well, it compiles. fails on run, though

This commit is contained in:
🪞👃🪞 2025-01-18 16:32:04 +01:00
parent a362028ae7
commit d14d67172c
6 changed files with 96 additions and 185 deletions

View file

@ -1,28 +1,25 @@
use crate::*;
use std::{sync::Arc, fmt::Debug};
use Value::*;
/// Define an EDN-backed view.
///
/// This consists of:
/// * render callback (implementation of [Content])
/// * value providers (implementations of [Context])
#[macro_export] macro_rules! view {
($Output:ty: |$self:ident: $App:ty| $content:expr $(;{
$( $type:ty { $($sym:literal => $value:expr),* } );*
})?) => {
impl Content<$Output> for $App {
fn content(&$self) -> impl Render<$Output> { $content }
($Output:ty: |$self:ident: $State:ty| $expr:expr; {
$($sym:literal => $body:expr),* $(,)?
}) => {
impl Content<$Output> for $State {
fn content (&$self) -> impl Render<$Output> { $expr }
}
$($(
impl Context<$type> for $App {
fn get (&$self, atom: &Value) -> Option<$type> {
Some(match atom.to_ref() { $(Atom::Sym($sym) => $value,)* _ => return None })
impl<'a> ViewContext<'a, $Output> for $State {
fn get_content_custom (&'a $self, value: &Value<'a>) -> Option<RenderBox<'a, $Output>> {
if let Value::Sym(s) = value {
match *s { $($sym => Some($body),)* _ => None }
} else {
panic!("expected symbol")
}
}
)*)?
}
}
}
// An ephemeral wrapper around view state and view description,
// that is meant to be constructed and returned from [Content::content].
pub struct View<'a, T>(pub &'a T, pub TokenIter<'a>);
impl<'a, O: Output + 'a, T: ViewContext<'a, O>> Content<O> for View<'a, T> {
fn content (&self) -> impl Render<O> {
@ -35,97 +32,36 @@ impl<'a, O: Output + 'a, T: ViewContext<'a, O>> Content<O> for View<'a, T> {
return None
}
}
/// Renders from EDN source and context.
///
/// Generic over:
///
/// * `O` - Output target.
/// * `S` - State provider.
/// * `A` - Atom storage type.
#[derive(Default, Clone)] pub enum AtomView<'a, O, S, A> {
_Unused(std::marker::PhantomData<&'a O>),
#[default] Inert,
Src(S, &'a str),
Ref(S, &'a A),
Own(S, A),
Err(Arc<str>)
}
impl<'a, O, S, A> Debug for AtomView<'a, O, S, A>
where S: Debug, A: Debug {
fn fmt (&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
match self {
Self::Inert =>
write!(f, "AtomView::Inert"),
Self::Src(state, view) =>
write!(f, "AtomView::Src(state={state:?} view={view:?}"),
Self::Ref(state, view) =>
write!(f, "AtomView::Ref(state={state:?} view={view:?}"),
Self::Own(state, view) =>
write!(f, "AtomView::Arc(state={state:?} view={view:?}"),
Self::Err(error) =>
write!(f, "AtomView::Err({error})"),
_ => unreachable!()
}
}
}
impl<'a, O, S, A> Content<O> for AtomView<'a, O, S, A>
where O: Output, S: ViewContext<'a, O>, A: Send + Sync {
fn content (&self) -> impl Render<O> {
match self {
Self::Inert => { panic!("inert rendered") },
Self::Err(e) => { panic!("render error: {e}") },
Self::Src(state, source) => {},
Self::Ref(state, atom) => {},
Self::Own(state, atom) => {},
_ => unreachable!()
}
}
}
impl<'a, E: Output, T> ViewContext<'a, E> for T where T: Sized + Send + Sync
// Provides components to the view.
pub trait ViewContext<'a, E: Output + 'a>: Send + Sync
+ Context<bool>
+ Context<usize>
+ Context<E::Unit>
+ Context<Box<dyn Render<E> + 'a>> {}
/// Provides values to the template
pub trait ViewContext<'a, E: Output>: Sized + Send + Sync
+ Context<bool>
+ Context<usize>
+ Context<E::Unit>
+ Context<Box<dyn Render<E> + 'a>>
{
fn get_bool (&self, atom: &Value) -> Option<bool> {
Some(match atom {
Num(n) => match *n { 0 => false, _ => true },
Sym(x) => match *x {
":false" | ":f" => false, ":true" | ":t" => true,
_ => return Context::get(self, atom)
},
_ => return Context::get(self, atom)
})
fn get_content (&'a self, value: &Value<'a>) -> Option<RenderBox<'a, E>> {
if let Some(builtin) = self.get_content_builtin(value) {
Some(builtin)
} else {
self.get_content_custom(value)
}
}
fn get_usize (&self, atom: &Value) -> Option<usize> {
Some(match atom {Num(n) => *n, _ => return Context::get(self, atom)})
}
fn get_unit (&self, atom: &Value) -> Option<E::Unit> {
Some(match atom {Num(n) => E::Unit::from(*n as u16), _ => return Context::get(self, atom)})
}
fn get_content (&self, atom: &Value) -> Option<Box<dyn Render<E> + 'a>> where E: 'a {
try_delegate!(self, *atom, When::<RenderBox<'a, E>>);
try_delegate!(self, *atom, Either::<RenderBox<'a, E>, RenderBox<'a, E>>);
try_delegate!(self, *atom, Align::<RenderBox<'a, E>>);
try_delegate!(self, *atom, Bsp::<RenderBox<'a, E>, RenderBox<'a, E>>);
try_delegate!(self, *atom, Fill::<RenderBox<'a, E>>);
try_delegate!(self, *atom, Fixed::<_, RenderBox<'a, E>>);
try_delegate!(self, *atom, Min::<_, RenderBox<'a, E>>);
try_delegate!(self, *atom, Max::<_, RenderBox<'a, E>>);
try_delegate!(self, *atom, Shrink::<_, RenderBox<'a, E>>);
try_delegate!(self, *atom, Expand::<_, RenderBox<'a, E>>);
try_delegate!(self, *atom, Push::<_, RenderBox<'a, E>>);
try_delegate!(self, *atom, Pull::<_, RenderBox<'a, E>>);
try_delegate!(self, *atom, Margin::<_, RenderBox<'a, E>>);
try_delegate!(self, *atom, Padding::<_, RenderBox<'a, E>>);
Some(Context::get_or_fail(self, atom))
fn get_content_custom (&'a self, value: &Value<'a>) -> Option<RenderBox<'a, E>>;
fn get_content_builtin (&'a self, value: &Value<'a>) -> Option<RenderBox<'a, E>> {
try_delegate!(self, *value, When::<RenderBox<'a, E>>);
try_delegate!(self, *value, Either::<RenderBox<'a, E>, RenderBox<'a, E>>);
try_delegate!(self, *value, Align::<RenderBox<'a, E>>);
try_delegate!(self, *value, Bsp::<RenderBox<'a, E>, RenderBox<'a, E>>);
try_delegate!(self, *value, Fill::<RenderBox<'a, E>>);
try_delegate!(self, *value, Fixed::<_, RenderBox<'a, E>>);
try_delegate!(self, *value, Min::<_, RenderBox<'a, E>>);
try_delegate!(self, *value, Max::<_, RenderBox<'a, E>>);
try_delegate!(self, *value, Shrink::<_, RenderBox<'a, E>>);
try_delegate!(self, *value, Expand::<_, RenderBox<'a, E>>);
try_delegate!(self, *value, Push::<_, RenderBox<'a, E>>);
try_delegate!(self, *value, Pull::<_, RenderBox<'a, E>>);
try_delegate!(self, *value, Margin::<_, RenderBox<'a, E>>);
try_delegate!(self, *value, Padding::<_, RenderBox<'a, E>>);
None
}
}
#[macro_export] macro_rules! try_delegate {
@ -135,17 +71,10 @@ pub trait ViewContext<'a, E: Output>: Sized + Send + Sync
}
}
}
// A function that returns a `RenderBox.
pub type AtomCallback<'a, O, State> =
dyn Fn(&'a State)-> RenderBox<'a, O> + Send + Sync + 'a;
// A box containing a function that returns a `RenderBox.
pub type AtomRenderCallback<'a, O, State> =
Box<AtomCallback<'a, O, State>>;
#[macro_export] macro_rules! try_from_expr {
(<$l:lifetime, $E:ident>: $Struct:ty: |$state:ident, $atoms:ident|$body:expr) => {
impl<$l, $E: Output + $l, T: ViewContext<$l, $E>> TryFromAtom<T> for $Struct {
fn try_from_atom ($state: &T, atom: Value) -> Option<Self> {
impl<$l, $E: Output + $l, T: ViewContext<$l, $E>> TryFromAtom<$l, T> for $Struct {
fn try_from_atom ($state: &$l T, atom: Value<$l>) -> Option<Self> {
if let Value::Exp(0, $atoms) = atom {
$body;
}
@ -154,28 +83,3 @@ pub type AtomRenderCallback<'a, O, State> =
}
}
}
/// Implement `Context` for a context and content type.
///
/// This enables support for layout expressions.
#[macro_export] macro_rules! provide_content {
(|$self:ident:$State:ty|{ $($pat:pat => $expr:expr),* $(,)? }) => {
impl<E: Output> Context<Box<dyn Render<E> + '_>> for $State {
fn get (&$self, atom: &Value) -> Option<Box<dyn Render<E> + '_>> {
Some(match atom {
$(Value::Sym($pat) => $expr,)*
_ => return None
})
}
}
};
($Output:ty: |$self:ident:$State:ty|{ $($pat:pat => $expr:expr),* $(,)? }) => {
impl Context<Box<dyn Render<$Output> + '_>> for $State {
fn get (&$self, atom: &Value) -> Option<Box<dyn Render<$Output> + '_>> {
Some(match atom {
$(Value::Sym($pat) => $expr,)*
_ => return None
})
}
}
}
}