feat: function (WIP)

src/ty/internal/func.rs

@@ -1,5 +1,6 @@
 use ecow::EcoString;
 
+use crate::ty::internal::Value;
 use crate::bytecode::{OpCodes, ThunkIdx};
 
 #[derive(Debug, Clone)]
@@ -18,6 +19,12 @@ pub struct Func {
     pub opcodes: OpCodes
 }
 
+impl Func {
+    pub fn call(self, _arg: Value) -> Value {
+        todo!()
+    }
+}
+
 impl PartialEq for Func {
     fn eq(&self, _: &Self) -> bool {
         false

src/ty/internal/mod.rs

@@ -43,10 +43,31 @@ pub enum Value {
 
 use Value::Const as VmConst;
 impl Value {
-    pub fn call(self, args: Vec<Value>) -> Value {
+    pub fn callable(&self) -> bool {
         match self {
-            Value::PrimOp(func) => func.call(args),
-            Value::PartialPrimOp(func) => func.call(args),
+            Value::PrimOp(_) | Value::PartialPrimOp(_) | Value::Const(Const::Func(_)) => true,
+            Value::AttrSet(_) => todo!(),
+            _ => false,
+        }
+    }
+
+    pub fn call(self, args: Vec<Value>) -> Value {
+        use Value as V;
+        match self {
+            V::PrimOp(func) => func.call(args),
+            V::PartialPrimOp(func) => func.call(args),
+            mut func @ Value::Const(Const::Func(_)) => {
+                let mut iter = args.into_iter();
+                while let Some(arg) = iter.next() {
+                    func = match func {
+                        V::PrimOp(func) => return func.call([arg].into_iter().chain(iter).collect()),
+                        V::PartialPrimOp(func) => return func.call([arg].into_iter().chain(iter).collect()),
+                        V::Const(Const::Func(func)) => func.call(arg),
+                        _ => todo!()
+                    }
+                }
+                func
+            }
             _ => todo!(),
         }
     }