Initial commit

src/fn_register.rs

@@ -0,0 +1,57 @@
+use std::any::Any;
+use std::boxed::Box;
+
+use engine::{EvalError, Engine};
+
+pub trait FnRegister {
+    fn register(self, engine: &mut Engine, name: &str);
+}
+
+impl<T: Any, U: Any> FnRegister for fn(&mut T)->U {
+    fn register(self, engine: &mut Engine, name: &str) {
+        let wrapped : Box<Fn(&mut Box<Any>)->Result<Box<Any>, EvalError>> = 
+            Box::new(
+                move |x: &mut Box<Any>| {
+                    let inside = (*x).downcast_mut() as Option<&mut T>;
+                    
+                    match inside {
+                        Some(b) => Ok(Box::new(self(b)) as Box<Any>),
+                        None => Err(EvalError::FunctionArgMismatch)
+                    }
+                }
+            );
+
+        let ent = engine.fns_arity_1.entry(name.to_string()).or_insert(Vec::new());
+        (*ent).push(wrapped);
+    }
+}
+
+impl<T: Any+Clone, U: Any> FnRegister for fn(T)->U {
+    fn register(self, engine: &mut Engine, name: &str) {        
+        let wrapped : Box<Fn(&mut Box<Any>)->Result<Box<Any>, EvalError>> = 
+            Box::new(
+                move |x: &mut Box<Any>| {
+                    let inside = (*x).downcast_mut() as Option<&mut T>;
+                    match inside {
+                        Some(b) => Ok(Box::new(self(b.clone())) as Box<Any>),
+                        None => Err(EvalError::FunctionArgMismatch)
+                    }
+                }
+            );
+
+        let ent = engine.fns_arity_1.entry(name.to_string()).or_insert(Vec::new());
+        (*ent).push(wrapped);
+    }
+}
+
+impl<T: Any> FnRegister for fn()->T {
+    fn register(self, engine: &mut Engine, name: &str) {
+        let wrapped : Box<Fn()->Result<Box<Any>, EvalError>> = 
+            Box::new(
+                move || { Ok(Box::new(self()) as Box<Any>) }
+            );
+
+        let ent = engine.fns_arity_0.entry(name.to_string()).or_insert(Vec::new());
+        (*ent).push(wrapped);
+    }
+}