Subfield with consecutive delimiters - a bug?

[#1]

If I have a string with the occasional multiple delimiters between data, Subfield extracts the delimiter and not the expected data.

Example:

=subfield('abcdef    MyData zzzz', ' ' , 2)

I expect the above to return 'MyData', but it returns ' ' (a space)

I could use the following very ugly statement, but I'm not thrilled about doing so, especially since this needs to be done during a load.

=Subfield(TRIM( MID('abcdef    MyData zzzz',INDEX('abcdef    MyData zzzz',' ',1)) ),' ',1)

Based on my experience with many other languages, I expected the subfield to eat the extra consecutive  delimiters, but that is not happening.

Q1) is this the expected Subfield behavior or a bug?

Q2) Does anyone have a better method than my above expression?

TIA,

John

QV 11.20, SR4

[engishfaque]

Dear John,

Neither it's bug nor it's expression issue.

It's actually happening due to, you are using double space in expression.

Correct:

=subfield('abcdef MyData zzzz', ' ' , 2)

Your script with spaces:

=subfield('abcdef    MyData zzzz', ' ' , 2)

Kind regards,

Ishfaque Ahmed

[robert_mika]

You are right Colin.

Thanks for the explanation

[MarcoWedel]

Hi,

as John stated it's human entered data, I tried to extend your solution to work with any number of spaces (for John's users with itchy fingers 😉

tabStrings:
LOAD *,
    RecNo() as ID
Inline [
string
abcdef                                                    MyData          zzzz
abcdef    MyData zzzz
abcdef    MyData zzzz
abcdef  MyData zzzz
abcdef  MyData zzzz
abcdef MyData zzzz
abcdef    MyData  zzzz
abcdef    MyData  zzzz
abcdef  MyData  zzzz
abcdef  MyData  zzzz
abcdef MyData  zzzz
abcdef    MyData  zzzz
abcdef    MyData  zzzz
abcdef  MyData  zzzz
abcdef  MyData  zzzz
abcdef MyData  zzzz
abcdef    MyData    zzzz
abcdef    MyData    zzzz
abcdef  MyData    zzzz
abcdef  MyData    zzzz
abcdef MyData    zzzz
abcdef    MyData    zzzz
abcdef    MyData    zzzz
abcdef  MyData    zzzz
abcdef  MyData    zzzz
abcdef MyData    zzzz
aa bb cc
aa  bb cc
aa bb  cc
aaa bb  cc
aaa  bb cc
];

SpaceMap:
MAPPING LOAD Repeat(' ',IterNo()+1) , ' '
While IterNo()<MaxSpaces;
LOAD Max(IterNo) as MaxSpaces;
LOAD IterNo() as IterNo
Resident tabStrings
While Index(string, Repeat(' ',IterNo())) or IterNo()=1;

Left Join (tabStrings)
LOAD Distinct
  string,
  SubField(MapSubString('SpaceMap', string),' ',2) as SubString2
Resident tabStrings;

hope this helps

regards

Marco

[rwunderlich]

Clever Marco. But wouldn't you agree that

  AutoGenerate 9999

is easier to read and faster?

-Rob

[MarcoWedel]

Yes, indeed. Good point

Maybe it just proves that one could create a generic solution without assumptions,

even if it's not very practical for a productive solution ...

regards

Marco

[rwunderlich]

I like your thinking.

-Rob

[#8]

Colin,

I do have to back of somewhat on my sweeping statement about eating delimiters.

I would like and expect a split / subfield command to treat consecutive 'space' delimiters as one delimiter, but I do not want the command to treat consecutive non-space delimiters (such as commas) as one delimiter.

JLR

[#9]

Peter,

Java, PHP, C, Perl, Python, etc ... all have a variation on the following:

    s.split(" +");

But they use a regular expression to split the string, which is not available to us in QV.

[#10]

re: Excel's trim - I did not know that. strange.  Not sure I like that. 
QV's trim functions as I expect - trim leading / trailing spaces and does nothing to the body of the string.

[#11]

Interesting - yet another way to fix the issue.  Thanks.

(And Rob, thanks for your "Cookbook".  It has been helpful).