Option<Vec<i64>> {
-    fn from(value: Value) -> Self {
-        if let Value::LongArray(val) = value {
-            Some(val)
-        } else {
-            None
-        }
-    }
-}

valence_protocol/Cargo.toml

@@ -18,7 +18,7 @@ serde_json = "1.0.87"
 thiserror = "1.0.37"
 uuid = "1.2.1"
 valence_derive = { version = "0.1.0", path = "../valence_derive" }
-valence_nbt = { version = "0.4.0", path = "../valence_nbt" }
+valence_nbt = { version = "0.5.0", path = "../valence_nbt" }
 
 [dev-dependencies]
 rand = "0.8.5"