Refactor function signatures to use slices

src/ast/types.rs

@@ -204,9 +204,12 @@ pub enum Purity {
     Pure,
 }
 
+pub type NativeFn = dyn Fn(&[Value]) -> Value;
+pub type PipeFn = dyn FnMut(&[Value]) -> Value;
+
 /// A native host function with metadata.
 pub struct NativeFunction {
-    pub func: Rc<dyn Fn(Vec<Value>) -> Value>,
+    pub func: Rc<NativeFn>,
     pub purity: Purity,
 }
 
@@ -503,7 +506,7 @@ impl Value {
         Value::Record(layout, Rc::new(values))
     }
 
-    pub fn make_function(purity: Purity, func: impl Fn(Vec<Value>) -> Value + 'static) -> Self {
+    pub fn make_function(purity: Purity, func: impl Fn(&[Value]) -> Value + 'static) -> Self {
         Value::Function(Rc::new(NativeFunction {
             func: Rc::new(func),
             purity,