Struct mz_sql::plan::expr::WindowExpr

pub struct WindowExpr {
    pub func: WindowExprType,
    pub partition_by: Vec<HirScalarExpr>,
    pub order_by: Vec<HirScalarExpr>,
}

Represents the invocation of a window function over an optional partitioning with an optional order.

Fields

func: WindowExprType

partition_by: Vec<HirScalarExpr>

order_by: Vec<HirScalarExpr>

ORDER BY is represented in a complicated way: plan_function_order_by gave us two things:

• the ColumnOrders we have put in the order_by fields in the WindowExprType in func above,
• the HirScalarExprs we have put in the following order_by field. These are separated because they are used in different places: the outer order_by is used in the lowering: based on it, we create a Row constructor that collects the scalar exprs; the inner order_by is used in the rendering to actually execute the ordering on these Rows. (WindowExpr exists only in HIR, but not in MIR.) Note that the column field in the ColumnOrders point into the Row constructed in the lowering, and not to original input columns.

Implementations

impl WindowExpr

pub fn visit_expressions<'a, F, E>(&'a self, f: &mut F) -> Result<(), E>

where F: FnMut(&'a HirScalarExpr) -> Result<(), E>,

pub fn visit_expressions_mut<'a, F, E>(&'a mut self, f: &mut F) -> Result<(), E>

where F: FnMut(&'a mut HirScalarExpr) -> Result<(), E>,

Trait Implementations

impl Clone for WindowExpr

fn clone(&self) -> WindowExpr

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for WindowExpr

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for WindowExpr

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Hash for WindowExpr

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

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 Ord for WindowExpr

fn cmp(&self, other: &WindowExpr) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl PartialEq for WindowExpr

fn eq(&self, other: &WindowExpr) -> 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 PartialOrd for WindowExpr

fn partial_cmp(&self, other: &WindowExpr) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Serialize for WindowExpr

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl VisitChildren<HirScalarExpr> for WindowExpr

fn visit_children<F>(&self, f: F)

where F: FnMut(&HirScalarExpr),

Apply an infallible immutable function f to each direct child.

fn visit_mut_children<F>(&mut self, f: F)

where F: FnMut(&mut HirScalarExpr),

Apply an infallible mutable function f to each direct child.

fn try_visit_children<F, E>(&self, f: F) -> Result<(), E>

where F: FnMut(&HirScalarExpr) -> Result<(), E>, E: From<RecursionLimitError>,

Apply a fallible immutable function f to each direct child.

fn try_visit_mut_children<F, E>(&mut self, f: F) -> Result<(), E>

where F: FnMut(&mut HirScalarExpr) -> Result<(), E>, E: From<RecursionLimitError>,

Apply a fallible mutable function f to each direct child.

impl Eq for WindowExpr

impl StructuralPartialEq for WindowExpr