Clarify that the context root can be iterated

Since some implementations differ on whether the root of the context stack can be iterated over, this adds langauge to the "Sections" spec clarifying that it can. It also adds a test for this case.

Fixes mustache#87. I did not add the two additional tests for the "Interpolation" spec that I recommended in that issue, since there are tests that cover them now (not sure if these are new or if I just missed them before).

specs/sections.json

@@ -1,6 +1,6 @@
 {
   "__ATTN__": "Do not edit this file; changes belong in the appropriate YAML file.",
-  "overview": "Section tags and End Section tags are used in combination to wrap a section\nof the template for iteration\n\nThese tags' content MUST be a non-whitespace character sequence NOT\ncontaining the current closing delimiter; each Section tag MUST be followed\nby an End Section tag with the same content within the same section.\n\nThis tag's content names the data to replace the tag.  Name resolution is as\nfollows:\n  1) Split the name on periods; the first part is the name to resolve, any\n  remaining parts should be retained.\n  2) Walk the context stack from top to bottom, finding the first context\n  that is a) a hash containing the name as a key OR b) an object responding\n  to a method with the given name.\n  3) If the context is a hash, the data is the value associated with the\n  name.\n  4) If the context is an object and the method with the given name has an\n  arity of 1, the method SHOULD be called with a String containing the\n  unprocessed contents of the sections; the data is the value returned.\n  5) Otherwise, the data is the value returned by calling the method with\n  the given name.\n  6) If any name parts were retained in step 1, each should be resolved\n  against a context stack containing only the result from the former\n  resolution.  If any part fails resolution, the result should be considered\n  falsey, and should interpolate as the empty string.\nIf the data is not of a list type, it is coerced into a list as follows: if\nthe data is truthy (e.g. `!!data == true`), use a single-element list\ncontaining the data, otherwise use an empty list.\n\nFor each element in the data list, the element MUST be pushed onto the\ncontext stack, the section MUST be rendered, and the element MUST be popped\noff the context stack.\n\nSection and End Section tags SHOULD be treated as standalone when\nappropriate.\n",
+  "overview": "Section tags and End Section tags are used in combination to wrap a section\nof the template for iteration.\n\nThese tags' content MUST be a non-whitespace character sequence NOT\ncontaining the current closing delimiter; each Section tag MUST be followed\nby an End Section tag with the same content within the same section.\n\nThis tag's content names the data to replace the tag.  Name resolution is as\nfollows:\n  1) If the name is a single period (.), the data is the item currently\n  sitting atop the context stack. Skip the rest of these steps.\n  2) Split the name on periods; the first part is the name to resolve, any\n  remaining parts should be retained.\n  3) Walk the context stack from top to bottom, finding the first context\n  that is a) a hash containing the name as a key OR b) an object responding\n  to a method with the given name.\n  4) If the context is a hash, the data is the value associated with the\n  name.\n  5) If the context is an object and the method with the given name has an\n  arity of 1, the method SHOULD be called with a String containing the\n  unprocessed contents of the sections; the data is the value returned.\n  6) Otherwise, the data is the value returned by calling the method with\n  the given name.\n  7) If any name parts were retained in step 1, each should be resolved\n  against a context stack containing only the result from the former\n  resolution.  If any part fails resolution, the result should be considered\n  falsey, and should interpolate as the empty string.\n\nIf the data is not of a list type, it is coerced into a list as follows: if\nthe data is truthy (e.g. `!!data == true`), use a single-element list\ncontaining the data, otherwise use an empty list.\n\nFor each element in the data list, the element MUST be pushed onto the\ncontext stack, the section MUST be rendered, and the element MUST be popped\noff the context stack.\n\nSection and End Section tags SHOULD be treated as standalone when\nappropriate.\n",
   "tests": [
     {
       "name": "Truthy",
@@ -288,6 +288,20 @@
       "template": "\"{{#list}}({{&.}}){{/list}}\"",
       "expected": "\"(&)(\")(<)(>)\""
     },
+    {
+      "name": "Implicit Iterator - Root-level",
+      "desc": "Implicit iterators should work on root-level lists.",
+      "data": [
+        {
+          "value": "a"
+        },
+        {
+          "value": "b"
+        }
+      ],
+      "template": "\"{{#.}}({{value}}){{/.}}\"",
+      "expected": "\"(a)(b)\""
+    },
     {
       "name": "Dotted Names - Truthy",
       "desc": "Dotted names should be valid for Section tags.",

specs/sections.yml

@@ -1,29 +1,32 @@
 overview: |
   Section tags and End Section tags are used in combination to wrap a section
-  of the template for iteration
+  of the template for iteration.
 
   These tags' content MUST be a non-whitespace character sequence NOT
   containing the current closing delimiter; each Section tag MUST be followed
   by an End Section tag with the same content within the same section.
 
   This tag's content names the data to replace the tag.  Name resolution is as
   follows:
-    1) Split the name on periods; the first part is the name to resolve, any
+    1) If the name is a single period (.), the data is the item currently
+    sitting atop the context stack. Skip the rest of these steps.
+    2) Split the name on periods; the first part is the name to resolve, any
     remaining parts should be retained.
-    2) Walk the context stack from top to bottom, finding the first context
+    3) Walk the context stack from top to bottom, finding the first context
     that is a) a hash containing the name as a key OR b) an object responding
     to a method with the given name.
-    3) If the context is a hash, the data is the value associated with the
+    4) If the context is a hash, the data is the value associated with the
     name.
-    4) If the context is an object and the method with the given name has an
+    5) If the context is an object and the method with the given name has an
     arity of 1, the method SHOULD be called with a String containing the
     unprocessed contents of the sections; the data is the value returned.
-    5) Otherwise, the data is the value returned by calling the method with
+    6) Otherwise, the data is the value returned by calling the method with
     the given name.
-    6) If any name parts were retained in step 1, each should be resolved
+    7) If any name parts were retained in step 1, each should be resolved
     against a context stack containing only the result from the former
     resolution.  If any part fails resolution, the result should be considered
     falsey, and should interpolate as the empty string.
+
   If the data is not of a list type, it is coerced into a list as follows: if
   the data is truthy (e.g. `!!data == true`), use a single-element list
   containing the data, otherwise use an empty list.
@@ -227,6 +230,12 @@ tests:
     template: '"{{#list}}({{&.}}){{/list}}"'
     expected: '"(&)(")(<)(>)"'
 
+  - name: Implicit Iterator - Root-level
+    desc: Implicit iterators should work on root-level lists.
+    data: [ { value: 'a' }, { value: 'b' } ]
+    template: '"{{#.}}({{value}}){{/.}}"'
+    expected: '"(a)(b)"'
+
   # Dotted Names
 
   - name: Dotted Names - Truthy