OpenEuphoria

RE: "eval()" commands/crash callbacks/ect. for Euphoria 2.5?

• Posted by CoJaBo <cojabo at suscom.net> Jan 15, 2004
• 377 views

Okay, I'll try once more
(Am I going crazy or are there "=##"s every were?!?):

I beleive that at least the first two should be added to Eu 2.5.
Anyone else agree?

Please take them into consideration.


"eval()" commands:
I would really like to see a way to do an "eval()" type command.
Many other languages have something like this.

eval(sequence eval_commands,integer global_type,integer crash)
eval_commands is a sequence of commands
global_type is:
0-No routines/varibles (even global) exist in main program
1-Only routines/varibles declared as global exist in main program
2-All routines/varibles exist in main program

if crash is true, if it encounters an error (like 1/0) than the
program dies with (or a crash routine, see below) ex.err, otherwise, it 
returns an error 
code(like 5 for divide by 0,see below)


Example:
integer a,global_type
sequence eval_commands

eval_commands="
include incl_file.e--should allow including(This could be used 
--instead of complex "dynamic includeing" libraries)
if a then
?a
end if"

a=7
var_type=1

?eval(eval_commands,global_type,0)
Displays:
7(value of a)
0(eval encountered no errors)

____________________________________________________________
Crash callback
A way to setup a callback function would allow programs to save user 
data before exiting
with ex.err

set_crash(integer routine_id)
routine_id is the routine id of the function
it calls the function with an error code(like 5 for divide by 0),
a sequence with info about the error(like a line #, invalid subscript, 
ect.)
and a text string with the complete text error message(
"test.ex:3
attempt to divide by 0")

if the function returns -1, ignore the error

Example:
function oncrash(integer err_code,sequence info,sequence msg)
if err_code=34 then--this error can be ignored in this program
return -1
end if
save_all_important_data()
return 0
end function
set_crash(routine_id("oncrash"))

_________________________________________________

CoJaBo wrote:
> 
> 
> I beleive that at least the first two should be added to Eu 2.5.
> Anyone else agree?
> 
> Please take them into consideration.
> 
> 
> "eval()" commands:
> I would really like to see a way to do an "eval()" type command.
> Many other languages have something like this.
> 
> eval(sequence eval_commands,integer global_type,integer crash)
> eval_commands is a sequence of commands
> global_type is:
> 0-No routines/varibles (even global) exist in main program
> 1-Only routines/varibles declared as global exist in main program
> 2-All routines/varibles exist in main program
> 
> if crash is true, if it encounters an error (like 1/0) than the
> program dies with (or a crash routine, see below) ex.err, otherwise, 
> it=20
> returns an error=20
> code(like 5 for divide by 0,see below)
> 
> 
> Example:
> integer a,global_type
> sequence eval_commands
> 
> eval_commands=3D"
> include incl_file.e--should allow including(This could be used=20
> --instead of complex "dynamic includeing" libraries)
> if a then
> ?a
> end if"
> 
> a=3D7
> var_type=3D1
> 
> ?eval(eval_commands,global_type,0)
> Displays:
> 7(value of a)
> 0(eval encountered no errors)
> 
> ____________________________________________________________
> Crash callback
> A way to setup a callback function would allow programs to save user=20
> data before exiting
> with ex.err
> 
> set_crash(integer routine_id)
> routine_id is the routine id of the function
> it calls the function with an error code(like 5 for divide by 0),
> a sequence with info about the error(like a line #, invalid 
> subscript,=20
> ect.)
> and a text string with the complete text error message(
> "test.ex:3
> attempt to divide by 0")
> 
> if the function returns -1, ignore the error
> 
> Example:
> function oncrash(integer err_code,sequence info,sequence msg)
> if err_code=3D34 then--this error can be ignored in this program
> return -1
> end if
> save_all_important_data()
> return 0
> end function
> set_crash(routine_id("oncrash"))
> 
> _________________________________________________
> Kat wrote:
> >=20
> >=20
> > On 14 Jan 2004, at 1:27, CoJaBo wrote:
> >=20
> > >=20
> > >=20
> > > I don't see why Euphoria can't support at least the first two.
> > >=20
> > > A way to recvor from errors is almost absolutly nessescery in=20
> > > programs=3D20
> > > that have a lot of user data when they might crash.(like Win32Lib IDE)
> > >=20
> > > Almost all other languages I've used had an "eval()" command, this=20
> > > would=3D
> > > =3D20
> > > be very useful in Euphoria.
> >=20
> > I agreed=3D20 with=3D20 you!!=3D20 Please=3D45 explain=3D60 this=3D50to 
> > R=
> DS!!=3D98
> > =3D74
> > =3D-3456.2
> > Kat=3D65
> >=20
> >=20
<snip>