Struct Scope

pub struct Scope { /* private fields */ }

Scope define the evaluation context/scope that an expression uses when being evaluated. There is a special Identifier (Identity) which is used to bind the initial array being evaluated

Other identifier can be bound with variables either before execution or while executing (see Let). Values can be extracted from the scope using the Var expression.

<let x = lit(1) in var(Identifier::Identity) + var(x), { Identity -> Primitive[1,2,3]> ->
<var(Identifier::Identity) + var(x), { Identity -> Primitive[1,2,3], x -> ConstantArray(1)> ->
<Primitive[1,2,3] + var(x), { Identity -> Primitive[1,2,3], x -> ConstantArray(1)> ->
<Primitive[1,2,3] + ConstantArray(1), { Identity -> Primitive[1,2,3], x -> ConstantArray(1)> ->
<Primitive[2,3,4], { Identity -> Primitive[1,2,3], x -> ConstantArray(1)>

Other values can be bound before execution e.g. <var("x") + var("y") + var("z"), x -> ..., y -> ..., z -> ...>

Implementations

impl Scope

pub fn new(root: ArrayRef) -> Self

Create a new scope with the given root array.

pub fn empty(len: usize) -> Self

Create a new scope with the root array set an empty struct.

pub fn root(&self) -> &ArrayRef

Return the root array of the scope.

pub fn with_scope_var<V: ScopeVar>(self, var: V) -> Self

Returns a new evaluation scope with the given variable applied.

pub fn scope_var<V: ScopeVar>(&self) -> Option<&V>

Returns the scope variable of type V if it exists.

pub fn scope_var_mut<V: ScopeVar>(&mut self) -> Option<&mut V>

Returns the mutable scope variable of type V if it exists.

Trait Implementations

impl Clone for Scope

fn clone(&self) -> Scope

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Deref for Scope

type Target = Arc<dyn Array>

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl From<Arc<dyn Array>> for Scope

fn from(value: ArrayRef) -> Self

Converts to this type from the input type.