DecTab: Editor behaves different than any other table like editor

[arimer]

Regular table like editors provide a End/Start Cell indicator (shown as grey line) at the beginning and ed of each table row.

Example:

However the editor of the DecTab concept does not have those indicators and therefore deletion/creation of new rows is cumbersome and behaves different than in any other table like editor.

[arimer]

Looks like this condition is evaluated into false in case Table.rowHeaders is used

[arimer]

Fixed in MPS-Extensions: https://github.com/JetBrains/MPS-extensions/pull/974