# Error in generated Typescript
**URL:** https://discuss.codemirror.net/t/error-in-generated-typescript/7382
**Category:** Lezer
**Created:** [November 7, 2023, 9:00pm UTC](https://discuss.codemirror.net/t/error-in-generated-typescript/7382 "2023-11-07T21:00:02Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@jpelay](https://discuss.codemirror.net/u/jpelay)
#### Post date: [November 7, 2023, 9:00pm UTC](https://discuss.codemirror.net/t/error-in-generated-typescript/7382/1 "2023-11-07T21:00:02Z")
Hi! I’m currently trying to generate a parser in Typescript, but the option is either not working or I don’t know how to use it.
I’m using the command line too `lezer-generator` to generate my grammars, this is the command I’m using:
```auto
npx lezer-generator --typeScript level17.grammar -o level17-parser.ts
```
But when generating the parser and then trying to compile the resulting TypeScript, it tells me this:
```auto
level17-parser.ts:20:87 - error TS2554: Expected 1 arguments, but got 2.
20 specialized: [{term: 36, get: (value: any, stack: any) => (specializeKeyword(value, stack) << 1), external: specializeKeyword},{term: 36, get: (value: any, stack: any) => (extendKeyword(value, stack) << 1) | 1, external: extendKeyword, extend: true}],
```
I’m using two custom specializers `specializeKeyword` and `extendKeyword`, and maybe that has something to do? The code does work, but when trying to compile it, is just Typescript that returns this error. Any help would be appreciated
---
### Author:  [@jpelay](https://discuss.codemirror.net/u/jpelay)
#### Post date: [November 7, 2023, 9:06pm UTC](https://discuss.codemirror.net/t/error-in-generated-typescript/7382/2 "2023-11-07T21:06:25Z")
Nevermind! It was actually my own fault for not providing a second argument to my specializer! My apologies.
Also, I’ve been working with Lezer for the past month and is been truly amazing, love Lezer and CodeMirror.