Struct ExprMap 

pub struct ExprMap {
    pub base: Box<Expr>,
    pub map: Box<Expr>,
}

A map/transform operation over a collection.

ExprMap applies a transformation expression to each item in a base collection. Within the map expression, Expr::arg(n) refers to elements of each item:

• For simple values, arg(0) is the item itself.
• For records, arg(0) is field 0, arg(1) is field 1, etc.

Examples

Simple values

map([1, 2, 3], x => x == field)

Here base is [1, 2, 3] and map is arg(0) == field.

Records

map([{1, 2}, {3, 4}], r => r.0 + r.1)

Here each item is a record with two fields. arg(0) refers to the first field and arg(1) refers to the second field of each record.

Fields

base: Box<Expr>

The collection expression to iterate over.

map: Box<Expr>

The transformation to apply to each item. Use Expr::arg(n) to reference elements of the current item being mapped.

Trait Implementations

impl Clone for ExprMap

fn clone(&self) -> ExprMap

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ExprMap

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

Formats the value using the given formatter.

impl From<ExprMap> for Expr

fn from(value: ExprMap) -> Expr

Converts to this type from the input type.

impl PartialEq for ExprMap

fn eq(&self, other: &ExprMap) -> 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 ExprMap