Describe the feature you'd like
Some interpreters have autocompletion and other handy tools that are activated when the user writes a TAB.

This makes sense for a real user interacting with the interpreter but if the user is writing an example in byexample he/she may write a TAB without notice and 99% he/she probably doesn't want an autocomplete happening during the execution of the example!.

This had already happen with the Ruby interpreter. In that case Ruby had (and has) an option to disable the readline mode and therefore the autocomplete and any other interactive feature on TAB.

But not all the interpreters will have a similar option.

The proposal is to replace the TABs within an example's source by spaces. If the user really wants a TAB to be injected, an option +allow-tabs should be set.

This feature will be non-backward compatible so it should be done for the next major release.