exit should return from a proc to Toplevel

[gorzelc@…]

gorzel wrote in Ticket #100

 >>   It would have been easier to extend the already existing command "exit".

hannes wrote

> no exit and ERROR are very diffrent. 
> In principle, ERROR is an runtime error. 

Yes, but I would like to have a command that leaves a proc from inside, without going through the internal error-machinery.

Compare with the command break; which can be used to leave a loop.

As quit; and exit; behave the same: they leave Singular entirely, I suggest to change the exit in the following way:

When exit is called from inside a proc,

it should leave the proc and return silently to the Toplevel,

when called on the Toplevel, it may leave Singular entirely.

The command quit; shall stay as it is and always leave Singular, but

the behaviour of exit; should depend on the level from which it is called.

(Additionally, exit may have a string as argument, that it displays, (compare with exit in my-sql) and this could then serve as the ERROR command. This is what I had in mind, when writing

It would have been easier to extend the already existing command "exit".)

[hannes]

if this exit should be like an error, use ERROR. If not: what to do if called inside a proc, which should return a value? This may also be indirect: exit called within proc which was called inside a proc, which should return a value etc.