Add indexing to build.rs.

src/ast/build.rs

@@ -1173,26 +1173,45 @@ fn build_primary_expression(file_id: usize, primary_expression_pair: Pair<Rule>)
 fn build_object_access(
     file_id: usize,
     receiver: Expression,
-    navigations_pair: Pair<Rule>,
+    object_access_pair: Pair<Rule>,
 ) -> ObjectAccess {
     ObjectAccess {
         receiver: Box::new(receiver),
         navigations: ObjectNavigations(
-            navigations_pair
+            object_access_pair
                 .into_inner()
-                .map(|identifier_pair| {
-                    ObjectNavigation::Identifier(Box::new(expect_and_use(
-                        file_id,
-                        identifier_pair,
-                        Rule::Identifier,
-                        build_identifier,
-                    )))
-                })
+                .map(
+                    |property_or_index_pair| match property_or_index_pair.as_rule() {
+                        Rule::ObjectProperty => {
+                            build_object_property(file_id, property_or_index_pair)
+                        }
+                        Rule::ObjectIndex => build_object_index(file_id, property_or_index_pair),
+                        _ => unreachable!(),
+                    },
+                )
                 .collect(),
         ),
     }
 }
 
+fn build_object_property(file_id: usize, inner_pair: Pair<Rule>) -> ObjectNavigation {
+    ObjectNavigation::Identifier(Box::new(expect_and_use(
+        file_id,
+        inner_pair.into_inner().next().unwrap(),
+        Rule::Identifier,
+        build_identifier,
+    )))
+}
+
+fn build_object_index(file_id: usize, inner_pair: Pair<Rule>) -> ObjectNavigation {
+    ObjectNavigation::Index(Box::new(expect_and_use(
+        file_id,
+        inner_pair.into_inner().next().unwrap(),
+        Rule::Expression,
+        build_expression,
+    )))
+}
+
 fn build_closure(file_id: usize, closure_pair: Pair<Rule>) -> Closure {
     todo!()
 }
@@ -1242,3 +1261,37 @@ fn build_double_quote_string(file_id: usize, pair: Pair<Rule>) -> Literal {
 fn build_backtick_string(file_id: usize, pair: Pair<Rule>) -> Literal {
     todo!()
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::parser::DeimosParser;
+    use indoc::indoc;
+
+    fn assert_builds(src: &str) {
+        let parse_result = DeimosParser::parse(Rule::CompilationUnit, src);
+        if let Err(e) = parse_result {
+            panic!("Parsing failed.\n{}", e)
+        } else {
+            build_ast(0, parse_result.unwrap().next().unwrap());
+        }
+    }
+
+    #[test]
+    fn index_object() {
+        assert_builds(indoc! {"
+        fn main() {
+            let x = foo[a];
+        }
+        "})
+    }
+
+    #[test]
+    fn object_index_and_call() {
+        assert_builds(indoc! {"\
+        fn main() {
+            a[b]().c()
+        }
+        "})
+    }
+}