Module supply 

Supply infrastructure for variable relationship tracking.

Supplies provide efficient access to derived information about planning variables, such as inverse relationships (who points to whom) and anchor tracking (chain roots).

Zero-Erasure Design

• Index-based: All supplies store indices, not cloned domain objects
• Owned: Supplies are owned directly, no Arc, Box, or dyn
• Mutation via &mut: Standard Rust ownership, no RwLock or interior mutability
• Generic: Full type information preserved through the entire pipeline

Available Supplies

• InverseSupply: Maps values to entity indices for O(1) inverse lookups
• AnchorSupply: Maps entity indices to anchor indices for chain tracking
• ListStateSupply: Tracks element positions in list variables

Usage

Supplies are owned by the score director or solver scope. They’re created when needed and accessed via regular Rust references:

use solverforge_core::domain::supply::{InverseSupply, AnchorSupply, ListStateSupply};

// Create supplies owned by your containing struct
let mut inverse: InverseSupply<i64> = InverseSupply::new();
let mut anchor = AnchorSupply::new();
let mut list_state: ListStateSupply<usize> = ListStateSupply::new();

// Use with standard Rust ownership
inverse.insert(42, 0);  // value 42 -> entity index 0
anchor.set(0, 5);       // entity 0 -> anchor 5
list_state.assign(10, 0, 0);  // element 10 -> entity 0, position 0

// Read with shared reference
assert_eq!(inverse.get(&42), Some(0));
assert_eq!(anchor.get(0), Some(5));
assert_eq!(list_state.get_entity(&10), Some(0));

Structs

AnchorSupply

Index-based anchor variable supply.

ElementPosition

Position of an element within a list variable.

InverseSupply

Index-based inverse variable supply.

ListStateSupply

Index-based list variable state supply.