Enum DataSource 

pub enum DataSource {
    Scan {
        relation: NameId,
        vars: Vec<NameId>,
    },
    ScanDelta {
        relation: NameId,
        vars: Vec<NameId>,
    },
    IndexLookup {
        relation: NameId,
        col_idx: usize,
        key: Operand,
        vars: Vec<NameId>,
    },
}

Variants

Scan

Scan a relation (iterate over all tuples). Binds the variables in vars to the columns of the relation.

Fields

relation: NameId

vars: Vec<NameId>

ScanDelta

Scan only the “delta” set of a relation (new facts from last iteration).

Fields

relation: NameId

vars: Vec<NameId>

IndexLookup

Lookup in an index. col_idx: The column index to lookup on. key: The value to look up. vars: Variables to bind to the other columns (or all columns?). For simplicity: vars maps to the relation columns. The column at col_idx is already bound (to key), but we might re-bind it or check it.

Fields

relation: NameId

col_idx: usize

key: Operand

vars: Vec<NameId>

Trait Implementations

impl Clone for DataSource

fn clone(&self) -> DataSource

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DataSource

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

Formats the value using the given formatter.

impl PartialEq for DataSource

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for DataSource