Question: Autocomplete self defined variables and functions

Hello.

I have started using textastic.

This is really great app to work with, but I couldn’t figure out if there is function to autocomplete my self defined variables and functions.

I know there already exists a function to autocomplete standard functions, for example, 

when you type “func…” and then tap Tab key, there appears:
function name() {

}

or “al” and tab then alert( )

but for var someThing, or function someFunc(){},

even if you type “some…” it does not show option to select from “someThing” or ”someFunc”.

we usually use self stated variables and functions for many times, and each time we are anxious for mistyping.

And so basically superior code editor has a function to autocomplete those - often little bit lengthy - names.

I hope anyone tell me how to enable that functionality.

Thank you.