From: Florian Gross <flgr@...>
Date: 2004-11-18T01:13:15+09:00
Subject: Re: assert

Gavin Sinclair wrote:

> The question is: what
> method name is most acceptable?  'breakpoint_unless' is a bit long (I
> don't care, but others probably do).  Florian likes 'assume' but I
> think that's unclear -- at least it's not clear that it concerns
> breakpoints.

I actually consider that a feature. The interface isn't bound to 
Breakpoints either. It can make sense to have various actions on a 
failed assumption and it would be nice if other's could be fit into the 
same interface.

> So I thought of introducing a module, giving us
> 
>   Breakpoint.bp_unless
>   Breakpoint.bp_if
>   Breakpoint.bp_trap   # for trapping signals
> 
> and whatever other smart things people think of.  But that's not
> clearly a good idea.

The module already exists. (See Breakpoint.activate_drb) However it is a 
pain to have methods both inside the Module and in Kernel because that 
alters the caller's binding.

> But your post gave me this thought:
> 
>   breakpoint? 'b != 5'     # breakpoint if b != 5
> 
> The question mark suggests "conditional breakpoint", a term we're all
> used to from debuggers, I'm sure.  That might be the best idea yet.
> I'm just not sure which logic to use:
> 
>   breakpoint? 'b == 5'     # breakpoint unless b == 5
> 
> or
> 
>   breakpoint? 'b == 5'     # breakpoint if b == 5

Can we have this as an alias for assume()? I like it better than the 
breakpoint_unless/if forms.