Struct mz_sql::plan::lowering::ColumnMap

struct ColumnMap {
    inner: BTreeMap<ColumnRef, usize>,
}

Maps a leveled column reference to a specific column.

Leveled column references are nested, so that larger levels are found early in a record and level zero is found at the end.

The column map only stores references for levels greater than zero, and column references at level zero simply start at the first column after all prior references.

Fields

inner: BTreeMap<ColumnRef, usize>

Implementations

impl ColumnMap

fn empty() -> ColumnMap

fn new(inner: BTreeMap<ColumnRef, usize>) -> ColumnMap

fn get(&self, col_ref: &ColumnRef) -> usize

fn len(&self) -> usize

fn enter_scope(&self, arity: usize) -> ColumnMap

Updates references in the ColumnMap for use in a nested scope. The provided arity must specify the arity of the current scope.

Trait Implementations

impl Clone for ColumnMap

fn clone(&self) -> ColumnMap

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ColumnMap

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

Formats the value using the given formatter.