{
  "name": "get_feature",
  "type": "function",
  "description": "Returns the first feature of a layer matching a given attribute value.",
  "arguments": [ {"arg":"layer","description":"layer name or ID"},
                 {"arg":"attribute","description":"attribute name"},
                 {"arg":"value","description":"attribute value to match"}],
  "examples": [ { "expression":"get_feature('streets','name','main st')", "returns":"first feature found in \"streets\" layer with \"main st\" value in the \"name\" field"}]
}