[BUG] plyara parses invalid rule

[schrodyn]

I intentionally added an extra and to the condition in the following rule:

rule HackTool_MSIL_Rubeus_1_Wibble
{
    meta:
        description = "The TypeLibGUID present in a .NET binary maps directly to the ProjectGuid found in the '.csproj' file of a .NET project. This rule looks for .NET PE files that contain the ProjectGuid found in the public Rubeus project."
        md5 = "66e0681a500c726ed52e5ea9423d2654"
        reference = "https://www.fireeye.com/blog/products-and-services/2020/12/fireeye-shares-details-of-recent-cyber-attack-actions-to-protect-community.html"
        author = "FireEye"
    strings:
        $typelibguid = "658C8B7F-3664-4A95-9572-A3E5871DFC06" ascii nocase wide
    condition:
        uint16(0) == 0x5A4D and $typelibguid and
}

Yara won't accept this rule as it's invalid:

$ yara /tmp/test.yar ~/Downloads/MALWARE
error: rule "HackTool_MSIL_Rubeus_1_Wibble" in /tmp/test.yar(12): syntax error, unexpected '}'

But plyara parses the rule without any errors:

$ plyara /tmp/test.yar
[
    {
        "condition_terms": [
            "uint16",
            "(",
            "0",
            ")",
            "==",
            "0x5A4D",
            "and",
            "$typelibguid",
            "and"
        ],
        "metadata": [
            {
                "description": "The TypeLibGUID present in a .NET binary maps directly to the ProjectGuid found in the '.csproj' file of a .NET project. This rule looks for .NET PE files that contain the ProjectGuid found in the public Rubeus project."
            },
            {
                "md5": "66e0681a500c726ed52e5ea9423d2654"
            },
            {
                "reference": "https://www.fireeye.com/blog/products-and-services/2020/12/fireeye-shares-details-of-recent-cyber-attack-actions-to-protect-community.html"
            },
            {
                "author": "FireEye"
            }
        ],
        "raw_condition": "condition:\n        uint16(0) == 0x5A4D and $typelibguid and\n",
        "raw_meta": "meta:\n        description = \"The TypeLibGUID present in a .NET binary maps directly to the ProjectGuid found in the '.csproj' file of a .NET project. This rule looks for .NET PE files that contain the ProjectGuid found in the public Rubeus project.\"\n        md5 = \"66e0681a500c726ed52e5ea9423d2654\"\n        reference = \"https://www.fireeye.com/blog/products-and-services/2020/12/fireeye-shares-details-of-recent-cyber-attack-actions-to-protect-community.html\"\n        author = \"FireEye\"\n    ",
        "raw_strings": "strings:\n        $typelibguid = \"658C8B7F-3664-4A95-9572-A3E5871DFC06\" ascii nocase wide\n    ",
        "rule_name": "HackTool_MSIL_Rubeus_1_Wibble",
        "start_line": 1,
        "stop_line": 12,
        "strings": [
            {
                "modifiers": [
                    "ascii",
                    "nocase",
                    "wide"
                ],
                "name": "$typelibguid",
                "type": "text",
                "value": "658C8B7F-3664-4A95-9572-A3E5871DFC06"
            }
        ]
    }
]