Method encode

src/main/java/net/starlark/java/lib/json/Json.java:142–256

(Object x)

    }

    private void encode(Object x) throws EvalException, InterruptedException {
      if (x instanceof Encodable) {
        x = ((Encodable) x).objectForEncoding(semantics);
      }

      if (x == Starlark.NONE) {
        out.append("null");
        return;
      }

      if (x instanceof String s) {
        appendQuoted(s);
        return;
      }

      if (x instanceof Boolean || x instanceof StarlarkInt) {
        out.append(x);
        return;
      }

      if (x instanceof StarlarkFloat fl) {
        if (!Double.isFinite(fl.toDouble())) {
          throw Starlark.errorf("cannot encode non-finite float %s", x);
        }
        out.append(x.toString()); // always contains a decimal point or exponent
        return;
      }

      // e.g. dict (must have string keys)
      if (x instanceof Map<?, ?> m) {
        // Sort keys for determinism.
        Object[] keys = m.keySet().toArray();
        for (Object key : keys) {
          if (!(key instanceof String)) {
            throw Starlark.errorf(
                "%s has %s key, want string", Starlark.type(x), Starlark.type(key));
          }
        }
        Arrays.sort(keys);

        // emit object
        out.append('{');
        String sep = "";
        for (Object key : keys) {
          out.append(sep);
          sep = ",";
          appendQuoted((String) key);
          out.append(':');
          try {
            encode(m.get(key));
          } catch (EvalException ex) {
            throw Starlark.errorf(
                "in %s key %s: %s", Starlark.type(x), Starlark.repr(key), ex.getMessage());
          }
        }
        out.append('}');
        return;
      }