Question on Read function

[Lincoln Bauman]

I recently ran across this, I created a work around but am wondering if someone can provide an explanation.
All 10 character strings:

Command: (type(read "2146000000"))
INT

Command: (type(read "2147000000"))
INT

Command: (type(read "2148000000"))
REAL

The code I was working on was expecting an INT value but failed when we added 10 digit values to some of our data.

Thanks.

[Tharwat]

Hi,

You can try this function to work around that function's issue.

(defun type_ (str)  (if (numberp (read str))
    (if (or (vl-string-search "." str)
            (vl-string-search "," str)
        )
      'REAL 'INT)
  )
)

[Lincoln Bauman]

Hi,

You can try this function to work around that function's issue.

(defun type_ (str)  (if (numberp (read str))
    (if (or (vl-string-search "." str)
            (vl-string-search "," str)
        )
      'REAL 'INT)
  )
)

Thanks for the reply.
I also noticed similar odd behavior with the ATOI function.
Apparently there's some limitation as to the size of the number involved.

Command: (atoi "2146000000")
2146000000

Command: (atoi "2147000000")
2147000000

Command: (atoi "2148000000")
2147483647

Command: (atoi "8452657842")
2147483647

[did-ave]

Coucou, Hello

it is not the function "read" that is in question...

it's because you've reached the limit of integer numbers

AutoLISP integers are 32-bit signed numbers with values ranging from +2,147,483,647 to -2,147,483,648.
Some functions through, only accept 16-bit numbers ranging from +32767 to -32678.
When you explicitly use an integer, that value is known as a constant. Numbers such as 2, -56, and 1,200,196 are valid integers.
If you enter a number that is greater than the maximum integer allowed (resulting in integer overflow), AutoLISP converts the integer to a real number.

amicalement, regards

[Lincoln Bauman]

Thanks for the replies, and the reminder that there is a maximum integer limit.
This also explains similar behavior with using the ATOI function.