1. Re: Short Circuiting + Return in procedures
- Posted by Daniel Berstein <daber at PAIR.COM>
Jun 25, 1998
-
Last edited Jun 26, 1998
-----Original Message-----
De: Lmailles at AOL.COM <Lmailles at AOL.COM>
Para: EUPHORIA at cwisserver1.mcs.muohio.edu
<EUPHORIA at cwisserver1.mcs.muohio.edu>
Fecha: jueves 25 de junio de 1998 14:14
Asunto: Re: Short Circuiting + Return in procedures
>Jiri wrote that you can and always will be able to use return to escape
from
>procedures. This is funny because I recently got clobbered by the
interpreter
>for trying to "exit" from a procedure (Yes, I guess I learnt it from
[excuse
>my language] QBasic). However, we have
>
>"exit"
>from loops
>"return"
>from rountines and
>"abort"
>from main routine.
>
>Is this not an unnecessary complication ? Would it hurt anyone to allow
"exit"
>from a procedure Rob ? I think that having "return x" in a procedure would
be
>extremely confusing for a newbie and hints of other inferior languages
which
>allow you to do naughty things like not returning values from functions.
You can use abort() from anywhere in your source. I usually do it. Example:
constant error = {"Usage: me.exe <file_name>\n",
"Error opening file\n"
}
integer fn
function open_file(sequence arg)
if length(arg) < 3 or length(arg) > 3 then
puts(1,error[1])
abort(-1)
else
fn = open(arg[3],"rb")
if fn = -1 then
puts(1,error[2])
abort(-1)
end if
end if
end function
fn = open_line(command_line())
-- Rest of code ....
Regards,
Daniel Berstein
daber at pair.com
