Break up library into macros and map nested libraries for shared dependency with constant map macro.

.gitignore

@@ -1,2 +1,2 @@
-/target
+target
 .idea

Cargo.toml

@@ -7,3 +7,7 @@ edition = "2024"
 bighash = []
 assertions = []
 messages = []
+
+[dependencies]
+macros = { path = "macros" }
+map = { path = "map" }

macros/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "macros"
+version = "0.0.0"
+authors = ["paladin <christian.lincoln25@ic.ac.uk>"]
+description = "Procedural macros for Deimos"
+keywords = ["template", "proc_macro", "procmacro"]
+edition = "2018"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+quote = "1"
+proc-macro2 = "1.0"
+syn = "1.0"
+map = { path = "../map" }

macros/src/lib.rs

@@ -0,0 +1,19 @@
+extern crate proc_macro;
+use proc_macro::TokenStream;
+
+use syn::{parse_macro_input, DeriveInput};
+use quote::quote;
+
+/// Example of [function-like procedural macro][1].
+///
+/// [1]: https://doc.rust-lang.org/reference/procedural-macros.html#function-like-procedural-macros
+#[proc_macro]
+pub fn map(input: TokenStream) -> TokenStream {
+    let input = parse_macro_input!(input as DeriveInput);
+
+    let tokens = quote! {
+        const 
+    };
+
+    tokens.into()
+}

map/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "map"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

map/src/lib.rs

@@ -18,7 +18,6 @@ Notes:
 - Values would only need to be shuffled around closer to their 'home' during a resize.
 - It is unlikely the displacement would large value without a resize amending that problem.
  */
-use crate::gc::{AnyId, Id};
 use std::fmt::Debug;
 use std::hash::{DefaultHasher, Hash, Hasher};
 
@@ -51,22 +50,6 @@ impl Hashes for &str {
     }
 }
 
-impl<T> Hashes for Id<T> {
-    fn hashed(&self) -> Hashed {
-        let mut hasher = DefaultHasher::new();
-        self.index.hash(&mut hasher);
-        hasher.finish() as Hashed
-    }
-}
-
-impl Hashes for AnyId {
-    fn hashed(&self) -> Hashed {
-        let mut hasher = DefaultHasher::new();
-        self.index.hash(&mut hasher);
-        hasher.finish() as Hashed
-    }
-}
-
 pub trait TableEntry: Equivalent<Self> + Hashes {
     const VACANT: Self;
     fn is_vacant(&self) -> bool;
@@ -95,6 +78,25 @@ pub struct DisplacementSet<E: TableEntry> {
     map_count: usize, // number of elements in table
 }
 
+pub fn get<E: TableEntry + Equivalent<K> ,K: Hashes>(map: &[Entry<E>], index: K) -> Option<&E> {
+    if map.len() == 0 {
+        return None;
+    }
+    let location = index.hashed() as usize % map.len();
+    let home = &map[location];
+    if home.entry.matches(&index) {
+        Some(&home.entry)
+    } else {
+        for i in 1..home.displacement as usize {
+            let neighbour = &map[(location + i) % map.len()];
+            if neighbour.entry.matches(&index) {
+                return Some(&neighbour.entry);
+            }
+        }
+        None
+    }
+}
+
 impl<E: TableEntry> DisplacementSet<E> {
     fn exchange(&mut self, len: usize) {
         let old = std::mem::replace(
@@ -202,8 +204,8 @@ impl<E: TableEntry> DisplacementSet<E> {
     }
     pub fn remove<K>(&mut self, index: K)
     where
-        E: Equivalent<K>,
+      E: Equivalent<K>,
-        K: Hashes,
+      K: Hashes,
     {
         if self.map.len() == 0 {
             return;
@@ -265,22 +267,7 @@ impl<E: TableEntry> DisplacementSet<E> {
       E: Equivalent<K>,
       K: Hashes,
     {
-        if self.map.len() == 0 {
+        get(self.map.as_slice(),index)
-            return None;
-        }
-        let location = index.hashed() as usize % self.map.len();
-        let home = &self.map[location];
-        if home.entry.matches(&index) {
-            Some(&home.entry)
-        } else {
-            for i in 1..home.displacement as usize {
-                let neighbour = &self.map[(location + i) % self.map.len()];
-                if neighbour.entry.matches(&index) {
-                    return Some(&neighbour.entry);
-                }
-            }
-            None
-        }
     }
     pub fn new() -> DisplacementSet<E> {
         DisplacementSet {

src/gc.rs

@@ -1,6 +1,7 @@
-use std::hash::{Hash, Hasher};
+use std::hash::{DefaultHasher, Hash, Hasher};
 use std::marker::{PhantomData};
 use std::ops::{Deref, DerefMut};
+use map::{Hashed, Hashes};
 
 type Index = u32;
 
@@ -288,3 +289,19 @@ pub trait Traverse<C>: Sized {
   fn traverse(id: &Id<Self>, context: &mut C);
   fn collect(self);
 }
+
+impl<T> Hashes for Id<T> {
+  fn hashed(&self) -> Hashed {
+    let mut hasher = DefaultHasher::new();
+    self.index.hash(&mut hasher);
+    hasher.finish() as Hashed
+  }
+}
+
+impl Hashes for AnyId {
+  fn hashed(&self) -> Hashed {
+    let mut hasher = DefaultHasher::new();
+    self.index.hash(&mut hasher);
+    hasher.finish() as Hashed
+  }
+}

src/lib.rs

@@ -1,5 +1,5 @@
 pub mod gc;
-pub mod map;
+pub use macros;
 #[cfg(test)]
 mod tests {
   #[test]