Improve index parsing

src/abstract_tree/function_expression.rs

@@ -19,7 +19,12 @@ impl AbstractTree for FunctionExpression {
     fn from_syntax_node(source: &str, node: Node, context: &Map) -> Result<Self> {
         Error::expect_syntax_node(source, "function_expression", node)?;
 
-        let child = node.child(0).unwrap();
+        let first_child = node.child(0).unwrap();
+        let child = if first_child.is_named() {
+            first_child
+        } else {
+            node.child(1).unwrap()
+        };
 
         let function_expression = match child.kind() {
             "identifier" => FunctionExpression::Identifier(Identifier::from_syntax_node(

src/abstract_tree/index.rs

@@ -94,7 +94,7 @@ impl AbstractTree for Index {
             Type::List(item_type) => Ok(*item_type.clone()),
             Type::Map => Ok(Type::Any),
             Type::None => Ok(Type::None),
-            _ => todo!(),
+            r#type => Ok(r#type),
         }
     }
 }

src/built_in_functions/std.rs

@@ -15,7 +15,7 @@ impl BuiltInFunction for Std {
         Error::expect_argument_amount(self, 0, arguments.len())?;
 
         let std_context = STD.get_or_init(|| {
-            let std_source = "say_hi = () <none> { output(hi) }";
+            let std_source = "say_hi = () <none> { output('hi') }";
             let std_context = Map::new();
 
             interpret_with_context(std_source, std_context.clone()).unwrap();

src/lib.rs

@@ -3,7 +3,6 @@
 //!
 //! Using this library is simple and straightforward, see the [inferface] module for instructions on
 //! interpreting Dust code. Most of the language's features are implemented in the [tools] module.
-
 pub use crate::{
     abstract_tree::*,
     built_in_functions::{BuiltInFunction, BUILT_IN_FUNCTIONS},

tests/interpret.rs

@@ -338,17 +338,29 @@ mod index {
     }
 
     #[test]
-    fn complex_index() {
-        let test = interpret(
+    fn index_function_calls() {
+        assert_eq!(
+            interpret(
                 "
                 x = [1 2 3]
                 y = () <int> { 2 }
                 x:y()
                 ",
-        )
-        .unwrap();
+            ),
+            Ok(Value::Integer(3))
+        );
 
-        assert_eq!(Value::Integer(3), test);
+        assert_eq!(
+            interpret(
+                "
+                x = {
+                    y = () <int> { 2 }
+                }
+                (x:y)()
+                ",
+            ),
+            Ok(Value::Integer(2))
+        );
     }
 }
 

tree-sitter-dust/grammar.js

@@ -200,7 +200,7 @@ module.exports = grammar({
 
     index: $ =>
       prec.left(
-        2,
+        1,
         seq(
           $.expression,
           ':',
@@ -377,6 +377,16 @@ module.exports = grammar({
       ),
 
     function_expression: $ =>
+      choice(
+        $._function_expression_kind,
+        seq(
+          '(',
+          $._function_expression_kind,
+          ')',
+        ),
+      ),
+
+    _function_expression_kind: $ =>
       prec(
         1,
         choice(
@@ -387,7 +397,6 @@ module.exports = grammar({
           $.yield,
         ),
       ),
-
     function_call: $ =>
       prec.right(
         seq(

tree-sitter-dust/src/grammar.json

@@ -599,7 +599,7 @@
     },
     "index": {
       "type": "PREC_LEFT",
-      "value": 2,
+      "value": 1,
       "content": {
         "type": "SEQ",
         "members": [
@@ -1231,6 +1231,32 @@
       ]
     },
     "function_expression": {
+      "type": "CHOICE",
+      "members": [
+        {
+          "type": "SYMBOL",
+          "name": "_function_expression_kind"
+        },
+        {
+          "type": "SEQ",
+          "members": [
+            {
+              "type": "STRING",
+              "value": "("
+            },
+            {
+              "type": "SYMBOL",
+              "name": "_function_expression_kind"
+            },
+            {
+              "type": "STRING",
+              "value": ")"
+            }
+          ]
+        }
+      ]
+    },
+    "_function_expression_kind": {
       "type": "PREC",
       "value": 1,
       "content": {