Enum ValidationWarning 

pub enum ValidationWarning {
    DegenerateGeometric {
        strategy: StrategyName,
    },
    LhsDegenerate,
    TriviallyTrueFilter,
    TriviallyFalseFilter,
    EmptySource {
        var: String,
        source: Option<String>,
    },
    SingletonCombinator {
        combinator: &'static str,
    },
    UnresolvedNames {
        reads: Vec<NameRead>,
    },
}

Non-blocking warning for degenerate-but-defined compositions (comprehension_forms.md §5.8).

Variants

DegenerateGeometric

Lattice-geometric strategy (Extrema / Shells / Diagonal / Antidiagonal) over a 1-axis input. Collapses to {first, last} or a trivial walk; usually not what the author meant.

Fields

strategy: StrategyName

The strategy applied.

LhsDegenerate

Lhs over a 1-axis input. Equivalent to Shuffle; two names for one behavior.

TriviallyTrueFilter

filter(c, "true"). Empty-effect filter — usually a bug-shaped predicate. The optimizer’s R0a elides it.

TriviallyFalseFilter

filter(c, "false"). Empty dispense sequence. If intentional, use an empty literal source; otherwise the predicate is bug-shaped.

EmptySource

A clause whose source is provably empty: its cardinality is Bounded(0) (x in [], x in 5..5, a context-free generator the compile evaluated to nothing). The clause is well-formed and an empty stream is a legal value, so this is degenerate rather than wrong — but it empties every cartesian it takes part in, so a whole traversal dispenses nothing and usually that is a typo in the source.

A source whose count is not known at construction (an interpolated call, a parameter without a length) is Unbounded, never Bounded(0), so it cannot reach here: emptiness it discovers at evaluation is reported by the per-clause yields instead (super::runtime::ClauseYield).

Fields

var: String

The clause’s element name.

source: Option<String>

The source’s canonical text, when it has one.

SingletonCombinator

Singleton variant of a combinator: zip([c], _), cartesian(c), union(c). Identity per comprehension_forms.md §4.2 I1-I3; the optimizer’s R0a elides it.

Fields

combinator: &'static str

The combinator with one child.

UnresolvedNames

V3 outside strictness (§5 V3): names the comprehension reads that neither it binds nor the surface supplies. The comprehension compiles, and each such name reads None. A Strict compile refuses it as ValidationError::V3UnresolvedNames.

Fields

reads: Vec<NameRead>

Each such name, with where it is read, in tree order.

Trait Implementations

impl Clone for ValidationWarning

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ValidationWarning

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

Formats the value using the given formatter.

impl Display for ValidationWarning

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

Formats the value using the given formatter.

impl PartialEq for ValidationWarning

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for ValidationWarning