Le lundi 24 octobre 2016 à 08:05 -0400, Isaiah Norton a écrit :
>
>
> On Monday, October 24, 2016, Angel de Vicente <angel.vicente.garrido@
> gmail.com> wrote:
> > Hi,
> >
> > I don't see it in the documentation, but I'm wondering if there is
> > a way
> > to have named nested loops, so that one can specify those names to
> > break
> > and continue, in order to have more control.
> >
> > In the following examples, continue always skips the remaining loop
> > for
> > j, while break terminates the j loop in the first example and
> > terminates
> > the single outer loop in the second (I guess it can be a bit
> > confusing
> > at first, but I can understand the design).
> >
> > ,----
> > | println("nested")
> > | for i in 1:3
> > | for j in 1:6
> > | if 2 < j < 4 continue end
> > | if j > 5 break end
> > | @printf("i: %i j: %i \n",i,j)
> > | end
> > | end
> > |
> > | println("single outer loop")
> > | for i in 1:3, j in 1:6
> > | if 2 < j < 4 continue end
> > | if j > 5 break end
> > | @printf("i: %i j: %i \n",i,j)
> > | end
> > `----
> >
> > But I'm used to Fortran, where one can do things like this (CYCLE
> > ==
> > continue ; EXIT == break), and you specify the loop that the
> > instruction
> > applies to.
> >
> > ,----
> > | INA: DO a = 1,1000
> > | INB: DO b=a+1,1000
> > | IF (a+b .GT. 1000) CYCLE INA
> > | INC: DO c=b+1,1000
> > | IF (a+b+c .GT. 1000) CYCLE INB
> > | IF (a+b+c .EQ. 1000 .AND. a**2 + b**2 .EQ. c**2) THEN
> > | PRINT*, a*b*c
> > | EXIT INA
> > | END IF
> > | END DO INC
> > | END DO INB
> > | END DO INA
> > `----
> >
> >
> > Is it possible now (or in the near future) to have named nested
> > loops in
> > Julia?
>
> No, and I'm not aware of any plan to support this. But you can create
> custom control flow with '@goto', so it could be probably be done
> with a macro.
A way to get out of multiple loops has actually been discussed, and the
consensus appears to be that it's a good idea:
https://github.com/JuliaLang/julia/issues/5334
Though it's not a high-priority feature since @goto works quite well.
Regards
> >
> > Thanks,
> > --
> > Ángel de Vicente
> > http://www.iac.es/galeria/angelv/
> >
