From 2dbbc7b1284ffb9f9f8a25cf4436f4880b647b3f Mon Sep 17 00:00:00 2001
From: Jeff <dev@jeffa.io>
Date: Fri, 12 Jul 2024 16:16:28 -0400
Subject: [PATCH] Make errors nice

---
 dust-lang/src/abstract_tree/value_node.rs | 30 ++++-------------------
 dust-lang/src/error.rs                    |  1 +
 dust-lang/src/lib.rs                      | 14 ++++++++++-
 3 files changed, 19 insertions(+), 26 deletions(-)

diff --git a/dust-lang/src/abstract_tree/value_node.rs b/dust-lang/src/abstract_tree/value_node.rs
index 526161b..f818067 100644
--- a/dust-lang/src/abstract_tree/value_node.rs
+++ b/dust-lang/src/abstract_tree/value_node.rs
@@ -122,34 +122,14 @@ impl AbstractNode for ValueNode {
                         return Err(ValidationError::WrongTypeArgumentsCount {
                             expected: parameters.len(),
                             actual: arguments.len(),
+                            position: arguments.last().unwrap().position(),
                         });
                     }
 
-                    let mut arguments = arguments.iter();
-                    let mut found = false;
-
-                    for (identifier, content) in variants {
-                        if identifier == variant.node {
-                            found = true;
-                        }
-
-                        if let Some(content) = content {
-                            for expected_type in &content {
-                                if let Type::Generic {
-                                    concrete_type: None,
-                                    ..
-                                } = expected_type
-                                {
-                                    arguments.next().ok_or_else(|| {
-                                        ValidationError::WrongTypeArgumentsCount {
-                                            expected: content.len(),
-                                            actual: arguments.len(),
-                                        }
-                                    })?;
-                                }
-                            }
-                        }
-                    }
+                    let found = variants
+                        .into_iter()
+                        .find(|(identifier, _)| identifier == &variant.node)
+                        .is_some();
 
                     if !found {
                         return Err(ValidationError::EnumVariantNotFound {
diff --git a/dust-lang/src/error.rs b/dust-lang/src/error.rs
index b47b0b1..29002ca 100644
--- a/dust-lang/src/error.rs
+++ b/dust-lang/src/error.rs
@@ -184,6 +184,7 @@ pub enum ValidationError {
     WrongTypeArgumentsCount {
         expected: usize,
         actual: usize,
+        position: SourcePosition,
     },
 }
 
diff --git a/dust-lang/src/lib.rs b/dust-lang/src/lib.rs
index 12f8de2..19f7a43 100644
--- a/dust-lang/src/lib.rs
+++ b/dust-lang/src/lib.rs
@@ -445,7 +445,19 @@ impl InterpreterError {
                         .add_label(Label::new((self.source_id.clone(), 0..0)).with_message(reason)),
                     ValidationError::CannotUsePath(_) => todo!(),
                     ValidationError::Uninitialized => todo!(),
-                    ValidationError::WrongTypeArgumentsCount { expected, actual } => todo!(),
+                    ValidationError::WrongTypeArgumentsCount {
+                        expected,
+                        actual,
+                        position,
+                    } => builder.add_label(
+                        Label::new((self.source_id.clone(), position.0..position.1)).with_message(
+                            format!(
+                                "Expected {} type arguments but got {}.",
+                                expected.fg(type_color),
+                                actual.fg(type_color)
+                            ),
+                        ),
+                    ),
                 }
             }