I don't know what I was doing here but I probably won't return to this branch anyway

rust/src/lib.rs

@@ -1 +1,2 @@
 pub mod gg;
+pub mod vm;

rust/src/vm.rs

@@ -0,0 +1,54 @@
+
+use super::gg;
+use std::collections::HashMap;
+
+pub enum Error{
+    FunctionFromGraph(String),
+}
+
+enum ResolvedValue<'a> {
+    Value(gg::Value),
+    Function(&'a dyn Fn(gg::Value) -> gg::Value),
+}
+
+struct Scope<'a> {
+    parent: Option<&'a Scope<'a>>,
+    values: HashMap<&'a str, ResolvedValue<'a>>,
+}
+
+impl<'a> Scope<'a> {
+
+    fn new(parent: Option<&'a Scope<'a>>) -> Scope<'a> {
+        Scope {
+            parent: parent,
+            values: HashMap::new(),
+        }
+    }
+
+    fn resolve(&self, name: &str) -> Option<&ResolvedValue> {
+
+        if let Some(rval) = self.values.get(name) {
+            Some(rval)
+
+        } else if let Some(parent) = self.parent {
+            parent.resolve(name)
+
+        } else {
+            None
+        }
+    }
+
+    fn insert(&mut self, name: &'a str, rval: ResolvedValue<'a>) {
+        self.values.insert(name, rval);
+    }
+}
+
+fn always(value: gg::Value) -> Box<dyn Fn(gg::Value) -> gg::Value> {
+    Box::new(move |_: gg::Value| value)
+}
+
+//fn function_from_graph<'a>(
+//    scope: &'a Scope<'a>, g: gg::Graph,
+//) -> Result<&'a dyn Fn(gg::Value) -> gg::Value, Error> {
+//
+//}