apple/pkl · error · ParseException

name

Error message

name

What it means

Object member names in JSON must be double-quoted strings. In readObject, before each member the parser calls readName, which checks that the current character is '"'; if not, it throws expected("name"). This rejects unquoted or wrongly-typed keys such as JavaScript-style identifiers.

Source

Thrown at pkl-core/src/main/java/org/pkl/core/util/json/JsonParser.java:205

      if (!readChar(':')) {
        throw expected("':'");
      }
      skipWhiteSpace();
      handler.startObjectValue(object, name);
      readValue();
      handler.endObjectValue(object, name);
      skipWhiteSpace();
    } while (readChar(','));
    if (!readChar('}')) {
      throw expected("',' or '}'");
    }
    nestingLevel--;
    handler.endObject(object);
  }

  private String readName() throws IOException {
    if (current != '"') {
      throw expected("name");
    }
    return readStringInternal();
  }

  private void readNull() throws IOException {
    handler.startNull();
    read();
    readRequiredChar('u');
    readRequiredChar('l');
    readRequiredChar('l');
    handler.endNull();
  }

  private void readTrue() throws IOException {
    handler.startBoolean();
    read();
    readRequiredChar('r');
    readRequiredChar('u');

View on GitHub (pinned to f3efcbfc9b)

Solutions

1. Quote every object key with double quotes: {"name": 1} instead of {name: 1}.
2. Run the text through a strict-JSON formatter/validator before parsing to catch all unquoted keys at once.
3. If the data is a JS/Python literal, serialize it properly (JSON.stringify / json.dumps) rather than stringifying the value directly.
4. Catch ParseException and use its line/column to locate the offending key.

Example fix

// before
String json = "{name: \"pkl\"}"; // unquoted key
// after
String json = "{\"name\": \"pkl\"}";

// Java: detect unquoted object keys before parsing
static boolean hasUnquotedKeys(String json) {
  return java.util.regex.Pattern.compile("[{,]\\s*[A-Za-z_$][\\w$]*\\s*:").matcher(json).find();
}
if (hasUnquotedKeys(json)) throw new IllegalArgumentException("JSON object keys must be double-quoted");

try {
  parser.parse(json);
} catch (ParseException e) {
  if (e.getMessage().contains("name")) {
    throw new IllegalArgumentException("Unquoted or invalid object key at " + e.getLocation().line + ":" + e.getLocation().column, e);
  }
  throw e;
}

When it happens

Trigger: parse() on objects whose keys are not quoted: "{name: 1}", "{1: 'x'}" (numeric key), or any other token where a quoted name was required after '{' or ','.

Common situations: Pasting JavaScript object literals (or output of JS console.log / Python dict repr with single quotes) into a JSON config, hand-writing config files, template engines emitting {key: value} without quoting.

Understand the failure class

Background: JSON parse error: "Unexpected token" / "not valid JSON" / "failed to parse" — what JSON parsers are really complaining about — this error's family across 45 libraries.

Related errors

• ':'
• ',' or '}'
• '" + ch + "'
• Cannot parse `%s` as number.
• missingDelimiter

AI-assisted analysis of apple/pkl@f3efcbfc9b (2026-09-08). Data as JSON: /api/errors/8a9cc52515c5e97b. Report an issue: GitHub.