Maple does not have a GOTO. I do ?goto and nothing comes up (I thought it did at one point, but it seems to be gone). I also saw 

99052-How-To-Write-Procedures-That-Use-Go-To-In-Maple

GOTO is considered bad, and I agree in general. But there ONE very good use for GOTO which can't be easily replaced, which is having a common exit label. (at one work place sometime ago, this was actually the only recommened use for it in the programming guidelines. and I agree.)

Without this, one ends up with deep if then else if then else if then else., etc....

But having a common exit, where one can do common clean up things is very good. This reduced code duplication and actually makes the logic more clear.

Here is just some silly example to  illustrate

foo:=proc(x)
  if x=10 then
     .....
    close file, print common message
    return(final_result);
  fi;

  if x=12 then
     .....
    close file, print common message
    return(final_result);
  fi;

 etc...

end proc;

With common exit point, one could do

foo:=proc(x)
   if x=10 then 
      .....
     final_result :=...
     goto common_exit;
   fi;

   if x=12 then 
      .....
     final_result :=...
     goto common_exit;
   fi;

common_exit:
   close file; 
   print common message;
   return(final_result);

end proc;

The alternative is to have deep  nested if then else, like this

foo:=proc(x)
    if x=10 then 
       ..... 
       final_result :=...;
    else
         if x=12 then 
            ..... 
            final_result :=...;
         else
             if x= 20 then
                .....
                final_result :=...;
             fi;
         fi;
   fi;

  close file; 
  print common message;
 return(final_result);
end proc;

For complicated logic, I do not think the last case is better than the second one using GOTO.

The second case also eliminates duplicate code as was done in first case. Also first case has multiple return points from the proc, which is not good. As having one common return point is better.

Why was goto removed from Maple? Can one still use it somehow? Where is the documenation for it?

update

goto seems to be there. I did not think of trying, since ?goto did not show it. But now I found I could do this and it works

foo:=proc()
  local x;
  x:=10;
  goto(common_exit);
  x:=20;
common_exit:
  print(x);
end proc;

So please Maplesoft., do not remove GOTO.

I am stumped at this.

I made a proc A which takes arguments using keywords. When I call A directly, it works. When I pass the argument I want to call A with to another proc B, and then from B call A with that argument, it fails. Maple tells me that it missing arguments. Here is a MWE

restart;
procA := proc({the_equation::`=`:=NULL})
  print("it worked, you passed in ", the_equation);
end proc:

procB :=proc(the_equation)
  print("inside procB, the equation is ", the_equation);
  procA('the_equation'=the_equation); 
end proc:

Now, calling procA directly, works

the_equation:= y=3:
procA('the_equation'=the_equation);

              "inside procA, you passed in ", y = 3

But when caling procB, and then have procB call procA, the argument passed in is NULL

procB(the_equation);

                  "inside procB, the equation is ", y = 3
                 "inside procA, you passed in "  <=== WHY NULL?

I must be doing something wrong, I just do not see it.

I am learning argument passing using keyword, which I like more than positional arguments.

I wanted to have an argument which should be only an equation, to be passed in.

So I typed

restart;
foo:=proc({the_equation::`=`:=NULL}) 
   print (the_equation); 
end proc;

And this works when calling it as

the_equation := y=5:
foo('the_equation'= the_equation);

But it does not work, if I put the value of "the_equation" variable in the call itself, like this

foo('the_equation'= y=5);
Error, `=` unexpected

Which is a little strange. So it seems frontend does not like to parse it. A workaround (other than using a variable) is

foo('the_equation'= 'y=5');

Just found it a little odd, that using a variable for y=5 works, but not putting value of the variable  directly there. I thought they should be equivalent.

Since I expected Maple to evaluate and replace the variable "the_equation" back by "y=5" so we end up with the call "foo('the_equation'= y=5);".

But that is not what seems to happen in Maple.

Question is, should the call foo('the_equation'= y=5);  have failed parsing?

Update: rebooting the PC fixed this error for me. Now help comes up OK.

original question:

I am on windows 7, home editon, running Maple 2018.

For some reason, now each time I tried to get help, I get the message that it lost connection with server. I closed Maple, started it up again, and same error happens. Movie below.

This also happend from new worksheet also Each time I type ?anything I get the above.

Any idea what can cause it? and where I should look for errors?

I did not nothing before this to anything on system. Was just editing some worksheet which opens fine. It is only help that seems to be having hard time.

I downloaded alglib from 

http://algo.inria.fr/libraries/obsolete-releases.html

Downloaded the .mla and the .hdb files. Put them in current directory where my worksheet .mw is.

Opened the .mw and typed

restart;
libname := currentdir(), libname;
_algolibcontent();

Content of algolib (version 14.0), as of October 2010:

+ encyclopedia.            [Written by Stéphanie Petit, with contributions by Bruno Salvy and Michèle Soria.]
+ gdev.                [Written by Bruno Salvy.]
+ gfun (version 3.53).        [Maintained and extended by Bruno Salvy, with contributions by Ludovic Meunier, Marc Mezzarobba, Marni Mishna, and Eithne Murray, original version by Bruno Salvy and Paul Zimmermann.]
+ Holonomy (version 3.4).    [Written by Frédéric Chyzak.]
+ MAD (version 1.445).        [Written by Ludovic Meunier.]
+ Mgfun (version 4.1).        [Written by Frédéric Chyzak, with contributions by Shaoshi Chen, Cyril Germa, Lucien Pech, and Ziming Li.]
+ MultiSeries.            [Written by Bruno Salvy.]
+ regexpcount (version 1.5).    [Written by Pierre Nicodème.]
 

Ok. Now how to obtain help? I can call one of its functions, like this

MADLaTeX:-latex(1/2);

    \frac{1}{2}

But I do not know how to find help on MADLaTeX:-latex since ?MADLaTeX does nothing and ?MADLaTeX:-latex does nothing. 

How to obtain the help pages for this package? I looked online and do not see anything. I do not know what to do with the .hdb file that I downloaded. I am using Maple 2018 and it does not seem to support .hdb files anyway. 

Does I need to go through all the conversion steps described in

https://www.maplesoft.com/support/help/Maple/view.aspx?path=HelpTools%2fMigrate

just to see help on one function? 

I just need to find how to call is Latex function and if it has any options. Any one knows an online page that have these on it?