Re: Bug with unset variables

[Felipe Contreras <felipe.contreras@xxxxxxxxx>]

On Fri, Nov 27, 2020 at 9:44 AM Daniel Shahaf <d.s@xxxxxxxxxxxxxxxxxx> wrote:
>
> Felipe Contreras wrote on Wed, Nov 25, 2020 at 02:46:40 -0600:
> > Maybe there's a better way to describe this fact. Maybe Git's notion
> > of logically separate changes [1] helps (e.g. you should not mix
> > whitespace cleanups with functional changes). But the fact is that in
> > virtually all languages (and bash and ksh) there's an idiom to declare
> > a local variable and *only* declare a local variable (not do anything
> > else).
> >
> > Can we at least agree on that? In zsh typeset does *two* things.
>
> I'd rather say that «typeset» does one thing — it ${verb}s a variable
> (for some value of $verb) — and the zsh data model doesn't feature
> a "Not really a value" value, so the variable necessarily gets _some_
> value, like «int foo;» in C.

If it's really one thing, then why does adding it in the example above
changes the behavior in *two* ways?

  func () {
    [[ -n "$1" ]] && var=$1
    dosomething ${var-other}
  }

  func () {
    typeset var
    [[ -n "$1" ]] && var=$1
    dosomething ${var-other}
  }

-- 
Felipe Contreras