Implement experimental WebGPU support (#1238)

* Web gpu execution MVP

Ready infrastructure for wgpu experimentation

Start implementing simple gpu test case

Fix Extract Node not working with nested networks

Convert inputs for extracted node to network inputs

Fix missing cors headers

Feature gate gcore to make it once again no-std compatible

Add skeleton structure gpu shader

Work on gpu node graph output saving

Fix Get and Set nodes

Fix storage nodes

Fix shader construction errors -> spirv errors

Add unsafe version

Add once cell node

Web gpu execution MVP

node-graph/gcore/src/structural.rs

@@ -39,6 +39,7 @@ pub struct AsyncComposeNode<First, Second, I> {
 	phantom: PhantomData<I>,
 }
 
+#[cfg(feature = "alloc")]
 impl<'i, 'f: 'i, 's: 'i, Input: 'static, First, Second> Node<'i, Input> for AsyncComposeNode<First, Second, Input>
 where
 	First: Node<'i, Input>,
@@ -54,6 +55,7 @@ where
 	}
 }
 
+#[cfg(feature = "alloc")]
 impl<'i, First, Second, Input: 'i> AsyncComposeNode<First, Second, Input>
 where
 	First: Node<'i, Input>,
@@ -77,6 +79,7 @@ pub trait Then<'i, Input: 'i>: Sized {
 
 impl<'i, First: Node<'i, Input>, Input: 'i> Then<'i, Input> for First {}
 
+#[cfg(feature = "alloc")]
 pub trait AndThen<'i, Input: 'i>: Sized {
 	fn and_then<Second>(self, second: Second) -> AsyncComposeNode<Self, Second, Input>
 	where
@@ -88,6 +91,7 @@ pub trait AndThen<'i, Input: 'i>: Sized {
 	}
 }
 
+#[cfg(feature = "alloc")]
 impl<'i, First: Node<'i, Input>, Input: 'i> AndThen<'i, Input> for First {}
 
 pub struct ConsNode<I: From<()>, Root>(pub Root, PhantomData<I>);
@@ -108,6 +112,38 @@ impl<'i, Root: Node<'i, I>, I: 'i + From<()>> ConsNode<I, Root> {
 	}
 }
 
+pub struct ApplyNode<O, N> {
+	pub node: N,
+	_o: PhantomData<O>,
+}
+/*
+#[node_macro::node_fn(ApplyNode)]
+fn apply<In, N>(input: In, node: &'any_input N) -> ()
+where
+	// TODO: try to allows this to return output other than ()
+	N: for<'any_input> Node<'any_input, In, Output = ()>,
+{
+	node.eval(input)
+}
+*/
+impl<'input, In: 'input, N: 'input, S0: 'input, O: 'input> Node<'input, In> for ApplyNode<O, S0>
+where
+	N: Node<'input, In, Output = O>,
+	S0: Node<'input, (), Output = &'input N>,
+{
+	type Output = <N as Node<'input, In>>::Output;
+	#[inline]
+	fn eval(&'input self, input: In) -> Self::Output {
+		let node = self.node.eval(());
+		node.eval(input)
+	}
+}
+impl<'input, S0: 'input, O: 'static> ApplyNode<O, S0> {
+	pub const fn new(node: S0) -> Self {
+		Self { node, _o: PhantomData }
+	}
+}
+
 #[cfg(test)]
 mod test {
 	use crate::{ops::IdNode, value::ValueNode};
@@ -134,4 +170,15 @@ mod test {
 
 		assert_eq!(compose.eval(()), &5);
 	}
+
+	#[test]
+	fn test_apply() {
+		let mut array = [1, 2, 3];
+		let slice = &mut array;
+		let set_node = crate::storage::SetOwnedNode::new(slice);
+
+		let apply = ApplyNode::new(ValueNode::new(set_node));
+
+		assert_eq!(apply.eval((1, 2)), ());
+	}
 }