Add simul-lattice crate for discrete space simulations

Cargo.lock

@@ -2923,6 +2923,7 @@ dependencies = [
  "rand 0.9.2",
  "simul-core",
  "simul-euclidean",
+ "simul-lattice",
 ]
 
 [[package]]
@@ -2957,6 +2958,17 @@ dependencies = [
  "thiserror",
 ]
 
+[[package]]
+name = "simul-lattice"
+version = "0.1.0"
+dependencies = [
+ "approx",
+ "nalgebra",
+ "rand 0.9.2",
+ "rand_distr",
+ "simul-core",
+]
+
 [[package]]
 name = "slab"
 version = "0.4.12"

Cargo.toml

@@ -4,7 +4,7 @@ members = [
     "simul-core",
     "simul-euclidean",
     "simul-io",
-    "simul",
+    "simul", "simul-lattice",
 ]
 
 [workspace.package]
@@ -30,4 +30,5 @@ approx = "0.5"
 # Internal crates
 simul-core = { path = "simul-core" }
 simul-euclidean = { path = "simul-euclidean" }
-simul-io = { path = "simul-io" }
+simul-io = { path = "simul-io" }
+simul-lattice = { path = "simul-lattice" }

simul-lattice/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "simul-lattice"
+description = "Lattice space simulations (MD, Brownian, Langevin) for the simul framework"
+version.workspace = true
+edition.workspace = true
+license.workspace = true
+
+[dependencies]
+simul-core = { workspace = true }
+nalgebra = { workspace = true }
+rand = { workspace = true }
+rand_distr = { workspace = true }
+
+[dev-dependencies]
+approx = { workspace = true }
+nalgebra = { workspace = true }

simul-lattice/src/dynamics/mod.rs

@@ -0,0 +1 @@
+

simul-lattice/src/lib.rs

@@ -0,0 +1,10 @@
+//! simul-lattice: Discrete space simulations
+//!
+//! This crate provides implementations for simulations in discrete space:
+//! - Molecular dynamics (Verlet integrator)
+//! - Langevin dynamics (stochastic)
+//! - Brownian dynamics (overdamped)
+
+pub mod dynamics;
+pub mod prelude;
+pub mod space;

simul-lattice/src/prelude.rs

@@ -0,0 +1 @@
+

simul-lattice/src/space.rs

@@ -0,0 +1,60 @@
+//! Lattice space implementation
+
+use nalgebra::SVector;
+use simul_core::space::StateSpace;
+
+/// D-dimensional Lattice space
+///
+/// This is the standard discrete space for molecular dynamics and Brownian motion.
+/// Points are represented as D-dimensional vectors of i32.
+#[derive(Clone, Debug, Default)]
+pub struct Lattice<const D: usize>;
+
+impl<const D: usize> StateSpace for Lattice<D> {
+    const DIM: usize = D;
+
+    type Point = SVector<i32, D>;
+    type Momentum = SVector<i32, D>;
+
+    fn is_continuous() -> bool {
+        false
+    }
+
+    fn name() -> &'static str {
+        match D {
+            1 => "Lattice 1D",
+            2 => "Lattice 2D",
+            3 => "Lattice 3D",
+            _ => "Lattice ND",
+        }
+    }
+
+    fn zero_point() -> Self::Point {
+        SVector::zeros()
+    }
+
+    fn zero_momentum() -> Self::Momentum {
+        SVector::zeros()
+    }
+}
+
+/// Type alias for 1D Lattice space
+pub type Space1D = Lattice<1>;
+
+/// Type alias for 2D Lattice space
+pub type Space2D = Lattice<2>;
+
+/// Type alias for 3D Lattice space
+pub type Space3D = Lattice<3>;
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_lattice_3d() {
+        assert_eq!(Lattice::<3>::DIM, 3);
+        assert!(!Lattice::<3>::is_continuous());
+        assert_eq!(Lattice::<3>::name(), "Lattice 3D");
+    }
+}

simul/Cargo.toml

@@ -8,14 +8,15 @@ license.workspace = true
 [features]
 default = ["euclidean"]
 euclidean = ["simul-euclidean"]
-# lattice = ["simul-lattice"]  # Future
+lattice = ["simul-lattice"]
 
 [dependencies]
 simul-core = { workspace = true }
 simul-euclidean = { workspace = true, optional = true }
+simul-lattice = { workspace = true, optional = true }
 nalgebra = { workspace = true }
 rand = { workspace = true }
-# simul-lattice = { workspace = true, optional = true }  # Future
+
 
 [[example]]
 name = "hello_argon"

simul/src/lib.rs

@@ -27,6 +27,10 @@ pub use simul_core as core;
 #[cfg(feature = "euclidean")]
 pub use simul_euclidean as euclidean;
 
+// Re-export lattice (when feature enabled)
+#[cfg(feature = "lattice")]
+pub use simul_lattice as lattice;
+
 pub mod prelude {
     //! Convenient re-exports for common use
     //!
@@ -43,4 +47,8 @@ pub mod prelude {
     // Euclidean types (when enabled)
     #[cfg(feature = "euclidean")]
     pub use simul_euclidean::prelude::*;
+
+    // Lattice types (when enabled)
+    #[cfg(feature = "lattice")]
+    pub use simul_lattice::prelude::*;
 }