Enum AssignmentError 

pub enum AssignmentError {
    DimensionsNotSet,
    CostNotSet,
    GroupLengthMismatch,
    InvalidPin {
        row: usize,
        col: i32,
    },
    Infeasible,
    BudgetExceeded,
}

Errors from AssignmentBuilder::solve.

Variants

DimensionsNotSet

.rows() or .cols() was not called before .solve() (or either was set to zero).

CostNotSet

.cost() was not called before .solve().

GroupLengthMismatch

A custom row_group / col_group slice did not match the declared dimensions.

InvalidPin

A pin references an out-of-range row or a column that is neither SENTINEL nor a valid 0..n_cols index, or whose row-group does not match its target column’s group.

Fields

row: usize

Row index supplied to AssignmentBuilder::pin.

col: i32

Column index (or SENTINEL) supplied to AssignmentBuilder::pin.

Infeasible

The CSP has no feasible solution under the supplied constraints. Note that with SENTINEL always available a pure assignment problem is always feasible; this variant surfaces when pins or group constraints are mutually incompatible.

BudgetExceeded

The branch-and-bound search hit its AssignmentBuilder::node_budget before scoring a single complete assignment, so there is no best-so-far solution to return. Distinct from Infeasible: the problem may well be satisfiable — the search simply ran out of budget. Retry with a larger (or None) node_budget. When the budget is hit after at least one complete assignment was scored, .solve() instead returns Ok with SolveStats::budget_exceeded set on the best-so-far solution.

Trait Implementations

impl Debug for AssignmentError

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

Formats the value using the given formatter.

impl Display for AssignmentError

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

Formats the value using the given formatter.

impl Error for AssignmentError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<AssignmentError> for CspError

AssignmentBuilder’s error family converts too, so py//wasm call sites that touch the assignment/COP path get the same typed exceptions as the Sudoku path for free. Note this conversion is itself evidence of Pass-1 finding R8: Infeasible collapses onto Unsatisfiable here because AssignmentError has no distinct budget-exhaustion variant yet — fixing that is a separate, already ledgered item, not silently patched over by this mapping.

fn from(e: AssignmentError) -> Self

Converts to this type from the input type.