Crate zng_var 

Batch updated variables in an app context.

Crate

This crate is part of the zng project.

Cargo Features

This crate provides 3 feature flags, 1 enabled by default.

"debug_default"

Signal the build script to enable the more features in debug builds.

Enabled by default.

"type_names"

Add value_type_name method to get the diagnostics type name from variable values.

"dyn_closure"

Box closures at opportune places, such as Var::map, reducing the number of monomorphised types.

This speeds-up compilation time at the cost of runtime.

Modules

animation

Var animation types and functions.

Macros

__context_var_local

Declares new app and context local variable.

context_var

Declares new ContextVar<T> static items.

expr_var

New variable from an expression with interpolated vars.

impl_from_and_into_var

Implements T: IntoVar<U>, T: IntoValue<U> and optionally U: From<T> without boilerplate.

merge_var

Initializes a new Var<T> with value made by merging multiple other variables.

when_var

Initializes a new conditional var.

Structs

AnyVar

Variable of any type.

AnyVarHookArgs

Arguments for AnyVar::hook.

AnyVarModify

Mutable reference to a variable value.

AnyWhenVarBuilder

Type erased when_var! manual builder.

ArcEq

Arc value that implements equality by pointer comparison.

BoxAnyVarValue

Small box for AnyVarValue values.

ContextInitHandle

Identifies the unique context a contextual_var is in.

ContextVar

Represents a named contextual variable.

MergeVarBuilder

Build a merge_var! from any number of input vars of the same type I.

ObservableVec

Represents a Vec<T> that tracks changes when used inside a variable.

ResponderVar

Represents a read-write variable used to notify the completion of an async operation.

ResponseVar

Represents a read-only variable used to listen to a one time signal that an async operation has completed.

VARS

Variable updates and animation service.

VARS_APP

VARS APP integration.

Var

Variable of type T.

VarCapability

Kinds of interactions allowed by a Var<T> in the current update.

VarEq

Represents a Var<T> as a value inside another variable.

VarHandle

Handle to a variable or animation hook.

VarHandles

Represents a collection of var handles.

VarHookArgs

Arguments for Var::hook.

VarInstanceTag

Unique identifier of a share variable, while it is alive.

VarIsReadOnlyError

Error when an attempt to modify a variable without the MODIFY capability is made.

VarMergeInputs

Input arguments for the merge closure of MergeVarBuilder merge vars.

VarModify

Mutable reference to a variable value.

VarUpdateId

Represents the last time a variable was mutated or the current update cycle.

WeakAnyVar

Weak reference to a AnyVar.

WeakContextInitHandle

Weak ContextInitHandle.

WeakVar

Weak reference to a Var<T>.

WhenVarBuilder

Manual when_var! builder.

Enums

Response

Raw value in a ResponseVar.

VecChange

Represents a change in a ObservableVec.

Traits

AnyVarValue

Represents any variable value.

IntoValue

A property value that is not a variable but can be inspected.

IntoVar

A value-to-var conversion that consumes the value.

VarValue

Represents a type that can be a Var<T> value.

Functions

any_const_var

Type erased const_var.

any_contextual_var

Create a type erased contextualized variable.

any_var

New read/write shared reference type-erased variable.

any_var_derived

New read/write shared reference type-erased variable that has initial value derived from source.

const_var

New immutable variable that stores the value directly.

contextual_var

Create a contextualized variable.

response_done_var

New ResponseVar in the done state.

response_var

New paired ResponderVar and ResponseVar in the waiting state.

var

New read/write shared reference variable.

var_default

New read/write shared reference variable with default initial value.

var_derived

New read/write shared reference type-erased variable that has initial value derived from source.

var_from

New read/write shared reference variable from any type that can convert into it.

var_getter

Variable for getter properties (get_*, actual_*).

var_state

Variable for state properties (is_*, has_*).

weak_var

Weak variable that never upgrades.

weak_var_any

Weak variable that never upgrades.