Begin fixing map property parsing

dust-lang/src/parser.rs

@@ -596,11 +596,17 @@ impl<'src> Parser<'src> {
 
     fn parse_infix(&mut self, left: Node<Statement>) -> Result<Node<Statement>, ParseError> {
         let left_start = left.position.0;
+        let operator_precedence = self.current.0.precedence()
+            - if self.current.0.is_right_associative() {
+                1
+            } else {
+                0
+            };
 
         if let Token::Dot = &self.current.0 {
             self.next_token()?;
 
-            let right = self.parse_statement(0)?;
+            let right = self.parse_statement(operator_precedence)?;
             let right_end = right.position.1;
 
             if let Statement::BuiltInFunctionCall {
@@ -679,12 +685,6 @@ impl<'src> Parser<'src> {
                 });
             }
         };
-        let operator_precedence = self.current.0.precedence()
-            - if self.current.0.is_right_associative() {
-                1
-            } else {
-                0
-            };
 
         self.next_token()?;
 
@@ -845,6 +845,59 @@ mod tests {
 
     use super::*;
 
+    #[test]
+    fn map_property_nested() {
+        let input = "{ x = { y = 42 } }.x.y";
+
+        assert_eq!(
+            parse(input),
+            Ok(AbstractSyntaxTree {
+                nodes: [Node {
+                    inner: Statement::PropertyAccess(
+                        Box::new(Node {
+                            inner: Statement::Map(vec![(
+                                Node {
+                                    inner: Statement::Identifier(Identifier::new("x")),
+                                    position: (2, 3)
+                                },
+                                Node {
+                                    inner: Statement::Map(vec![(
+                                        Node {
+                                            inner: Statement::Identifier(Identifier::new("y")),
+                                            position: (8, 9)
+                                        },
+                                        Node {
+                                            inner: Statement::Constant(Value::integer(42)),
+                                            position: (12, 14)
+                                        }
+                                    )]),
+                                    position: (6, 16)
+                                }
+                            )]),
+                            position: (0, 18)
+                        }),
+                        Box::new(Node {
+                            inner: Statement::PropertyAccess(
+                                Box::new(Node {
+                                    inner: Statement::Identifier(Identifier::new("x")),
+                                    position: (19, 20)
+                                }),
+                                Box::new(Node {
+                                    inner: Statement::Identifier(Identifier::new("y")),
+
+                                    position: (21, 22)
+                                })
+                            ),
+                            position: (19, 22)
+                        })
+                    ),
+                    position: (0, 22)
+                }]
+                .into()
+            })
+        )
+    }
+
     #[test]
     fn range() {
         let input = "0..42";

dust-lang/src/value.rs

@@ -153,6 +153,14 @@ impl Value {
         }
     }
 
+    pub fn as_string(&self) -> Option<&String> {
+        if let ValueInner::String(string) = self.inner().as_ref() {
+            Some(string)
+        } else {
+            None
+        }
+    }
+
     pub fn add(&self, other: &Value) -> Result<Value, ValueError> {
         match (self.inner().as_ref(), other.inner().as_ref()) {
             (ValueInner::Float(left), ValueInner::Float(right)) => Ok(Value::float(left + right)),

dust-lang/src/vm.rs

@@ -495,12 +495,22 @@ impl Vm {
                     }
                 }
 
-                if let (Some(map), Statement::Identifier(identifier)) =
-                    (left_value.as_map(), &right.inner)
-                {
-                    let value = map.get(identifier).cloned();
+                if let Some(map) = left_value.as_map() {
+                    if let Statement::Identifier(identifier) = right.inner {
+                        let value = map.get(&identifier).cloned();
 
-                    return Ok(value);
+                        return Ok(value);
+                    }
+
+                    if let Some(value) = self.run_statement(*right)? {
+                        if let Some(string) = value.as_string() {
+                            let identifier = Identifier::new(string);
+
+                            let value = map.get(&identifier).cloned();
+
+                            return Ok(value);
+                        }
+                    }
                 }
 
                 Err(VmError::ExpectedIdentifierIntegerOrRange {
@@ -701,6 +711,27 @@ impl Display for VmError {
 mod tests {
     use super::*;
 
+    #[test]
+    fn map_property() {
+        let input = "{ x = 42 }.x";
+
+        assert_eq!(run(input), Ok(Some(Value::integer(42))));
+    }
+
+    #[test]
+    fn map_property_nested() {
+        let input = "{ x = { y = 42 } }.x.y";
+
+        assert_eq!(run(input), Ok(Some(Value::integer(42))));
+    }
+
+    #[test]
+    fn map_property_access_expression() {
+        let input = "{ foobar = 42 }.('foo' + 'bar')";
+
+        assert_eq!(run(input), Ok(Some(Value::integer(42))));
+    }
+
     #[test]
     fn list_index_range() {
         let input = "[1, 2, 3, 4, 5].1..3";