OpenEuphoria

Differences between type_checks(was RE: haha very funny)

• Posted by bensler at mail.com Oct 22, 2001
• 365 views

Just curious,

   Would there be any difference in speed between type checking an 
integer and an atom?

   From what I know, it's faster to type check an integer, but I would 
THINK it would be faster to type check an atom since there are less 
restictions for it.

   How about type checking an object? I know it's redundant, but you can 
do it. Does object() actually do any tests, or does it just return TRUE 
every time? Or does object() actually type check a variable to verify 
that it is CAST as an object?

Chris



Derek Parnell wrote:
> The documentation states that the dir() function can return either an 
> atom or a sequence. This is consistent with other library calls too.
> 
> >From the docs...
> 
>   Syntax: include file.e
>           x = dir(st)  
> 
> and from the Part II - Library Routines Introduction...
> 
>  To indicate what kind of object may be passed in and returned, the  
> following prefixes are used: 
> 
> 
>  x - a general object (atom or sequence) 
>  s - a sequence 
>  a - an atom 
>  i - an integer 
>  fn - an integer used as a file number 
>  st - a string sequence, or single-character atom 
> 
> Anyhow, this is how I use the dir() function...
> 
>   object d
>   d = dir(FileSpec)
>   if atom(d) then
>     -- 'FileSpec' doesn't exist.
>   else
>     for i = 1 to length(d) do
>        -- Process the files and directories...
>     end for
>   end if
> 
> ---------
> Derek.
> 
> 
> euman at bellsouth.net wrote:
> > sequence dirs
> >     dirs = dir(FileSpec)
> >     for i = 1 to length(dirs) do
> > 
> > dirs will actually contain file or directory info if there are any files 
> > 
> > or directories
> > 
> > This from the Euphoria docs:
> > 
> > d = dir(current_dir()) -- this says right up front dir( ) returns a 
> > sequence doesnt it!
> > 
> > -- d might have:
> >   {
> >     {".",    "d",     0  1994, 1, 18,  9, 30, 02},
> >     {"..",   "d",     0  1994, 1, 18,  9, 20, 14},
> >     {"fred", "ra", 2350, 1994, 1, 22, 17, 22, 40},
> >     {"sub",  "d" ,    0, 1993, 9, 20,  8, 50, 12}
> >   }
> > 
> > OK, very well then, but when it doesnt contain info the return value is 
> > -1 which
> > gives us a type_check error...
> > 
> > OK then, we name dirs as an object and because we look for a length to 
> > dirs
> > next we get this error message > length of an atom not defined.....huh
> > 
> > this from the Euphoria Docs
> > If there is no file or directory with this name then -1 is returned
> > 
> > OK, if we keep the dir defined as an object and run a test to make sure 
> > dirs is not -1 like 
> > this:
> > 
> > if dir(FileSpec) != -1 then we get  true/false condition must be an ATOM
> > 
> > and damn I could list several other error messages and code but you all 
> > get the point now.
> > 
> > We are so restricted it's not funny...
> > I'll go to bed now.....later yall.
> > 
> > Euman
> > euman at bellsouth.net
> > 
> >