Test if integer?

[chavlji]

How to test if certain string can be converted to integer. That it is constructed only of numbers...

I need it for itoa.

[Lee Mac]

Perhaps?

 

(defun numtxt  (str)
 (vl-every '(lambda (x) (<= 48 x 57)) (vl-string->list str)))

 

Returns T or nil

[lpseifert]

after dissection, very clever Lee...

[ASMI]

Do you mean:

 

Command: (atoi "bla bla bla")
0

?

 

(defun atoi2(str)
 (if(distof str)(atoi str))
 ); end of atoi2

 

Command: (atoi2 "bla bla bla")
nil

 

Command: (atoi2 "8")
8

 

Command: (atoi2 "87.345123453")
87

[Lee Mac]

Cheers Larry

[chavlji]

Thanks!

 

Found in help later that atoi returns 0 if invalid string Although your solutions are great.

[Lee Mac]

But I suppose its good to know if it is an invalid string as opposed to a user entering 0

 

Anything else, just ask

[David Bethel]

Sometimes 0 would be a valid return...

 

On older way:

 

[b][color=BLACK]([/color][/b]defun testistr [b][color=FUCHSIA]([/color][/b]s / tmp[b][color=FUCHSIA])[/color][/b]
 [b][color=FUCHSIA]([/color][/b]setq tmp [color=#2f4f4f]""[/color][b][color=FUCHSIA])[/color][/b]
 [b][color=FUCHSIA]([/color][/b]repeat [b][color=NAVY]([/color][/b]strlen s[b][color=NAVY])[/color][/b]
         [b][color=NAVY]([/color][/b]setq tmp [b][color=MAROON]([/color][/b]strcat tmp [color=#2f4f4f]"#"[/color][b][color=MAROON])[/color][/b][b][color=NAVY])[/color][/b][b][color=FUCHSIA])[/color][/b]
 [b][color=FUCHSIA]([/color][/b]wcmatch s tmp[b][color=FUCHSIA])[/color][/b][b][color=BLACK])[/color][/b]

-David

[Lee Mac]

Sometimes 0 would be a valid return...

 

On older way:

 

[b][color=BLACK]([/color][/b]defun testistr [b][color=FUCHSIA]([/color][/b]s / tmp[b][color=FUCHSIA])[/color][/b]
 [b][color=FUCHSIA]([/color][/b]setq tmp [color=#2f4f4f]""[/color][b][color=FUCHSIA])[/color][/b]
 [b][color=FUCHSIA]([/color][/b]repeat [b][color=NAVY]([/color][/b]strlen s[b][color=NAVY])[/color][/b]
         [b][color=NAVY]([/color][/b]setq tmp [b][color=MAROON]([/color][/b]strcat tmp [color=#2f4f4f]"#"[/color][b][color=MAROON])[/color][/b][b][color=NAVY])[/color][/b][b][color=FUCHSIA])[/color][/b]
 [b][color=FUCHSIA]([/color][/b]wcmatch s tmp[b][color=FUCHSIA])[/color][/b][b][color=BLACK])[/color][/b]

-David

 

 

Great idea David - love it. So many ways to accomplish the same thing

[CAB]

You might make use of this?

(vl-some '(lambda (x) (< 47 x 50)) (vl-string->list "abd1ef"))

[Lee Mac]

(defun numtxt  (str)
 (vl-every '(lambda (x) (<= 48 x 57)) (vl-string->list str)))

Returns T or nil

 

CAB, would you say that vl-some should be used then, instead of vl-every?

[CAB]

Sorry, jumping in and out of this thread over several days, I forgot what was & wasn't posted.

This morning I revisited the entire thread & see the Lee had already posted this test. I also

see that the OP said the string was comprised of numbers only. My post like Lee's is just a test

to confirm that there is at lease one number embedded in the string. Not a solution for the OP.

 

I use this to convert a number from a string. (Must be a valid number)

 

  ;;+++++++++++++++++++++++++++++++
 ;;  convert the text to a number or nil
 ;;+++++++++++++++++++++++++++++++
 (defun txt2num (txt / num)
   (or (setq num (distof txt 5))
       (setq num (distof txt 2))
       (setq num (distof txt 1))
       (setq num (distof txt 4))
       (setq num (distof txt 3))
   )
   num
 )

 

Returns nil if not a valid number.

[Se7en]

CAB,

You can avoid the allocation and destruction of a variable inside your support procedure by using a COND.

 

(defun txt2num ( txt )
 (cond
   ((distof txt 5))
   ((distof txt 2))
   ((distof txt 1))
   ((distof txt 4))
   ((distof txt 3))
 ) 
)

[David Bethel]

Doesn't distof work with 'REALs. I think the OP was for INTegers. as he wanted to use ITOA -David

[Se7en]

I dunno, i didn't read the thread i just read the last post. ...wait a min? DISTOF works with strings and converts them to reals. ITOA converts an int to a string. Did you mean ATOI?

[Se7en]

It looks like the problem has been answered several times now so were good.

[ASMI]

Easy way:

 

(defun ITest(Str)
 (=(distof Str 2)(atoi Str))
 )

 

Testing:

 

_$ (ITest "5")
T
_$ (ITest "-50")
T
_$ (ITest "5.000008")
nil
_$ (ITest "5blablabla")
nil
_$ (ITest "0")
T