OpenEuphoria

2. Re: Introspection?

• Posted by ChrisB (moderator) Mar 16, 2023
• 999 views

procedure Hello(sequence place) 
    puts(1, "Hello, " & place & "!\n") 
end procedure 
 
Hello("World") 

procedure Hello(sequence place) 
    puts(1, me() & ", " & place & "!\n") 
end procedure 
 
Hello("World") 

Hi

Are you asking for recursion, where a procedure calls itself?

procedure Hello(sequence place) 
    --puts(1, me() & ", " & place & "!\n") 
    Hello("Continent on ") 
    puts(1, place) 
end procedure 
 
Hello("World") 

This does wok but watch for the infinite loops. Set a break flag

integer break_flag = 0 
procedure Hello(sequence place) 
    if break_flag > 1 then return end if 
    break_flag += 1 
    
    Hello("Continent on ") 
    puts(1, place) 
 
end procedure 
 
Hello("World") 

4. Re: Introspection?

• Posted by ghaberek (admin) Mar 16, 2023
• 993 views

This is somewhat supported by using call_stack() from euphoria/debug/debug.e, the same way I demonstrated for variable_id. (These routines need more documentation for the 4.2 release.)

But it's only available in the interpreter and things can get weird if the interpreter inlines a call, which will be left out of the stack (you can disable this using without inline for a small performance loss).

Here's an example that sort-of recreates the C preprocessor macros like __LINE__ and __FILE__ (although they're functions here since we don't have macros per se).

include euphoria/debug/debug.e 
 
-- cs[1] is call_stack() itself 
-- cs[2] is the calling routine 
 
function __FUNC() 
    sequence cs = call_stack() 
    return cs[2][CS_ROUTINE_NAME] 
end function 
 
function __FILE() 
    sequence cs = call_stack() 
    return cs[2][CS_FILE_NAME] 
end function 
 
function __LINE() 
    sequence cs = call_stack() 
    return cs[2][CS_LINE_NO] 
end function 
 
-- heck, let's throw date and time in there too! 
 
constant MONTH = {"Jan","Feb","Mar","Apr","May", 
    "Jun","Jul","Aug","Sep","Oct","Nov","Dec"} 
 
function __DATE() 
    sequence d = date() 
    d[1] = d[1] + 1900 
    d[2] = MONTH[d[2]] 
    return sprintf( "%s %02d %d", {d[2],d[3],d[1]} ) 
end function 
 
function __TIME() 
    sequence d = date() 
    return sprintf( "%02d:%02d:%02d", d[4..6] ) 
end function 
 
procedure Hello(sequence place) 
    printf(1, "%s %s ", {__DATE(),__TIME()}) 
    printf(1, "%s:%d ", {__FILE(),__LINE()}) 
    printf(1, "%s, %s!\n", {__FUNC(),place}) 
end procedure 
 
Hello("World") 

Output:

$ eui /tmp/demo.ex 
Mar 16 2023 11:32:05 /tmp/demo.ex:21 Hello, World! 

I can: logging! I make heavy use of this feature in mvc/logger.e which will be ported to the standard library for Euphoria 4.2.

Right now you'd use it like this:

function max( atom x, atom y ) 
    log_trace( "x=%g, y=%g", {x,y} ) 
 
    return 0 
end function 
 
? max( 2, 3 ) 

Then call the interpreter with -D LOG_TRACE and get some fancy output complete with colored text (if writing to STDOUT or STDERR).

$ eui -D LOG_TRACE /tmp/demo.ex 
2023-03-16 11:20:00 TRACE max@/tmp/demo.ex:2 x=2, y=3 

In fact I should be able to combine that with what I demonstrated for variable_id() to provide cleaner and simpler per-call logging. Stay tuned for that.

-Greg

6. Re: Introspection?

• Posted by katsmeow Mar 17, 2023
• 777 views

Yanno, if type() could then know the name of the variable it was typechecking, and the name of the code block that called the typecheck, you could call code that executes if the typecheck fails, possibly fixing things up, and return something that makes less of a mess than an uncontrolled fatal error.

Or broadcast the variable has new contents. Or log time and what caused the data change. Or generate aux changes. So the Ai can know why it did that.

Kat