OpenEuphoria

2. Re: out of memory, even tho remembered nothing!

• Posted by DerekParnell (admin) Oct 18, 2012
• 1447 views

What happens when you change the program to either of these two alternatives ...

Alternative #1

include std/filesys.e -- for move, del, create, dir  
include std/console.e -- any_key()  
  
atom size = 0  
  
with trace  
  
  
sequence readfilename = "E:\\YAGO\\yago2core_20120109\\using.tsv"  
puts(1,"filesize actually read in with gets()\n\n")  
  
 
object junk, junk1 , junk2 , junk3, readfile  
-- odd something else: winders says : 7.28 GB 7,823,038,472 bytes)  
-- when the app crashed, it printed out : size = 9009698613  
-- how would it read 1.5 Gbytes past the end of the file?  
  
readfile = open(readfilename,"rb")  
while 1 do  
  junk = gets(readfile)  
  size += length(junk) -- out of memory here, size = 9009698613  
  junk = 0 
  puts(1,sprintf("%d",size)&"\r")  
end while  
  
  
close(readfile)  
 
puts(1,"\nwell, if i got here, there was no crash!\n\n")  
any_key()  
  
abort(0)  

Alternative #2

include std/filesys.e -- for move, del, create, dir  
include std/console.e -- any_key()  
  
atom size = 0  
  
with trace  
  
  
sequence readfilename = "E:\\YAGO\\yago2core_20120109\\using.tsv"  
puts(1,"filesize actually read in with gets()\n\n")  
  
procedure do_it() 
object junk, junk1 , junk2 , junk3, readfile  
-- odd something else: winders says : 7.28 GB 7,823,038,472 bytes)  
-- when the app crashed, it printed out : size = 9009698613  
-- how would it read 1.5 Gbytes past the end of the file?  
  
readfile = open(readfilename,"rb")  
while 1 do  
  junk = gets(readfile)  
  size += length(junk) -- out of memory here, size = 9009698613  
  puts(1,sprintf("%d",size)&"\r")  
end while  
  
  
close(readfile)  
 
end procedure 
 
do_it() 
puts(1,"\nwell, if i got here, there was no crash!\n\n")  
any_key()  
  
abort(0)  

4. Re: out of memory, even tho remembered nothing!

• Posted by jimcbrown (admin) Oct 18, 2012
• 1545 views

This was an enhancement to 4.0, to remove countless "if sequence() then ... length()" checks.

6. Re: out of memory, even tho remembered nothing!

• Posted by useless_ Oct 18, 2012
• 1475 views

So why can't i do this any more?

readfile = open(readfilename,"rb") 
junk = gets(readfile) 
while junk do 
  size += length(junk) 
  puts(1,sprintf("%d",size)&"\r") 
  junk = gets(readfile) 
end while 

It fails to run because junk isn't an atom. But then, if it was an atom, it would be -1, and not execute the while loop. So i still must do the type checks on it.

useless

8. Re: out of memory, even tho remembered nothing!

• Posted by jaygade Oct 18, 2012
• 1419 views

readfile = open(readfilename,"rb") 
junk = gets(readfile) 
while junk do 
  size += length(junk) 
  puts(1,sprintf("%d",size)&"\r") 
  junk = gets(readfile) 
end while 

Wouldn't this hang as an infinite loop if junk is -1 (a true value) anyway?

http://openeuphoria.org/docs/lang_loop.html#_156_whilestatement

10. Re: out of memory, even tho remembered nothing!

• Posted by useless_ Oct 18, 2012
• 1553 views

readfile = open(readfilename,"rb") 
junk = gets(readfile) 
while junk do 
  size += length(junk) 
  puts(1,sprintf("%d",size)&"\r") 
  junk = gets(readfile) 
end while 

I have previously considered any value (whether bit byte, char, string, etc) over 0 as TRUE and any value of zero or less to be FALSE. I refer you to:
http://i53.tinypic.com/x6c6fd.jpg

useless

12. Re: out of memory, even tho remembered nothing!

• Posted by jimcbrown (admin) Oct 18, 2012
• 1506 views

I think there's a good case for -1 being the same as true (since in two bits complement, -1 is the same as having all bits set to 1, whereas the integer 1 is simply a single bit set to 1 and the rest set to 0).

As I stated previously in this thread, no.

14. Re: out of memory, even tho remembered nothing!

• Posted by mattlewis (admin) Oct 18, 2012
• 1430 views

junk = gets(readfile) 
while sequence(junk) do 
  size += length(junk) 
  puts(1,sprintf("%d",size)&"\r") 
  junk = gets(readfile) 
end while 

This can be shortened slightly using a feature introduced in 4.0:

while sequence(junk) with entry do 
  size += length(junk) 
  puts(1,sprintf("%d",size)&"\r") 
entry 
  junk = gets(readfile) 
end while 

Execution of the loop always starts at entry, skipping the condition the first time through.

junk = gets(readfile) 
while not equal(-1,junk) do 
  size += length(junk) 
  puts(1,sprintf("%d",size)&"\r") 
  junk = gets(readfile) 
end while 

Yes, I typically check for a sequence, since you only get an atom returned from gets() after you've read all of the file.

Yeah, this is related to the long debated equals() vs = reform. But I don't see changing the truth value of atoms changing (the sequence as a boolean / truth value is more likely).

Matt

16. Re: out of memory, even tho remembered nothing!

• Posted by jimcbrown (admin) Oct 18, 2012
• 1499 views

junk = gets(readfile) 
while sequence(junk) do 
  size += length(junk) 
  puts(1,sprintf("%d",size)&"\r") 
  junk = gets(readfile) 
end while 

I just tried this, and it appears to work correctly for me. It gets the number of bytes in the file and reports it correctly, and then quits.

What behavior is it exhibiting for you that causes you to declare that it has failed?

You already know this, but just so other readers of this thread are clear: gets() returns a value that is equal to the public constant EOF in io.e, but it doesn't actually use that constant. It merely returns -1.

I don't see how.

Agreed. When I run your code, it seems to confirm that this is the case (that -1 is not a sequence).

I disagree. -1 should be TRUE since -1 is the set of bits such that all bits are equal to 1.

junk = gets(readfile) 
while not equal(-1,junk) do 
  size += length(junk) 
  puts(1,sprintf("%d",size)&"\r") 
  junk = gets(readfile) 
end while 

Avoid horrors like what? Why must this be used, instead of your original code above?

Same here. I'm sure we could enhance the parser so that, if gets() is being called inside an if or while statement (or something akin to that) it returns 0 on EOF instead of -1, as well as making any sequence from gets() counted as a TRUE value.

I'd hate to see -1 become a FALSE value, though.

18. Re: out of memory, even tho remembered nothing!

• Posted by DerekParnell (admin) Oct 18, 2012
• 1443 views

I suspect that you have misunderstood the concept of OBJECT. The gets function returns an object. When that object contains a sequence, it's the read data and when that object contains an atom it signifies end-of-file. The CONSTANT called EOF is defined as an OBJECT with the ATOM value of -1. OBJECTs are containers that can contain either atoms or sequences.

The code you posted as not working will not work if 'junk' is defined as a sequence variable, but if defined as an object then it will work. The following should be working correctly ...

include std/console.e 
object junk 
junk = gets(readfile) 
while sequence(junk) do 
  size += length(junk) 
  display(size) --> simplier than ... puts(1,sprintf("%d",size)&"\r") 
  junk = gets(readfile) 
end while 

20. Re: out of memory, even tho remembered nothing!

• Posted by useless_ Oct 18, 2012
• 1447 views

junk = gets(readfile) 
while sequence(junk) do 
  size += length(junk) 
  puts(1,sprintf("%d",size)&"\r") 
  junk = gets(readfile) 
end while 

It read a gigabyte past the end of the file again. Eu version 4.0.4.

useless

22. Re: out of memory, even tho remembered nothing!

• Posted by mattlewis (admin) Oct 18, 2012
• 1397 views

junk = gets(readfile) 
while sequence(junk) do 
  size += length(junk) 
  puts(1,sprintf("%d",size)&"\r") 
  junk = gets(readfile) 
end while 

Yes, -1 is an atom. Yes, gets() returns an atom on EOF. I've used that idiom for years.

Matt

24. Re: out of memory, even tho remembered nothing!

• Posted by DerekParnell (admin) Oct 18, 2012
• 1365 views

With respect, may I suggest that you are not running the program code you think you're running.

How about updating the code you think you are running with a special message to identifiy it, and if it is still failing, post the entire code here for someone else to reproduce your issue.

26. Re: out of memory, even tho remembered nothing!

• Posted by mattlewis (admin) Oct 19, 2012
• 1359 views

That sounds likely at this point.

Matt

28. Re: out of memory, even tho remembered nothing!

• Posted by useless_ Oct 19, 2012
• 1349 views

public constant EOF = {-1} 

I am unsure A) if you are saying that is the fix or not, B) if that is the fix or not, C) if i should risk breaking anything else by changing that. Because i don't know if there is a special way constant handles assignments using ( ).

useless

30. Re: out of memory, even tho remembered nothing!

• Posted by DerekParnell (admin) Oct 25, 2012
• 1274 views

This is a throwback to a defensive programming practice by C coders. In C, when defining a macro it used to be a good idea to enclose the macro's definition in parenthesis to prevent accidental text appending in the source code.

#define EOF = -1 
#define ABC = *2 
#define XYZ = EOF ABC 

#define EOF = (-1) 
#define ABC = (*2) 
#define XYZ = EOF ABC