Added block matching macro

Author: ReCore-sys

Cargo.toml

@@ -146,7 +146,6 @@ ahash = "0.8.12"
 serde = { version = "1.0.228", features = ["derive"] }
 serde_json = "1.0.145"
 serde_derive = "1.0.228"
-serde_yaml_ng = "0.10.0"
 base64 = "0.22.1"
 
 # When if bitcode's latest version has been changed, see if clippy still complains about
@@ -171,7 +170,6 @@ lazy_static = "1.5.0"
 quote = "1.0.41"
 syn = "2.0.106"
 proc-macro2 = "1.0.101"
-proc-macro-crate = "3.4.0"
 paste = "1.0.15"
 maplit = "1.0.2"
 macro_rules_attribute = "0.2.2"

src/lib/derive_macros/src/block/matches.rs

@@ -0,0 +1,62 @@
+use crate::block::JSON_FILE;
+use proc_macro::TokenStream;
+use quote::quote;
+use simd_json::base::{ValueAsObject, ValueAsScalar};
+use simd_json::derived::ValueObjectAccess;
+
+struct Input {
+    name: String,
+    id_var: syn::Expr,
+}
+
+impl syn::parse::Parse for Input {
+    fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
+        let name_lit: syn::LitStr = input.parse()?;
+        let _comma: syn::Token![,] = input.parse()?;
+        let id_var: syn::Expr = input.parse()?;
+        Ok(Input {
+            name: name_lit.value(),
+            id_var,
+        })
+    }
+}
+
+// match_block!("stone", block_id); -> "if block_id == BlockId(1) { ... }
+// match_block!("dirt", block_id); -> "if block_name == BlockId( { ... }
+pub fn matches_block(input: TokenStream) -> TokenStream {
+    let input = syn::parse_macro_input!(input as Input);
+    let block_name = &input.name;
+    let block_name = if block_name.starts_with("minecraft:") {
+        block_name.to_string()
+    } else {
+        format!("minecraft:{}", block_name)
+    };
+    let block_id_var = &input.id_var;
+    let mut buf = JSON_FILE.to_vec();
+    let v = simd_json::to_owned_value(&mut buf).unwrap();
+    let filtered_names = v
+        .as_object()
+        .unwrap()
+        .iter()
+        .filter(|(_, v)| v.get("name").as_str() == Some(&block_name))
+        .map(|(k, v)| (k.parse::<u32>().unwrap(), v))
+        .collect::<Vec<_>>();
+    if filtered_names.is_empty() {
+        return syn::Error::new_spanned(
+            &input.id_var,
+            format!("Block name '{}' not found in registry", block_name),
+        )
+        .to_compile_error()
+        .into();
+    }
+    let mut arms = Vec::new();
+    for (id, _) in filtered_names {
+        arms.push(quote! {
+            #block_id_var == BlockId(#id)
+        });
+    }
+    let joined = quote! {
+        #(#arms)||*
+    };
+    joined.into()
+}

src/lib/derive_macros/src/block/mod.rs

@@ -6,6 +6,8 @@ use syn::parse::{Parse, ParseStream};
 use syn::punctuated::Punctuated;
 use syn::{braced, Expr, Ident, Lit, LitStr, Result, Token};
 
+pub(crate) mod matches;
+
 const JSON_FILE: &[u8] = include_bytes!("../../../../../assets/data/blockstates.json");
 
 struct Input {

src/lib/derive_macros/src/lib.rs

@@ -1,5 +1,6 @@
 #![feature(proc_macro_quote)]
 
+use block::matches;
 use proc_macro::TokenStream;
 
 mod block;
@@ -122,3 +123,22 @@ pub fn build_registry_packets(input: TokenStream) -> TokenStream {
 pub fn block(input: TokenStream) -> TokenStream {
     block::block(input)
 }
+
+/// A macro to check if a block ID matches a given block name at compile time.
+/// Usage:
+/// ```
+/// # use ferrumc_macros::{match_block};
+/// # use ferrumc_world::block_id::BlockId;
+/// let block_id = BlockId(1);
+/// if match_block!("stone", block_id) {
+///     // do something
+/// }
+/// ```
+/// Unfortunately, due to current limitations in Rust's proc macros, you will need to import the
+/// `BlockId` struct manually.
+///
+/// The `minecraft:` namespace is optional and will be added automatically if not present.
+#[proc_macro]
+pub fn match_block(input: TokenStream) -> TokenStream {
+    matches::matches_block(input)
+}