Struct EvalSession 

pub struct EvalSession<'a> {
    pub params: &'a Params,
    pub symbols: &'a SymbolTable,
    pub functions: &'a Functions,
    pub runtime_context: &'a RuntimeContext,
    pub arena: Option<&'a QueryArena>,
    pub identity: IdentityId,
    pub is_aggregate_context: bool,
}

Session-scoped evaluation context — holds the 7 fields that are invariant within a given operator. Provides factory methods to produce EvalContext values that vary only in columns and row_count.

Fields

params: &'a Params

symbols: &'a SymbolTable

functions: &'a Functions

runtime_context: &'a RuntimeContext

arena: Option<&'a QueryArena>

identity: IdentityId

is_aggregate_context: bool

Implementations

impl<'a> EvalSession<'a>

pub fn eval(&self, columns: Columns, row_count: usize) -> EvalContext<'a>

Main constructor — produces an EvalContext with target=None and take=None.

pub fn eval_empty(&self) -> EvalContext<'a>

Shorthand for eval(Columns::empty(), 1).

pub fn eval_join(&self, columns: Columns) -> EvalContext<'a>

Shorthand for eval(columns, 1) with take=Some(1).

pub fn from_transform( ctx: &'a TransformContext<'_>, stored: &'a QueryContext, ) -> Self

Build from a TransformContext + stored QueryContext (volcano nodes with input).

pub fn from_query(ctx: &'a QueryContext) -> Self

Build from a QueryContext (without-input nodes, joins, inline).

pub fn testing() -> EvalSession<'static>

Build a testing session with static empty values.

Trait Implementations

impl<'a> Clone for EvalSession<'a>

fn clone(&self) -> EvalSession<'a>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Copy for EvalSession<'a>