Struct Method 

pub struct Method { /* private fields */ }

A single method within a relationship.

Its callback must be a pure, deterministic function of its input values and immutable captured constants, with no externally observable side effects. Equal inputs produce equivalent outputs or errors. There is no guarantee that the callback executes, or when or how often it executes. A self-referencing method must also be idempotent. Holding its other inputs fixed, substituting its outputs for overlapping inputs and applying it again produces equivalent outputs.

Every method in a relationship must conform the same constraint and preserve an assignment that already satisfies it. The runtime checks shared cell sets, not this semantic consistency.

Examples

See the relationship example.

Implementations

impl Method

pub fn new<F>( inputs: Vec<CellId>, outputs: Vec<CellId>, input_types: Vec<TypeId>, output_types: Vec<TypeId>, f: F, ) -> Self

where F: Fn(&[&dyn Any]) -> Result<Vec<Box<dyn Any>>, Error> + 'static,

Creates a method from explicit TypeIds and a type-erased function.

• Precondition: inputs.len() == input_types.len() and outputs.len() == output_types.len().
• Precondition: f satisfies Method’s purity and idempotence contract.

Propagation validates the callback’s output count and concrete types before publishing staged values. Declared output order determines positional binding.

• Complexity: O(1) storage work, excluding ownership transfer of declared edges.

Examples

See the relationship example.

pub fn from_fn_1_1<A, B, F>(input: CellId, output: CellId, f: F) -> Self

where A: Any + 'static, B: Any + 'static, F: Fn(&A) -> Result<B, Error> + 'static,

Creates a 1-input, 1-output method from a typed closure.

TypeIds for A and B are captured automatically. The method is validated against its cell registrations when passed to crate::sheet::Sheet::add_relationship.

• Precondition: f satisfies Method’s purity and idempotence contract.

Examples

See the relationship example.

pub fn from_fn_2_1<A, B, C, F>( inputs: [CellId; 2], output: CellId, f: F, ) -> Self

where A: Any + 'static, B: Any + 'static, C: Any + 'static, F: Fn(&A, &B) -> Result<C, Error> + 'static,

Creates a 2-input, 1-output method from a typed closure.

inputs[0] maps to A and inputs[1] maps to B. TypeIds are captured automatically. The method is validated when passed to crate::sheet::Sheet::add_relationship.

• Precondition: f satisfies Method’s purity and idempotence contract.

Examples

See the relationship example.