# autocomplete menu missing other options due to white space. How does space affect autocompletion?

I do not know if this was mentioned before. And I do not know if this is by design or not.

But I noticed when starting to insert an option, in the middle of other options, the pop-up menu that comes up suggesting a selection, is missing other possible selection. This happens when there is NO space after when the option is being inserted.

When there is a white space, then all the possible options to select from show up.

For example, given Plot[f[x], {x, 0, L0}, PlotStyle -> {Red}] and assume one want to insert Thickness[.01], just before Red in the above. After typing Thick, a pop-up menu comes up, but it only shows Thick as option. On the other hand, if one inserts a white space before the Red and now do the same thing, then the pop-up menu shows Thickness as another option.

L0 = 1;
f[x_] := Piecewise[{{Nothing, x < 0}, {1, x < L0/2}, {Nothing,x > L0}}];
Plot[f[x], {x, 0, L0}, PlotStyle -> {Red}]


Here is pic with no space

And now after adding a space before starting to insert the new option, it works

question is: Why when there was no space, it showed Thick only and not the rest?

I never knew that a space was needed in front of a command for it to pull the correct selection. Is this how it is supposed to work? Is space always needed when one wants to insert an option in the middle as in the above example?

btw, the same thing happens when using CTRL-K (manual auto-complete).

This is version 11.0.1 on windows. 64 bit.