Re: [Jscheme-user] 081 ?bug?

[Timothy J H. <tjh...@br...>]

This brings us back to an early thread from June of 2004 ...
in which we decided to disallow Java octal notation in (string->number 
x)
invocations, but to allow it in JScheme code to ease the interaction
with Java ...

On Nov 18, 2004, at 6:25 PM, Robert J. Bobrow wrote:

>  This lef to my trying the following test:
>  > (- 0777 777)
>  -266
>

 > (- (string->number "0777") 777)
   0

 > (.getClass (read))
081
class jsint.Symbol

>  Is it required that numbers starting with 0 be treated as octal?
>  --Rusty
>
>
>
>
.

The idea was that JScheme literals should be the same as Java literals
whenever possible to enhance the transparency of the javadot interface.
In standard Scheme code, octal is not very important because you rarely
deal with 32 or 64 bit integers.  Java is a different story, e.g. 
converting from
long bits to double its nice to have a hex representation of 
integers....

---Tim---

>
>
> Begin forwarded message:
>
>> From: Ken Anderson <kan...@bb...>
>> Date: June 7, 2004 10:24:02 AM EDT
>> To: Timothy John Hickey <tim...@ma...>
>> Cc: JScheme Developers <jsc...@li...>
>> Subject: Re: [Jscheme-devel] string->number
>>
>> So the remaining issue is what should (string->number "08") return.  
>> It currently returns #f. i was hoping it would return 8.
>>
>> At 07:27 PM 6/6/2004 -0400, Timothy John Hickey wrote:
>>> I've modified string->number so that in the base 10 case it allows 
>>> leading zeroes...
>>> The following Unit tests all pass in the current version of 
>>> JScheme...
>>>
>>>  "06/06/2004" ;; literal syntax, TJH
>>>
>>>  ;; Default literal syntax is for Java literals,
>>>
>>>  ;; but string->number will treat leading zeroes as decimal if base 
>>> 10 is specified
>>>
>>>  (equal? (.getClass '081) jsint.Symbol.class)
>>>
>>>  (equal? (.getClass '0123Dig) jsint.Symbol.class)
>>>
>>>  (equal? (.getClass '0123) java.lang.Integer.class)
>>>
>>>  (equal? (string->number "081" 10) 81)
>>>
>>>  (equal? (string->number "010") 10)
>>>
>>>  (equal? (string->number "010" 8) 8)
>>>
>>>  (equal? (tryCatch (string->number "081" 8) (lambda(e) 'error)) 
>>> 'error)
>>>
>>>  (equal? (string->number "08") #f)
>>>
>>>  (equal? (string->number "08" 10) 8)
>>>
>>>  (equal? (string->number "10") 8)
>>>
>>>  (equal? (string->number "10" 10) 10)
>>>
>>> The implementation of string->number in the base 10 case is
>>>
>>>>  public static Object schemeStringToNumber(String tok, int rdx) {
>>>>    try { return U.toNum(Long.parseLong(tok, rdx)); }
>>>>     catch (NumberFormatException e) {
>>>>         try {
>>>>             if (rdx!=10)
>>>>                 return U.FALSE;
>>>>             else return new Double(tok); }
>>>>         catch (NumberFormatException e2)
>>>>             { return U.FALSE; }
>>>>     }
>>>>  }
>>>
>>> ---Tim---
>>>
>>>
>>>