Parse self-references and add a test for sections.

src/parser/parser.rs

@@ -58,6 +58,9 @@ pub struct Comment<'a> {
     value: &'a str,
 }
 
+/// A series of keys separated by '.' to reference a variable in the context
+///
+/// Special case: If the path is just "." then keys will be an empty vec
 #[derive(Clone, Debug, PartialEq)]
 pub struct Path<'a> {
     pub keys: Vec<&'a str>,
@@ -197,7 +200,10 @@ fn key(i: &str) -> IResult<&str, &str> {
 
 /// A series of keys separated by '.' to reference a variable in the context
 fn path(i: &str) -> IResult<&str, Path> {
-    map(separated_list1(tag("."), key), |body| Path { keys: body })(i)
+    alt((
+        map(separated_list1(tag("."), key), |body| Path { keys: body }),
+        value(Path { keys: Vec::new() }, tag(".")),
+    ))(i)
 }
 
 /// Either a literal or a path to a value