Add Value type and replace dyn-nodes with call-exprs 🏗

- In addition to syntax trees there are now `Value`s, which syntax trees can be evaluated into (e.g. the tree is `5+5` and the value is `10`)
- Parsing is completely pure, function calls are not parsed into nodes, but into simple call expressions, which are resolved later
- Functions aren't dynamic nodes anymore, but simply functions which receive their arguments as a table and the layouting context
- Functions may return any `Value`
- Layouting is powered by functions which return the new `Commands` value, which informs the layouting engine what to do
- When a function returns a non-`Commands` value, the layouter simply dumps the value into the document in monospace

1 files changed, 22 insertions, 38 deletions

diff --git a/src/library/boxed.rs b/src/library/boxed.rs
index 3637f072..c03043ae 100644
--- a/src/library/boxed.rs
+++ b/src/library/boxed.rs
@@ -6,48 +6,32 @@ use super::*;
 /// # Keyword arguments
 /// - `width`: The width of the box (length of relative to parent's width).
 /// - `height`: The height of the box (length of relative to parent's height).
-pub fn boxed(call: FuncCall, _: &ParseState) -> Pass<SyntaxNode> {
+pub async fn boxed(mut args: TableValue, mut ctx: LayoutContext<'_>) -> Pass<Value> {
     let mut f = Feedback::new();
-    let mut args = call.args;
-    let node = BoxNode {
-        content: args.take::<SyntaxTree>().unwrap_or(SyntaxTree::new()),
-        width: args.take_with_key::<_, ScaleLength>("width", &mut f),
-        height: args.take_with_key::<_, ScaleLength>("height", &mut f),
-    };
+    let content = args.take::<SyntaxTree>().unwrap_or(SyntaxTree::new());
+    let width = args.take_with_key::<_, ScaleLength>("width", &mut f);
+    let height = args.take_with_key::<_, ScaleLength>("height", &mut f);
     args.unexpected(&mut f);
-    Pass::node(node, f)
-}
-
-#[derive(Debug, Clone, PartialEq)]
-struct BoxNode {
-    content: SyntaxTree,
-    width: Option<ScaleLength>,
-    height: Option<ScaleLength>,
-}
 
-#[async_trait(?Send)]
-impl Layout for BoxNode {
-    async fn layout<'a>(&'a self, mut ctx: LayoutContext<'_>) -> Pass<Commands<'a>> {
-        ctx.spaces.truncate(1);
-        ctx.repeat = false;
+    ctx.spaces.truncate(1);
+    ctx.repeat = false;
 
-        self.width.with(|v| {
-            let length = v.raw_scaled(ctx.base.x);
-            ctx.base.x = length;
-            ctx.spaces[0].size.x = length;
-            ctx.spaces[0].expansion.horizontal = true;
-        });
+    width.with(|v| {
+        let length = v.raw_scaled(ctx.base.x);
+        ctx.base.x = length;
+        ctx.spaces[0].size.x = length;
+        ctx.spaces[0].expansion.horizontal = true;
+    });
 
-        self.height.with(|v| {
-            let length = v.raw_scaled(ctx.base.y);
-            ctx.base.y = length;
-            ctx.spaces[0].size.y = length;
-            ctx.spaces[0].expansion.vertical = true;
-        });
+    height.with(|v| {
+        let length = v.raw_scaled(ctx.base.y);
+        ctx.base.y = length;
+        ctx.spaces[0].size.y = length;
+        ctx.spaces[0].expansion.vertical = true;
+    });
 
-        layout(&self.content, ctx).await.map(|out| {
-            let layout = out.into_iter().next().unwrap();
-            vec![Add(layout)]
-        })
-    }
+    let layouted = layout(&content, ctx).await;
+    let layout = layouted.output.into_iter().next().unwrap();
+    f.extend(layouted.feedback);
+    Pass::commands(vec![Add(layout)], f)
 }