{"record":{"id":"e523518204365dcd","repo":"stanfordnlp/CoreNLP","slug":"expecting-begin-block-got-end-of-file","errorCode":null,"errorMessage":"expecting BEGIN block; got end of file.","messagePattern":"expecting BEGIN block; got end of file\\.","errorType":"exception","errorClass":"RuntimeException","httpStatus":null,"severity":"error","filePath":"src/edu/stanford/nlp/parser/lexparser/LexicalizedParser.java","lineNumber":506,"sourceCode":"      out.println(prefix + \"DEPENDENCY_GRAMMAR\");\n      if (dg != null) {\n        dg.writeData(out);\n      }\n      out.println();\n      log.info(\".\");\n\n      out.flush();\n      out.close();\n      log.info(\"done.\");\n    } catch (IOException e) {\n      log.info(\"Trouble saving parser data to ASCII format.\");\n      throw new RuntimeIOException(e);\n    }\n  }\n\n  private static void confirmBeginBlock(String file, String line) {\n    if (line == null) {\n      throw new RuntimeException(file + \": expecting BEGIN block; got end of file.\");\n    } else if (! line.startsWith(\"BEGIN\")) {\n      throw new RuntimeException(file + \": expecting BEGIN block; got \" + line);\n    }\n  }\n\n  protected static LexicalizedParser getParserFromTextFile(String textFileOrUrl, Options op) {\n    try (BufferedReader in = IOUtils.readerFromString(textFileOrUrl)) {\n      Timing tim = new Timing();\n\n      String line = in.readLine();\n      confirmBeginBlock(textFileOrUrl, line);\n      op.readData(in);\n\n      line = in.readLine();\n      confirmBeginBlock(textFileOrUrl, line);\n      Index<String> stateIndex = HashIndex.loadFromReader(in);\n\n      line = in.readLine();","sourceCodeStart":488,"sourceCodeEnd":524,"githubUrl":"https://github.com/stanfordnlp/CoreNLP/blob/1b7edd19c4d0d7b1f13a2591425b9b60a0b1af7a/src/edu/stanford/nlp/parser/lexparser/LexicalizedParser.java#L488-L524","documentation":"confirmBeginBlock validates the first line read from a text-format parser file: text grammars must start with a 'BEGIN' block. A null line means the file ended before any block was found; a non-BEGIN line means the file doesn't start with the expected header. Either way the file is not a valid text grammar.","triggerScenarios":"getParserFromTextFile reading an empty file, a URL that returned empty content, or a file whose first line is not 'BEGIN' (e.g. a serialized parser or a text grammar from an incompatible version).","commonSituations":"Passing a .ser.gz model to a text-grammar loading path, mistyping a URL so it yields empty content, or truncating the grammar file.","solutions":["Confirm the file is a text grammar starting with a 'BEGIN' line, not a serialized model; use loadModel for serialized files.","Check the path/URL resolves to a non-empty resource.","Regenerate the text grammar with the same parser version if the format changed."],"exampleFix":"// before\nLexicalizedParser.getParserFromTextFile(\"english.ser.gz\", op); // serialized file\n// after\nLexicalizedParser lp = LexicalizedParser.loadModel(\"english.ser.gz\");","handlingStrategy":"validation","validationCode":"String firstLine = new BufferedReader(new InputStreamReader(url.openStream())).readLine();\nif (firstLine == null || !firstLine.startsWith(\"BEGIN\")) throw new IllegalArgumentException(\"Not a text grammar file: \" + file);","typeGuard":null,"tryCatchPattern":"try { parser = getParserFromTextFile(file, op); } catch (RuntimeException e) { parser = LexicalizedParser.loadModel(file); }","preventionTips":["Confirm file type before choosing the loading API (text grammar vs serialized model)","Verify URLs/paths resolve to non-empty files"],"tags":["file-format","text-grammar","parser","malformed-input"],"backgroundTag":"file-read-failed","analyzedSha":"1b7edd19c4d0d7b1f13a2591425b9b60a0b1af7a","analyzedAt":"2026-09-10T02:24:07.274Z","contentChangedAt":"2026-09-10T02:24:07.274Z","schemaVersion":2},"datasetVersion":"2026-09-15T23:17:13.987Z"}