NRQL Parser

Peg grammar (using pegjs) for New Relic
Insight's query language.

``
$ ./bin/nrql-parse -e "SELECT uniqueCount(user) FROM PageView WHERE userAgentOS = 'Mac' FACET countryCode LIMIT 20 SINCE 1 day ago"


{
"type": "Select",
"selects": [
{
"type": "SelectClause",
"value": {
"type": "FunctionExpression",
"name": "uniqueCount",
"arguments": [
{
"type": "Identifier",
"name": "user"
}
]
}
}
],
"from": {
"type": "Identifier",
"name": "PageView"
},
"where": {
"type": "WhereCondition",
"condition": {
"attribute": {
"type": "Identifier",
"name": "userAgentOS"
},
"op": "=",
"right": {
"type": "StringLiteral",
"value": "Mac"
}
}
},
"facet": {
"type": "Identifier",
"name": "countryCode"
},
"limit": {
"type": "FloatLiteral",
"value": 20
},
"since": {
"type": "TimeAgo",
"duration": {
"type": "duration",
"quantity": {
"type": "FloatLiteral",
"value": 1
},
"unit": "d"
}
}
}
``