Parse self-references and add a test for sections.

js/test_cases/dot_reference/input1.json

@@ -0,0 +1 @@
+{"names": ["Alice", "Bob", "Chris"]}

js/test_cases/dot_reference/main.dust

@@ -0,0 +1,3 @@
+{#names}
+Hello {.}!
+{/names}

js/test_cases/sections/input1.json

@@ -0,0 +1 @@
+{"things": ["Alice", "Bob", "Chris"]}

js/test_cases/sections/input10.json

@@ -0,0 +1 @@
+{"things": {}}

js/test_cases/sections/input2.json

@@ -0,0 +1 @@
+{"things": {"name": "Alice", "keyboard": "K-Type"}}

js/test_cases/sections/input3.json

@@ -0,0 +1 @@
+{"there_are_no_things": 4}

js/test_cases/sections/input4.json

@@ -0,0 +1 @@
+{"things": "just a string"}

js/test_cases/sections/input5.json

@@ -0,0 +1 @@
+{"things": false}

js/test_cases/sections/input6.json

@@ -0,0 +1 @@
+{"things": null}

js/test_cases/sections/input7.json

@@ -0,0 +1 @@
+{"things": 0}

js/test_cases/sections/input8.json

@@ -0,0 +1 @@
+{"things": ""}

js/test_cases/sections/input9.json

@@ -0,0 +1 @@
+{"things": []}

js/test_cases/sections/main.dust

@@ -0,0 +1,5 @@
+{#things}
+Thing: {.}
+{:else}
+No things
+{/things}

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