Struct NlProblemParts 

pub struct NlProblemParts {
    pub minimize: bool,
    pub objective: Expr,
    pub obj_constant: f64,
    pub constraints: Vec<Expr>,
    pub x_l: Vec<f64>,
    pub x_u: Vec<f64>,
    pub x0: Vec<f64>,
    pub g_l: Vec<f64>,
    pub g_u: Vec<f64>,
    pub var_names: Vec<String>,
    pub con_names: Vec<String>,
}

The pieces of a model built in memory, as handed to NlProblem::from_expressions.

Everything is expressed as Expr trees — there is no linear/nonlinear split to fill in, because the AD tape treats a linear term exactly like any other subexpression (.nl’s J/G segments are a file-format optimization, not an evaluator requirement). n is taken from the length of x_l; m from the length of constraints.

One cost to that simplification, in metadata rather than values: with con_linear empty, get_constraints_linearity tags a row Linear only when its expression is literally Const(0.0), so a genuinely linear row built here reports NonLinear. Presolve consumes that tag, and the direction is the safe one — it loses tightening it could have done, and never asserts linearity that does not hold — but a frontend that cares about presolve strength on linear rows should know the tag is pessimistic on this path.

Fields

minimize: bool

true to minimize objective, false to maximize it. Matches NlProblem::minimize: the evaluator negates a maximize objective so callers always see the minimization form.

objective: Expr

Objective expression.

obj_constant: f64

Constant offset added to the objective.

constraints: Vec<Expr>

One expression per constraint row; row i is bounded by g_l[i] <= constraints[i](x) <= g_u[i].

x_l: Vec<f64>

Variable bounds and starting point, each length n. Use ±1e19 for “unbounded”, the same sentinel the .nl reader emits.

x_u: Vec<f64>

x0: Vec<f64>

g_l: Vec<f64>

Constraint bounds, each length m. g_l[i] == g_u[i] is an equality row.

g_u: Vec<f64>

var_names: Vec<String>

Optional names, index-aligned to x / g. Empty is fine — every consumer falls back to indices (see NlProblem::var_names).

con_names: Vec<String>

Trait Implementations

impl Clone for NlProblemParts

fn clone(&self) -> NlProblemParts

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for NlProblemParts

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

Formats the value using the given formatter.