Inferring headers

src/cmd/jsonl.rs

@@ -32,25 +32,69 @@ struct Args {
  flag_output: Option<String>,
 }
 
-fn infer_headers(value: Value) -> Option<Vec<String>> {
- let mut headers: Vec<String> = Vec::new();
+fn recurse_to_infer_headers(value: Value, headers: &mut Vec<Vec<String>>, path: Vec<String>) {
+ match value {
+ Value::Object(map) => {
+ for (key, value) in map.iter() {
+
+ match value {
+ Value::Null |
+ Value::Bool(_) |
+ Value::Number(_) |
+ Value::String(_) => {
+ let mut full_path = path.clone();
+ full_path.push(key.to_string());
+
+ headers.push(full_path);
+ },
+ Value::Object(_) => {
+ let mut new_path = path.clone();
+ new_path.push(key.to_string());
+
+ recurse_to_infer_headers(value.to_owned(), headers, new_path);
+ }
+ _ => {}
+ }
+ }
+ },
+ _ => {
+ headers.push(vec![String::from("value")]);
+ }
+ }
+}
+
+fn infer_headers(value: Value) -> Option<Vec<Vec<String>>> {
+ let mut headers: Vec<Vec<String>> = Vec::new();
+
+ recurse_to_infer_headers(value, &mut headers, Vec::new());
 
  return Some(headers);
 }
 
 pub fn run(argv: &[&str]) -> CliResult<()> {
  let args: Args = util::get_args(USAGE, argv)?;
+ let mut wtr = Config::new(&args.flag_output).writer()?;
 
  let rdr: Box<dyn BufRead> = match args.arg_input {
  None => Box::new(BufReader::new(io::stdin())),
  Some(p) => Box::new(BufReader::new(fs::File::open(p)?))
  };
 
+ let mut headers_emitted: bool = false;
+
  for line in rdr.lines() {
  let value: Value = serde_json::from_str(&line?)
  .expect("Could not parse line as JSON!");
 
- println!("{:?}", value);
+ if !headers_emitted {
+ if let Some(headers) = infer_headers(value) {
+ let headers = headers.iter().map(|v| v.join(".")).collect::<Vec<String>>();
+ let headers = csv::StringRecord::from(headers);
+ wtr.write_record(&headers)?;
+ }
+
+ headers_emitted = true;
+ }
  }
 
  Ok(())