Doriano Blengino ha scritto:
> Benoît Minisini ha scritto:
>
>>> Benoît Minisini ha scritto:
>>>
>>>
>>>>> Hi!
>>>>> There's minor bug.
>>>>> Overflow with concatenate operator causes wrong error message.
>>>>> You can reproduce the bug with this code:
>>>>>
>>>>> Dim ii As Integer
>>>>> Dim jj As Integer
>>>>>
>>>>> For ii = 9 To 0 Step -1
>>>>> jj&= ii<--- Wanted Integer got String instead.
>>>>> Next
>>>>>
>>>>> Gambas 3 rev 2879 @ Ubuntu 9.10 64bit
>>>>>
>>>>> Jussi
>>>>>
>>>>>
>>>> I'd like to know what you expected exactly from that code, and what you
>>>> think the error message should be!
>>>>
>>>> For information, the previous code is equivalent to:
>>>>
>>>> Dim ii As Integer
>>>> Dim jj As Integer
>>>>
>>>> For ii = 9 To 0 Step -1
>>>>
>>>> jj = CInt(CStr(jj)& CStr(ii))
>>>>
>>>> Next
>>>>
>>>> The error message comes from CInt(). When its argument cannot be
>>>> converted to an integer, it just says that there is a type mismatch (you
>>>> forgot to tell that) and that its argument is not an integer.
>>>>
>>>>
>>> I think that Jussi is right. Even the form you are using shows that the
>>> "&" operator is used with an integer to the left, and so, the "&" is
>>> meaningless. This is even more true with the C-style operator "&="
>>> which, by definition, must not cast the operand to the left.
>>>
Errata corrige.
It seems I must drive my car to better understand gambas... interesting...
Ok, now I understand the two code snippets above. The net result should
be an integer having value 9876543210. Apart from the fact that a simple
assignment does the same work, which leads me to think that Jussi wanted
something else, I am still not convinced about the casting (or, better,
conversion) while writing to variables.
I feel something weird in using an integer variable as if it was a
string, and the above snippet does that.
I wrote the same code and tried it - "wanted integer got string
instead". Then I traced the code, and discovered that the conversion
fails because an overflow, but the resulting error says something else
(I can understand why).
Well, what to say? I don't like the automatic conversion while writing,
but I am not sure. The more the language does things by its own, the
more you can get confused - anyway we don't want a stupid language you
must say everything to, right?. The routine I tested is:
PUBLIC SUB Form_Open()
DIM i, k AS Integer
k = 9876543210
k = 0
FOR i = 9 TO 0 STEP -1
' k &= i
PRINT "k="; k, "i="; i
k = CInt(CStr(k) & CStr(i))
NEXT
END
The first assignment "k = 9876543210" is silently accepted by both the
compiler and the interpreter, and is wrong. Apparently, gambas does two
different things while parsing a source and converting a string to an
integer at runtime; at last, I see two things that could be corrected
(incorrect constants and "not a string" instead of overflow).
Regards,
Doriano
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