fission-core
v0.10.0
Core runtime, state, actions, effects, resources, input, and UI model for Fission
Install
cargo add fission-core
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Platform support
Declared by the crate author and captured when this directory was generated.
Android
Supported
iOS
Supported
Linux
Supported
macOS
Supported
Windows
Supported
Web
Supported
Terminal
Supported
Static site
Supported
Server-rendered
Supported
Package metadata
crates.io
View package
Documentation
Not provided
Repository
Open link
License
MIT
Latest version
0.10.0
Downloads
1698
Last updated
2026-08-02T15:16:26.787059Z
Categories
gui
rendering
Keywords
cross-platform
fission
runtime
state-management
ui-framework
Published versions
0.10.0
0.9.2
0.9.1
0.9.0
0.8.0
0.7.0
0.6.3
0.6.2
0.6.1
0.6.0
0.5.1
0.5.0
Dependencies
Dependency metadata is not indexed yet.
README
fission-core
The runtime, widget system, and action/reducer architecture for the Fission UI framework.
fission-core is the central crate of the Fission toolkit. It provides the declarative widget tree,
the unidirectional data-flow architecture (actions, reducers, effects), and the runtime that
ties everything together. Applications describe their UI as a Widget tree built from composable
widgets, dispatch Action values to modify GlobalState, and let the runtime lower the tree into
the intermediate representation consumed by platform renderers.
Architecture overview
From<Component> Runtime::dispatch()
| |
ViewHandle<S> + BuildCtxHandle<S> ActionEnvelope
| |
Widget tree Reducer(s)
| |
internal lowering mutate GlobalState
| + emit Effects
CoreIR (fission-ir) |
| EffectEnvelope
LayoutEngine |
| Platform executor
Renderer
1.
Widget layer -- From<Component> for Widget builds the authored tree. Components that need state or action wiring request scoped ViewHandle<S> and BuildCtxHandle<S> values through fission::build::current::<S>().
2.
Internal lowering -- Fission converts Widget values into fission-ir operations
(paint ops, layout ops, semantics). This is not part of normal application authoring.
3.
Layout -- fission-layout resolves flex, grid, scroll, and absolute positioning.
4.
Rendering -- Platform backends (Metal, Skia, HTML Canvas) consume the laid-out IR.
5.
Actions -- User interactions produce ActionEnvelope values that the Runtimedispatches to registered reducers.
6.
Reducers -- Pure functions that mutate GlobalState and optionally emit side-effects
through Effects.
7.
Effects -- Asynchronous operations (HTTP, file I/O, alerts) that the platform
executor runs outside the deterministic core.
Key concepts
GlobalState
Any Send + Sync + Debug + 'static type that implements GlobalState. The runtime stores
one instance per concrete type.
Action / ActionEnvelope
Action is a trait for strongly-typed, serialisable event payloads. Actions are transported
as ActionEnvelope (type-erased ID + JSON bytes) so the reducer pipeline stays generic.
BuildCtxHandle
The scoped context handle available during authoring conversion. Use it to:
•
Bind actions to handlers: with_reducer!(ctx, MyAction { .. }, my_handler) or #[fission_reducer(MyAction)] for compact one-reducer actions
•
Register portals (overlays, modals, toasts)
•
Request animations
ViewHandle
Read-only scoped access to GlobalState, the current theme, i18n registry, layout snapshot, and
animation values.
Widget
The closed authored widget tree carrier. It has one variant per built-in widget such as Button, Text, Row, and Column; application components produce it with impl From<Component> for Widget.
Effects
Reducers that need async work (network, disk, timers) push EffectEnvelope values throughEffects. The platform executor fulfils them and dispatches the on_ok / on_err callbacks
back into the action pipeline.
Quick example
use fission::prelude::*;
// 1. Define state
#[derive(Debug, Default)]
struct Counter { count: i32 }
impl GlobalState for Counter {}
// 2. Define a reducer. This also generates the Increment action.
#[fission_reducer(Increment)]
fn handle_increment(state: &mut Counter) {
state.count += 1;
}
// 3. Build the widget tree
struct CounterWidget;
impl From<CounterWidget> for Widget {
fn from(_: CounterWidget) -> Self {
let (ctx, view) = fission::build::current::<Counter>();
let on_press = with_reducer!(ctx, Increment, handle_increment);
Column {
children: vec![
Text::new(format!("Count: {}", view.state().count)).into(),
Button {
child: Some(Text::new("Add one").into()),
on_press: Some(on_press),
..Default::default()
}.into(),
],
..Default::default()
}.into()
}
}
Crate feature flags
None at this time -- all functionality is included by default.
License
MIT
README
fission-core
The runtime, widget system, and action/reducer architecture for the Fission UI framework.
fission-core is the central crate of the Fission toolkit. It provides the declarative widget tree,
the unidirectional data-flow architecture (actions, reducers, effects), and the runtime that
ties everything together. Applications describe their UI as a Widget tree built from composable
widgets, dispatch Action values to modify GlobalState, and let the runtime lower the tree into
the intermediate representation consumed by platform renderers.
Architecture overview
From<Component> Runtime::dispatch()
| |
ViewHandle<S> + BuildCtxHandle<S> ActionEnvelope
| |
Widget tree Reducer(s)
| |
internal lowering mutate GlobalState
| + emit Effects
CoreIR (fission-ir) |
| EffectEnvelope
LayoutEngine |
| Platform executor
Renderer
1.
Widget layer -- From<Component> for Widget builds the authored tree. Components that need state or action wiring request scoped ViewHandle<S> and BuildCtxHandle<S> values through fission::build::current::<S>().
2.
Internal lowering -- Fission converts Widget values into fission-ir operations
(paint ops, layout ops, semantics). This is not part of normal application authoring.
3.
Layout -- fission-layout resolves flex, grid, scroll, and absolute positioning.
4.
Rendering -- Platform backends (Metal, Skia, HTML Canvas) consume the laid-out IR.
5.
Actions -- User interactions produce ActionEnvelope values that the Runtimedispatches to registered reducers.
6.
Reducers -- Pure functions that mutate GlobalState and optionally emit side-effects
through Effects.
7.
Effects -- Asynchronous operations (HTTP, file I/O, alerts) that the platform
executor runs outside the deterministic core.
Key concepts
GlobalState
Any Send + Sync + Debug + 'static type that implements GlobalState. The runtime stores
one instance per concrete type.
Action / ActionEnvelope
Action is a trait for strongly-typed, serialisable event payloads. Actions are transported
as ActionEnvelope (type-erased ID + JSON bytes) so the reducer pipeline stays generic.
BuildCtxHandle
The scoped context handle available during authoring conversion. Use it to:
•
Bind actions to handlers: with_reducer!(ctx, MyAction { .. }, my_handler) or #[fission_reducer(MyAction)] for compact one-reducer actions
•
Register portals (overlays, modals, toasts)
•
Request animations
ViewHandle
Read-only scoped access to GlobalState, the current theme, i18n registry, layout snapshot, and
animation values.
Widget
The closed authored widget tree carrier. It has one variant per built-in widget such as Button, Text, Row, and Column; application components produce it with impl From<Component> for Widget.
Effects
Reducers that need async work (network, disk, timers) push EffectEnvelope values throughEffects. The platform executor fulfils them and dispatches the on_ok / on_err callbacks
back into the action pipeline.
Quick example
use fission::prelude::*;
// 1. Define state
#[derive(Debug, Default)]
struct Counter { count: i32 }
impl GlobalState for Counter {}
// 2. Define a reducer. This also generates the Increment action.
#[fission_reducer(Increment)]
fn handle_increment(state: &mut Counter) {
state.count += 1;
}
// 3. Build the widget tree
struct CounterWidget;
impl From<CounterWidget> for Widget {
fn from(_: CounterWidget) -> Self {
let (ctx, view) = fission::build::current::<Counter>();
let on_press = with_reducer!(ctx, Increment, handle_increment);
Column {
children: vec![
Text::new(format!("Count: {}", view.state().count)).into(),
Button {
child: Some(Text::new("Add one").into()),
on_press: Some(on_press),
..Default::default()
}.into(),
],
..Default::default()
}.into()
}
}
Crate feature flags
None at this time -- all functionality is included by default.
License
MIT
Package metadata
crates.io
View package
Documentation
Not provided
Repository
Open link
License
MIT
Latest version
0.10.0
Downloads
1698
Last updated
2026-08-02T15:16:26.787059Z
Categories
gui
rendering
Keywords
cross-platform
fission
runtime
state-management
ui-framework
Published versions
0.10.0
0.9.2
0.9.1
0.9.0
0.8.0
0.7.0
0.6.3
0.6.2
0.6.1
0.6.0
0.5.1
0.5.0
Dependencies
Dependency metadata is not indexed yet.