{
  "name": "$x_at",
  "type": "function",
  "groups": ["GeometryGroup"],
  "description": "Retrieves a x coordinate of the current feature's geometry.",
  "arguments": [ {"arg":"i","description":"index of point of a line (indices start at 0; negative values apply from the last index, starting at -1)"}],
  "examples": [ { "expression":"$x_at(1)", "returns":"5"}
  ]
}