Add output function

src/context.rs

@@ -6,6 +6,7 @@ use std::{
 use crate::{
     abstract_tree::{Identifier, Type},
     error::RwLockPoisonError,
+    value::BuiltInFunction,
     Value,
 };
 
@@ -36,23 +37,42 @@ impl Context {
         &self,
         identifier: &Identifier,
     ) -> Result<Option<ValueData>, RwLockPoisonError> {
-        Ok(self.inner.read()?.get(identifier).cloned())
+        if let Some(value_data) = self.inner.read()?.get(identifier) {
+            return Ok(Some(value_data.clone()));
+        }
+
+        let value_data = match identifier.as_str() {
+            "output" => ValueData::Value(BuiltInFunction::output()),
+            _ => return Ok(None),
+        };
+
+        Ok(Some(value_data))
     }
 
     pub fn get_type(&self, identifier: &Identifier) -> Result<Option<Type>, RwLockPoisonError> {
         if let Some(ValueData::Type(r#type)) = self.inner.read()?.get(identifier) {
-            Ok(Some(r#type.clone()))
+            return Ok(Some(r#type.clone()));
-        } else {
-            Ok(None)
         }
+
+        let r#type = match identifier.as_str() {
+            "output" => BuiltInFunction::Output.r#type(),
+            _ => return Ok(None),
+        };
+
+        Ok(Some(r#type))
     }
 
     pub fn get_value(&self, identifier: &Identifier) -> Result<Option<Value>, RwLockPoisonError> {
         if let Some(ValueData::Value(value)) = self.inner.read()?.get(identifier) {
-            Ok(Some(value.clone()))
+            return Ok(Some(value.clone()));
-        } else {
-            Ok(None)
         }
+
+        let value = match identifier.as_str() {
+            "output" => BuiltInFunction::output(),
+            _ => return Ok(None),
+        };
+
+        Ok(Some(value))
     }
 
     pub fn set_type(&self, identifier: Identifier, r#type: Type) -> Result<(), RwLockPoisonError> {

src/error.rs

@@ -56,7 +56,7 @@ impl Error {
             Error::Runtime(_) => todo!(),
             Error::Validation { error, span } => {
                 let mut report = Report::build(
-                    ReportKind::Custom("Lexing Error", Color::White),
+                    ReportKind::Custom("Validation Error", Color::White),
                     (),
                     span.start,
                 );

src/value.rs

@@ -87,6 +87,10 @@ impl Value {
         ))))
     }
 
+    pub fn built_in_function(function: BuiltInFunction) -> Self {
+        Value(Arc::new(ValueInner::Function(Function::BuiltIn(function))))
+    }
+
     pub fn r#type(&self) -> Type {
         match self.0.as_ref() {
             ValueInner::Boolean(_) => Type::Boolean,
@@ -343,22 +347,30 @@ pub struct ParsedFunction {
 
 #[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
 pub enum BuiltInFunction {
-    Output(Value),
+    Output,
 }
 
 impl BuiltInFunction {
-    fn r#type(&self, context: &Context) -> Type {
+    pub fn output() -> Value {
+        static OUTPUT: OnceLock<Value> = OnceLock::new();
+
+        OUTPUT
+            .get_or_init(|| Value::built_in_function(BuiltInFunction::Output))
+            .clone()
+    }
+
+    pub fn r#type(&self) -> Type {
         match self {
-            BuiltInFunction::Output(_) => Type::Function {
+            BuiltInFunction::Output => Type::Function {
                 parameter_types: vec![Type::Any],
                 return_type: Box::new(Type::None),
             },
         }
     }
 
-    fn call(self, context: &Context) -> Result<Action, RuntimeError> {
+    pub fn call(self, value: Value, _context: &Context) -> Result<Action, RuntimeError> {
         match self {
-            BuiltInFunction::Output(value) => {
+            BuiltInFunction::Output => {
                 println!("{value}");
 
                 Ok(Action::None)
@@ -370,7 +382,7 @@ impl BuiltInFunction {
 impl Display for BuiltInFunction {
     fn fmt(&self, f: &mut Formatter) -> fmt::Result {
         match self {
-            BuiltInFunction::Output(_) => write!(f, "(to_output : any) : none rust_magic();"),
+            BuiltInFunction::Output => write!(f, "(to_output : any) : none rust_magic();"),
         }
     }
 }