test-case 9KAX

[hvr]

https://matrix.yaml.io/details/9KAX.html doesn't pass as of HsYAML-0.1.2.0 specifically because of

---
!!map
&a8 !!str key8: value7

which yaml2token decodes as

<stdin>:1:0: BeginDocument  | 
<stdin>:1:0: DirectivesEnd  |  ---
<stdin>:1:3: BeginNode      | 
<stdin>:1:3: BeginScalar    | 
<stdin>:1:3: EndScalar      | 
<stdin>:1:3: EndNode        | 
<stdin>:1:3: Break          |     \n

<stdin>:2:0: Unparsed       |  !!map
<stdin>:2:5: Unparsed       |       \n

<stdin>:3:0: Unparsed       | "&a8 !!str key8: value7"
<stdin>:3:22: Unparsed       |                        \n

<stdin>:4:0: EndDocument    | 

in other words, parsing chokes on the !!map token

TODO: review YAML 1.2 spec

[vijayphoenix]

I think the main source of the problem is production rule 200 in token.hs
It is a slightly improved version of the grammar production rule 200 in YAML 1.2 spec but still, some tweaks in this rule are required to fix this error.
For this example, it fails because we are not able to parse !!map as we are not able to detect s-l-comments in the look-ahead.
TODO: Review the definition of s_l_comments