Struct DimExpr 

pub struct DimExpr { /* private fields */ }

A canonical integer polynomial over symbolic dimensions.

Invariant: terms never contains a zero coefficient, and every key ([Monomial]) is sorted ascending. The empty map is the integer 0.

The overflow flag marks an expression whose exact value could not be represented because a coefficient combiner exceeded i64 range. Such an expression is an opaque unknown (see the module-level overflow contract): it is never a constant or bare symbol, and it lowers to a fresh symbol.

Implementations

impl DimExpr

pub fn constant(n: i64) -> DimExpr

The constant n.

pub fn symbol(s: SymbolId) -> DimExpr

A single symbolic dimension.

pub fn overflow() -> DimExpr

An opaque unknown produced by an arithmetic overflow. See the module-level overflow contract. It reports as neither a constant nor a bare symbol, poisons any arithmetic it participates in, and lowers to a fresh symbol.

pub fn is_overflow(&self) -> bool

Whether this expression is the overflow/unknown sentinel.

pub fn as_const(&self) -> Option<i64>

The integer value, if this expression is a pure constant (includes 0).

pub fn as_symbol(&self) -> Option<SymbolId>

The single symbol, if this expression is exactly one symbol with coefficient 1 (e.g. a bare Dim::Symbolic round-trips through this).

pub fn is_const(&self) -> bool

Whether this is a pure constant.

pub fn add(&self, other: &DimExpr) -> DimExpr

self + other.

Overflow-safe: an out-of-range coefficient sum degrades the result to DimExpr::overflow (never panics, never wraps). See the module-level overflow contract.

pub fn sub(&self, other: &DimExpr) -> DimExpr

self - other.

Overflow-safe: see add.

pub fn mul(&self, other: &DimExpr) -> DimExpr

self * other.

Overflow-safe: an out-of-range coefficient product or accumulation degrades the result to DimExpr::overflow. See add.

pub fn checked_div(&self, other: &DimExpr) -> Option<DimExpr>

self / other, only when the division is exact.

Handles the cases the op set actually produces: division by a non-zero constant (every coefficient must divide evenly) and division by a single monomial (symbol cancellation, as in Reshape -1 inference where total = b*s*768 is divided by b*s*12 to yield 64). Anything else — dividing by a multi-term polynomial, or a non-exact quotient — returns None so the caller can degrade to a fresh symbol.

pub fn product(exprs: &[DimExpr]) -> DimExpr

The product of a slice of expressions (1 for an empty slice).

Trait Implementations

impl Clone for DimExpr

fn clone(&self) -> DimExpr

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DimExpr

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

Formats the value using the given formatter.

impl Default for DimExpr

fn default() -> DimExpr

Returns the “default value” for a type.

impl Eq for DimExpr

impl From<Dim> for DimExpr

fn from(d: Dim) -> DimExpr

Converts to this type from the input type.

impl Hash for DimExpr

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for DimExpr

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for DimExpr