Add type definitions as a first-class value

src/abstract_tree/value_node.rs

@@ -4,7 +4,8 @@ use serde::{Deserialize, Serialize};
 
 use crate::{
     AbstractTree, BuiltInValue, Error, Expression, Format, Function, FunctionNode, Identifier,
-    List, Map, Result, Statement, Structure, SyntaxNode, Type, TypeSpecification, Value,
+    List, Map, Result, Statement, Structure, SyntaxNode, Type, TypeDefintion, TypeSpecification,
+    Value,
 };
 
 #[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
@@ -18,7 +19,7 @@ pub enum ValueNode {
     Option(Option<Box<Expression>>),
     Map(BTreeMap<String, (Statement, Option<Type>)>),
     BuiltInValue(BuiltInValue),
-    Structure(BTreeMap<String, (Option<Statement>, Type)>),
+    StructureDefinition(BTreeMap<String, (Option<Statement>, Type)>),
 }
 
 impl AbstractTree for ValueNode {
@@ -159,7 +160,7 @@ impl AbstractTree for ValueNode {
                     }
                 }
 
-                ValueNode::Structure(btree_map)
+                ValueNode::StructureDefinition(btree_map)
             }
             _ => {
                 return Err(Error::UnexpectedSyntaxNode {
@@ -229,7 +230,7 @@ impl AbstractTree for ValueNode {
                 Value::Map(map)
             }
             ValueNode::BuiltInValue(built_in_value) => built_in_value.run(source, context)?,
-            ValueNode::Structure(node_map) => {
+            ValueNode::StructureDefinition(node_map) => {
                 let mut value_map = BTreeMap::new();
 
                 for (key, (statement_option, r#type)) in node_map {
@@ -242,7 +243,7 @@ impl AbstractTree for ValueNode {
                     value_map.insert(key.to_string(), (value_option, r#type.clone()));
                 }
 
-                Value::Structure(Structure::new(value_map))
+                Value::TypeDefinition(TypeDefintion::Structure(Structure::new(value_map)))
             }
         };
 
@@ -286,7 +287,7 @@ impl AbstractTree for ValueNode {
             }
             ValueNode::Map(_) => Type::Map(None),
             ValueNode::BuiltInValue(built_in_value) => built_in_value.expected_type(context)?,
-            ValueNode::Structure(node_map) => {
+            ValueNode::StructureDefinition(node_map) => {
                 let mut value_map = BTreeMap::new();
 
                 for (key, (_statement_option, r#type)) in node_map {
@@ -356,7 +357,7 @@ impl Format for ValueNode {
                 output.push('}');
             }
             ValueNode::BuiltInValue(built_in_value) => built_in_value.format(output, indent_level),
-            ValueNode::Structure(nodes) => {
+            ValueNode::StructureDefinition(nodes) => {
                 output.push('{');
 
                 for (key, (value_option, r#type)) in nodes {

src/lib.rs

@@ -8,7 +8,10 @@ pub use crate::{
     built_in_functions::BuiltInFunction,
     error::*,
     interpret::*,
-    value::{function::Function, list::List, map::Map, structure::Structure, Value},
+    value::{
+        function::Function, list::List, map::Map, structure::Structure,
+        type_definition::TypeDefintion, Value,
+    },
 };
 
 pub use tree_sitter::Node as SyntaxNode;

src/value/mod.rs

@@ -1,7 +1,7 @@
 //! Types that represent runtime values.
 use crate::{
     error::{Error, Result},
-    Function, Identifier, List, Map, Structure, Type, TypeSpecification,
+    Function, Identifier, List, Map, Type, TypeDefintion, TypeSpecification,
 };
 
 use serde::{
@@ -22,6 +22,7 @@ pub mod function;
 pub mod list;
 pub mod map;
 pub mod structure;
+pub mod type_definition;
 
 /// Dust value representation.
 ///
@@ -38,7 +39,7 @@ pub enum Value {
     Integer(i64),
     Boolean(bool),
     Option(Option<Box<Value>>),
-    Structure(Structure),
+    TypeDefinition(TypeDefintion),
 }
 
 impl Default for Value {
@@ -99,7 +100,7 @@ impl Value {
                     Type::None
                 }
             }
-            Value::Structure(_) => todo!(),
+            Value::TypeDefinition(_) => todo!(),
         };
 
         r#type
@@ -432,7 +433,7 @@ impl PartialEq for Value {
             (Value::Map(left), Value::Map(right)) => left == right,
             (Value::Function(left), Value::Function(right)) => left == right,
             (Value::Option(left), Value::Option(right)) => left == right,
-            (Value::Structure(left), Value::Structure(right)) => left == right,
+            (Value::TypeDefinition(left), Value::TypeDefinition(right)) => left == right,
             _ => false,
         }
     }
@@ -469,8 +470,8 @@ impl Ord for Value {
             (Value::Map(_), _) => Ordering::Greater,
             (Value::Function(left), Value::Function(right)) => left.cmp(right),
             (Value::Function(_), _) => Ordering::Greater,
-            (Value::Structure(left), Value::Structure(right)) => left.cmp(right),
+            (Value::TypeDefinition(left), Value::TypeDefinition(right)) => left.cmp(right),
-            (Value::Structure(_), _) => Ordering::Greater,
+            (Value::TypeDefinition(_), _) => Ordering::Greater,
             (Value::Option(left), Value::Option(right)) => left.cmp(right),
             (Value::Option(_), _) => Ordering::Less,
         }
@@ -500,7 +501,7 @@ impl Serialize for Value {
             Value::Option(inner) => inner.serialize(serializer),
             Value::Map(inner) => inner.serialize(serializer),
             Value::Function(inner) => inner.serialize(serializer),
-            Value::Structure(inner) => inner.serialize(serializer),
+            Value::TypeDefinition(inner) => inner.serialize(serializer),
         }
     }
 }
@@ -522,7 +523,7 @@ impl Display for Value {
             Value::List(list) => write!(f, "{list}"),
             Value::Map(map) => write!(f, "{map}"),
             Value::Function(function) => write!(f, "{function}"),
-            Value::Structure(structure) => write!(f, "{structure}"),
+            Value::TypeDefinition(structure) => write!(f, "{structure}"),
         }
     }
 }

src/value/type_definition.rs

@@ -0,0 +1,16 @@
+use std::fmt::{self, Display, Formatter};
+
+use serde::{Deserialize, Serialize};
+
+use crate::Structure;
+
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
+pub enum TypeDefintion {
+    Structure(Structure),
+}
+
+impl Display for TypeDefintion {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        write!(f, "{self}")
+    }
+}

tests/structure.rs

@@ -10,5 +10,9 @@ fn simple_structure() {
 
     btree_map.insert("x".to_string(), (Some(Value::Integer(0)), Type::Integer));
 
-    assert_eq!(Ok(Value::Structure(Structure::new(btree_map))), result);
+    let expected = Ok(Value::TypeDefinition(TypeDefintion::Structure(
+        Structure::new(btree_map),
+    )));
+
+    assert_eq!(expected, result);
 }

tree-sitter-dust/corpus/structure.txt

@@ -13,13 +13,14 @@ struct {
   (statement
     (expression
       (value
+        (type_definition
           (structure
             (identifier)
             (type_specification
               (type))
             (identifier)
             (type_specification
-            (type)))))))
+              (type))))))))
 
 ================================================================================
 Complex Structure
@@ -44,6 +45,7 @@ Foo = struct {
       (statement
         (expression
           (value
+            (type_definition
               (structure
                 (identifier)
                 (type_specification
@@ -67,4 +69,4 @@ Foo = struct {
                       (statement
                         (expression
                           (value
-                          (integer))))))))))))))
+                            (integer)))))))))))))))

tree-sitter-dust/grammar.js

@@ -85,6 +85,11 @@ module.exports = grammar({
         $.map,
         $.option,
         $.built_in_value,
+        $.type_definition,
+      ),
+
+    type_definition: $ =>
+      choice(
         $.structure,
       ),
 

tree-sitter-dust/src/grammar.json

@@ -249,6 +249,15 @@
           "type": "SYMBOL",
           "name": "built_in_value"
         },
+        {
+          "type": "SYMBOL",
+          "name": "type_definition"
+        }
+      ]
+    },
+    "type_definition": {
+      "type": "CHOICE",
+      "members": [
         {
           "type": "SYMBOL",
           "name": "structure"

tree-sitter-dust/src/node-types.json

@@ -602,6 +602,21 @@
       ]
     }
   },
+  {
+    "type": "type_definition",
+    "named": true,
+    "fields": {},
+    "children": {
+      "multiple": false,
+      "required": true,
+      "types": [
+        {
+          "type": "structure",
+          "named": true
+        }
+      ]
+    }
+  },
   {
     "type": "type_specification",
     "named": true,
@@ -662,7 +677,7 @@
           "named": true
         },
         {
-          "type": "structure",
+          "type": "type_definition",
           "named": true
         }
       ]