Struct GridExtent 

pub struct GridExtent { /* private fields */ }

A validated grid shape: a non-negative width and height whose product is a cell count the runtime can actually allocate.

This is the only route from a user-supplied Int pair to a cell count. Reaching vec![unit; (w as usize) * (h as usize)] directly would let w = -1 become usize::MAX and the product overflow — either an allocation the host cannot serve (an OOM abort) or a capacity-overflow panic, both crossing extern "C". Neither is expressible here: GridExtent holds usizes, and the multiplication it proves is the one cells() returns.

Implementations

impl GridExtent

pub const MAX_CELLS: usize

The largest grid the runtime will construct: 2^28 cells, which is 2 GiB of GcRef storage before a single cell object exists.

A cap, not a checked_mul, because a product that merely fits in a usize is still an allocation no host can serve — Grid[Int](2^40, 2) multiplies cleanly and then aborts the process. The number is a judgement about what a Praxis program plausibly asks for; a program that wants more gets a fault it can see rather than a SIGKILL it cannot.

pub const fn new(width: i64, height: i64) -> Option<GridExtent>

The extent width × height names, or None if either side is negative or the grid would exceed MAX_CELLS.

pub const fn width(self) -> usize

The column count.

pub const fn height(self) -> usize

The row count.

pub const fn cells(self) -> usize

The total cell count — width * height, proven not to overflow.

Trait Implementations

impl Clone for GridExtent

fn clone(&self) -> GridExtent

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for GridExtent

impl Debug for GridExtent

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

Formats the value using the given formatter.

impl Eq for GridExtent

impl PartialEq for GridExtent

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for GridExtent