Struct Model 

pub struct Model {
    pub name: String,
    /* private fields */
}

The optimization model. Owns the expression arena, variable/parameter registries, constraints, and (optional) objective.

Model uses interior mutability so the builder API can take &self references.

Variables, constraints, and the objective are added through RefCells under the hood.

Fields

name: String

Implementations

impl Model

pub fn new(name: impl Into<String>) -> Self

pub fn var(&self, name: impl Into<SmolStr>) -> VarBuilder<'_>

pub fn indexed_var<'a>( &'a self, name: impl Into<String>, set: &Set, ) -> IndexedVarBuilder<'a>

pub fn variable_id(&self, name: &str) -> Option<VarId>

pub fn variables(&self) -> Ref<'_, Vec<Variable>>

pub fn arena(&self) -> Ref<'_, ExprArena>

pub fn num_variables(&self) -> usize

pub fn fix(&self, e: Expr<'_>, value: f64)

Fix a single-variable expression to value. Convenience over Self::fix_var for handles from Model::var or crate::IndexedVar indexing.

Panics

Panics if e is not a bare variable handle.

pub fn fix_var(&self, id: VarId, value: f64)

Fix variable id to value by setting lb = ub = value.

pub fn unfix_var(&self, id: VarId, lb: f64, ub: f64)

Restore bounds on variable id. Pass f64::NEG_INFINITY / f64::INFINITY to restore an unbounded direction.

pub fn param<'a>(&'a self, name: impl Into<SmolStr>, value: f64) -> Expr<'a>

Register a named scalar parameter initialized to value, returning an Expr handle that references it symbolically.

A parameter behaves like a constant coefficient (param * var is linear), but stays symbolic in the expression tree so it can be re-bound with Self::set_param / Self::set_param_id between solves without rebuilding the model.

Panics

Panics if a parameter with the same name is already registered.

pub fn set_param(&self, p: Expr<'_>, value: f64)

Re-bind the parameter referenced by handle p to value.

Panics

Panics if p is not a bare parameter handle (see Self::param).

pub fn set_param_id(&self, id: ParamId, value: f64)

Re-bind parameter id to value. Takes effect on the next solve.

The value is stored only in the expression arena (its single source of truth); extraction and evaluation read it from there.

pub fn param_value(&self, id: ParamId) -> f64

Current value bound to parameter id.

Panics

Panics if id was not produced by Self::param on this model.

pub fn param_value_of(&self, p: Expr<'_>) -> Option<f64>

Current value of the parameter referenced by handle p, or None if p is not a bare parameter handle.

pub fn parameter_id(&self, name: &str) -> Option<ParamId>

pub fn parameters(&self) -> Ref<'_, Vec<Parameter>>

pub fn num_parameters(&self) -> usize

pub fn constraint( &self, name: impl Into<SmolStr>, c: ConstraintExpr<'_>, ) -> ConstraintId

Register a new constraint.

Panics

Panics if a constraint with the same name is already registered, or if the constraint count exceeds u32::MAX.

pub fn add_constraints<'a, I>(&'a self, items: I)

where I: IntoIterator<Item = (SmolStr, ConstraintExpr<'a>)>,

Bulk-register constraints. Each entry is (name, ConstraintExpr). Useful with .par_iter().map(...).collect() style construction.

pub fn add_constraints_over<'a, K, F>( &'a self, name_prefix: &str, set: &Set, rule: F, )

where K: FromIndexKey, F: FnMut(K) -> ConstraintExpr<'a>,

Rule-style bulk constraint registration.

The closure receives the index as a typed value K. Any type implementing FromIndexKey is accepted. Built-in impls cover i64, i32, usize, String, raw IndexKey, and tuples up to arity 4. The user states the expected shape via the closure-arg annotation.

Example

// Scalar set: closure receives a usize directly.
m.add_constraints_over("upper", &i, |i: usize| x[i].le(b[i]));

// Tuple set: destructure inline.
m.add_constraints_over("blo", &(&tasks * &events), |(t, n): (usize, usize)| {
    (b[(t, n)] - b_min[t] * w[(t, n)]).ge(0.0)
});

pub fn constraints(&self) -> Ref<'_, Vec<Constraint>>

pub fn num_constraints(&self) -> usize

pub fn constraint_id(&self, name: &str) -> Option<ConstraintId>

pub fn minimize(&self, expr: Expr<'_>)

pub fn maximize(&self, expr: Expr<'_>)

pub fn objective(&self) -> Ref<'_, Option<Objective>>

pub fn try_objective(&self) -> Result<Objective>

Try to get a cloned copy of the objective.

Errors

Returns Error::NoObjective if no objective is set on this model.

pub fn kind(&self) -> ModelKind

Infer the ModelKind from current variables and expressions. Result is cached and invalidated whenever variables, constraints, or the objective change.

Trait Implementations

impl Debug for Model

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

Formats the value using the given formatter.