Finally figured out how I want atoms to work

orchid-extension/src/system.rs

@@ -1,6 +1,53 @@
-use orchid_api::expr::Expr;
+use std::any::Any;
+use std::io::{Read, Write};
 
-pub trait System: Send {
-  fn consts(&self) -> Expr;
+use orchid_api::expr::ExprTicket;
+use orchid_api::tree::TreeModule;
+use typeid::ConstTypeId;
+
+use crate::atom::AtomInfo;
+use crate::expr::GenClause;
+use crate::fs::DeclFs;
+use crate::lexer::LexerObj;
+
+/// System as consumed by foreign code
+pub trait SystemCard: Default + Send + Sync + 'static {
+  const NAME: &'static str;
+  const ATOM_DEFS: &'static [Option<AtomInfo>];
 }
 
+pub trait DynSystemCard: Send + Sync + 'static {
+  fn name(&self) -> &'static str;
+  fn atoms(&self) -> &'static [Option<AtomInfo>];
+  fn atom_info_for(&self, tid: ConstTypeId) -> Option<(usize, &AtomInfo)> {
+    (self.atoms().iter().enumerate())
+      .filter_map(|(i, o)| o.as_ref().map(|a| (i, a)))
+      .find(|ent| ent.1.tid == tid)
+  }
+}
+
+impl<T: SystemCard> DynSystemCard for T {
+  fn name(&self) -> &'static str { Self::NAME }
+  fn atoms(&self) -> &'static [Option<AtomInfo>] { Self::ATOM_DEFS }
+}
+
+/// System as defined by author
+pub trait System: Send + Sync + SystemCard {
+  fn env() -> TreeModule;
+  fn source() -> DeclFs;
+  const LEXERS: &'static [LexerObj];
+}
+
+pub trait DynSystem: Send + Sync + 'static {
+  fn env(&self) -> TreeModule;
+  fn source(&self) -> DeclFs;
+  fn lexers(&self) -> &'static [LexerObj];
+  fn card(&self) -> &dyn DynSystemCard;
+}
+
+impl<T: System> DynSystem for T {
+  fn env(&self) -> TreeModule { <Self as System>::env() }
+  fn source(&self) -> DeclFs { <Self as System>::source() }
+  fn lexers(&self) -> &'static [LexerObj] { Self::LEXERS }
+  fn card(&self) -> &dyn DynSystemCard { self }
+}