Sample contents of a .txt file on my Mac:

```
This is sentence A.
This is sentence B.
This is sentence C.
This is sentence D.
This is sentence E.

```

I want to implement a subroutine, like this: 

```
writeTextAtSpecificLine(("This is the newcomer sentence." & linefeed), 4)

```

so that, the text file would consequently look like this:

```
This is sentence A.
This is sentence B.
This is sentence C.
This is the newcomer sentence
This is sentence D.
This is sentence E.

```

---

I know that I can accomplish my desired result by making each line of the text file its own item in an AppleScript `list` object, like so:

```
set theIndividualLinesOfTextFileAsList to paragraphs of (read theFilepathOfTxtFile)

```

I could then split the `list`, based on the desired line number, and then add it all back together.

But, does a more efficient method exist? 

My real .txt file is much longer than the sample content above.