wip: namespaces

crates/app/app_dsl.rs

@@ -0,0 +1,32 @@
+use crate::*;
+
+macro_rules!dsl_sym(
+    (|$state:ident:$State:ty| -> $type:ty {$($lit:literal => $exp:expr),* $(,)?})=>{
+        impl<'t> DslSymNs<'t, $type> for $State {
+            const NS: DslNs<'t, fn (&'t $State)->$type> =
+                DslNs(&[$(($lit, |$state: &$State|$exp)),*]); } });
+
+pub trait DslSymNs<'t, T: 't>: 't {
+    const NS: DslNs<'t, fn (&'t Self)->T>;
+}
+
+pub struct DslNs<'t, T: 't>(pub &'t [(&'t str, T)]);
+
+pub type DslCb = fn (&App) -> Box<dyn Render<TuiOut>>;
+
+impl<'t, D: Dsl> std::ops::Index<D> for DslNs<'t, DslCb> {
+    type Output = DslCb;
+    fn index (&self, index: D) -> &Self::Output {
+        if let Ok(Some(symbol)) = index.src() {
+            for (key, value) in self.0.iter() {
+                if symbol == *key {
+                    return value
+                }
+            }
+        }
+        &(view_nil as DslCb)
+    }
+}
+fn view_nil (_: &App) -> Box<dyn Render<TuiOut>> {
+    Box::new(Fill::xy("·"))
+}