Struct Reduction

#[non_exhaustive]
pub struct Reduction {
    pub new_expression: Expression,
    pub new_top: Expression,
    pub symbols: HashMap<Name, DecisionVariable>,
}

Represents the result of applying a rule to an expression within a model.

A Reduction encapsulates the changes made to a model during a rule application. It includes a new expression to replace the original one, an optional top-level constraint to be added to the model, and any updates to the model’s symbol table.

This struct allows for representing side-effects of rule applications, ensuring that all modifications, including symbol table expansions and additional constraints, are accounted for and can be applied to the model consistently.

Fields

• new_expression: The updated Expression that replaces the original one after applying the rule.
• new_top: An additional top-level Expression constraint that should be added to the model. If no top-level constraint is needed, this field can be set to Expression::Nothing.
• symbols: A SymbolTable containing any new symbol definitions or modifications to be added to the model’s symbol table. If no symbols are modified, this field can be set to an empty symbol table.

Usage

A Reduction can be created using one of the provided constructors:

• Reduction::new: Creates a reduction with a new expression, top-level constraint, and symbol modifications.
• Reduction::pure: Creates a reduction with only a new expression and no side-effects on the symbol table or constraints.
• Reduction::with_symbols: Creates a reduction with a new expression and symbol table modifications, but no top-level constraint.
• Reduction::with_top: Creates a reduction with a new expression and a top-level constraint, but no symbol table modifications.

The apply method allows for applying the changes represented by the Reduction to a Model.

Example

// Need to add an example

See Also

• ApplicationResult: Represents the result of applying a rule, which may either be a Reduction or an ApplicationError.
• Model: The structure to which the Reduction changes are applied.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

new_expression: Expression

new_top: Expression

symbols: HashMap<Name, DecisionVariable>

Implementations

impl Reduction

pub fn new( new_expression: Expression, new_top: Expression, symbols: HashMap<Name, DecisionVariable>, ) -> Reduction

pub fn pure(new_expression: Expression) -> Reduction

Represents a reduction with no side effects on the model.

pub fn with_symbols( new_expression: Expression, symbols: HashMap<Name, DecisionVariable>, ) -> Reduction

Represents a reduction that also modifies the symbol table.

pub fn with_top(new_expression: Expression, new_top: Expression) -> Reduction

Represents a reduction that also adds a top-level constraint to the model.

pub fn apply(self, model: &mut Model)

Trait Implementations

impl Clone for Reduction

fn clone(&self) -> Reduction

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Reduction

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.