WIP - new approach to autoindent

- Indent one row at a time.
- Consider only the innermost match.

zed/languages/rust/config.toml

@@ -1,4 +1,12 @@
 name = "Rust"
 path_suffixes = ["rs"]
 indent = 4
-indent_nodes = ["declaration_list", "block"]
+
+idents = [
+    { inside = "let_declaration" },
+    { inside = "field_declaration" },
+    { start = "where_clause", end = ["block", "field_declaration_list"] },
+    { after = "{", before = "}" },
+    { start = "(", end = ")" },
+    { start = "[", end = "]" },
+]

zed/languages/rust/indents.scm

@@ -1,7 +1,8 @@
-(where_clause) @indent
+(field_expression) @inside
+(let_declaration) @inside
 
-(field_expression) @indent
+((_ . "where" @after) _ @until)
 
-(_ "(" ")" @outdent) @indent
-(_ "[" "]" @outdent) @indent
-(_ "{" "}" @outdent) @indent
+(_ "{" @after "}" @until)
+(_ "[" @after "]" @until)
+(_ "(" @after ")" @until)