Customizing skeleton of if -- then -- else

[psibi]

Is there a way to customize skeleton of if then else such that it becomes:

if undefined
then undefined
else undefined

I know that it doesn't comply with your style guide, but for simple cases it seems an overkill.

[ivan-m]

I think it's done with the indentations so it also works in do-blocks, otherwise more context would be needed to determine whether to indent the then and else or not.