parse comma delimited text string

[electrixnow]

in MS VC++ Express I need to know how to get from one comma delimited
text string to many strings.

from this:

main_string = "onE,Two,Th ree , fouR,five, six "

to these:

string1 = "one"
string2 = "two"
string3 = "three"
string4 = "four"
string5 = "five"
string6 = "six"

the white space needs to be removed and the case needs to be all upper
or lower.
The result needs to be strings and not pointers or addresses in memory
so I can test:

string test = "three";

if (three == "three")

some getlines will only have two strings some may have up to 10
Please help with examples, you input with exact syntax is greatly
appreciated

I have been struggling with not using pointers but every time I end up
using them.

Thanks in advance

[Daniel T.]

In article <44************ @individual.net >,
"Sumit Rajan" <su*********@gm ail.com> wrote:

"Sumit Rajan" <su*********@gm ail.com> wrote in message
news:44******** ****@individual .net...

void trim(std::strin g& str)
{
std::string::si ze_type idx = str.find_first_ not_of(' ');
if (idx != std::string::np os) {
str.erase(0, idx);
}
idx = str.find_last_n ot_of(' ');
if (idx != std::string::np os) {
str.erase(idx+1 , str.size()-1);
}
}

Sorry, this function has a bug. May be simplest to use an std::istringstr eam
as you will see in Alf's post.

What bug do you see? The only bug I can find is that if 'str' is nothing
but spaces then the function doesn't do anything.

--
Magic depends on tradition and belief. It does not welcome observation,
nor does it profit by experiment. On the other hand, science is based
on experience; it is open to correction by observation and experiment.

[Shaun]

Since your using VC++ express, are you using standard C++ or C++/CLI?
I ask becasue if your using the managed String classes, you can very
easily do what you wish as follows:

System::String^ s = "1,2,3,4,5" ;
cli::array<Syst em::String^>^ s2 = s->Split(',');
// now use s2[0]...s2[s2->Length] as needed.

If using standard C++, then the suggestions already provided by the
other posters are worth considering.

[Roland Pibinger]

On Tue, 07 Feb 2006 11:05:54 GMT, al***@start.no (Alf P. Steinbach)
wrote:

StringVector stringsFrom( std::string s )
{
std::replace( s.begin(), s.end(), ',', ' ' );
std::istringstr eam stream( s );
StringVector result;
for( ;; )
{
std::string word;
if( !( stream >> word ) ) { break; }
result.push_bac k( uppercase( word ) );
}
return result;
}

Alternative string tokenizers can be found here:
http://groups.google.com/group/comp....8f07f527?hl=en

Best regards,
Roland Pibinger

[Dietmar Kuehl]

electrixnow wrote:

the white space needs to be removed and the case needs to be all upper
or lower.

My favorite approach would be to use a filtering stream buffer
to do the clean-up and use normal string input functions otherwise:

#include <iostream>
#include <streambuf>
#include <algorithm>
#include <iterator>
#include <string>
#include <vector>
#include <stdlib.h>

char clean(char i)
{
return i == ','? ' '
: std::tolower(st atic_cast<unsig ned char>(i));
}

struct cleanbuf:
std::streambuf
{
enum { s_size = 1024 };
cleanbuf(std::s treambuf* sbuf): m_sbuf(sbuf) {}
int underflow()
{
std::streamsize size = m_sbuf->sgetn(m_buf, s_size);
setg(m_buf, m_buf, m_buf + size);
std::transform( m_buf + 0, m_buf + size, m_buf, clean);
return gptr() == egptr()
? std::char_trait s<char>::eof() : *gptr();
}
private:
std::streambuf* m_sbuf;
char m_buf[s_size];
};

int main()
{
cleanbuf sbuf(std::cin.r dbuf());
std::istream in(&sbuf);
std::vector<std ::string> strs(
(std::istream_i terator<std::st ring>(in)),
(std::istream_i terator<std::st ring>()));
std::copy(strs. begin(), strs.end(),
std::ostream_it erator<std::str ing>(std::cout, "\n"));
}
~
--
<mailto:di***** ******@yahoo.co m> <http://www.dietmar-kuehl.de/>
<http://www.eai-systems.com> - Efficient Artificial Intelligence

[Sumit Rajan]

"Daniel T." <po********@ear thlink.net> wrote in message
news:po******** *************** *******@news.ea st.earthlink.ne t...

What bug do you see? The only bug I can find is that if 'str' is nothing
but spaces then the function doesn't do anything.

Precisely. My other post on this thread takes care of it.

Regards,
Sumit.
--
Sumit Rajan <su****@msdc.hc ltech.com>

[Daniel T.]

In article <44************ @individual.net >,
"Sumit Rajan" <su*********@gm ail.com> wrote:

"Daniel T." <po********@ear thlink.net> wrote in message
news:po******** *************** *******@news.ea st.earthlink.ne t...

What bug do you see? The only bug I can find is that if 'str' is nothing
but spaces then the function doesn't do anything.

Precisely. My other post on this thread takes care of it.

I think your other post was more complicated than necessary...

str.erase( 0, str.find_first_ not_of( whitespace ) );

Takes care if it without the extra conditionals/loops.

--
Magic depends on tradition and belief. It does not welcome observation,
nor does it profit by experiment. On the other hand, science is based
on experience; it is open to correction by observation and experiment.

[Daniel T.]

In article <44************ @individual.net >,
Dietmar Kuehl <di***********@ yahoo.com> wrote:

electrixnow wrote:

the white space needs to be removed and the case needs to be all upper
or lower.
My favorite approach would be to use a filtering stream buffer
to do the clean-up and use normal string input functions otherwise:

Unfortunately, your code doesn't compile on my system. I had to change
the vector<string> c_tor call to:

vector<string> strs;
copy ( istream_iterato r<string>(in), istream_iterato r<string>(),
back_inserter(s trs) );

Also, your code only works for the simple case, where there is no
whitespace *within* a string delimited by commas. How would you change
it to account for the more complicated case?

The nice thing about your code is that it does everything in a single
pass whereas the code I presented to date requires two passes (one to
call tolower, and a second to remove the commas.) It would be a simple
change to make mine one pass as well...

template < typename Out >
void fn( string str, Out it )
{
transform( str.begin(), str.end(), str.begin(), clean );
// the above uses your 'clean' function.
stringstream ss( str );
copy( istream_iterato r<string>( ss ), istream_iterato r<string>(),
it );
}

This seems much more straight forward and needs fewer lines of code.

I must say that every contribution so far has shed new light on the
problem for me and caused me to improve my code in some way. IMHO, this
is usenet at its best.
#include <iostream>
#include <streambuf>
#include <algorithm>
#include <iterator>
#include <string>
#include <vector>
#include <stdlib.h>

char clean(char i)
{
return i == ','? ' '
: std::tolower(st atic_cast<unsig ned char>(i));
}

struct cleanbuf:
std::streambuf
{
enum { s_size = 1024 };
cleanbuf(std::s treambuf* sbuf): m_sbuf(sbuf) {}
int underflow()
{
std::streamsize size = m_sbuf->sgetn(m_buf, s_size);
setg(m_buf, m_buf, m_buf + size);
std::transform( m_buf + 0, m_buf + size, m_buf, clean);
return gptr() == egptr()
? std::char_trait s<char>::eof() : *gptr();
}
private:
std::streambuf* m_sbuf;
char m_buf[s_size];
};

int main()
{
cleanbuf sbuf(std::cin.r dbuf());
std::istream in(&sbuf);
std::vector<std ::string> strs(
(std::istream_i terator<std::st ring>(in)),
(std::istream_i terator<std::st ring>()));
std::copy(strs. begin(), strs.end(),
std::ostream_it erator<std::str ing>(std::cout, "\n"));
}
~

--
Magic depends on tradition and belief. It does not welcome observation,
nor does it profit by experiment. On the other hand, science is based
on experience; it is open to correction by observation and experiment.

[Sumit Rajan]

"Daniel T." <po********@ear thlink.net> wrote in message
news:po******** *************** *******@news.ea st.earthlink.ne t...

I think your other post was more complicated than necessary...

str.erase( 0, str.find_first_ not_of( whitespace ) );

Takes care if it without the extra conditionals/loops.

True. This one is far more reader-friendly.

Regards,
Sumit.
--
Sumit Rajan <su****@msdc.hc ltech.com>

[Dietmar Kuehl]

Daniel T. wrote:

Unfortunately, your code doesn't compile on my system. I had to change
the vector<string> c_tor call to:

vector<string> strs;
copy ( istream_iterato r<string>(in), istream_iterato r<string>(),
back_inserter(s trs) );
In this case your compiler or the standard library implementation is
broken: the standard container classes are defined to accept pairs of
input iterators as constructor arguments.
Also, your code only works for the simple case, where there is no
whitespace *within* a string delimited by commas. How would you change
it to account for the more complicated case?
This is a rather different specification which, in particular, does
not yet account for whitespace at the beginning or the end of the
string: is this whitespace to be removed or not? Since commas work
as true delimiters here, I assume it is to be included. I this case
I would [temporarily] 'imbue()' a 'std::ctype<cha r>' facet which
only considers comma and possibly newline (if this is also considered
a separator). The extractor functions use whitespaces as field
separators for strings. If the case adjustment is still necessary,
I would use the modified facet in combination with the filtering
stream buffer.
This seems much more straight forward and needs fewer lines of code.
Injecting existing filtering stream buffers into the processing is
pretty straight forward. Of course, writing them is not necessarily
so but it is not that hard either. The real advantage I see in the
filtering stream buffer over your code is that it encapsulates the
complete solution, especially if it is also equipped with a simple
input stream which automatically maintains the stream buffer.
I must say that every contribution so far has shed new light on the
problem for me and caused me to improve my code in some way.

This was my intention of posting the code...
--
<mailto:di***** ******@yahoo.co m> <http://www.dietmar-kuehl.de/>
<http://www.eai-systems.com> - Efficient Artificial Intelligence

[Dietmar Kuehl]

Daniel T. wrote:

int (*lower)(int) = &tolower;
transform( str.begin(), str.end(), str.begin(), lower );

Note that this does *NOT* work! The argument to 'std::tolower() '
has to be an *unsigned* value. However, on platforms where 'char'
is signed, the argument could expand to a negative value! In
portable code, the only valid call to 'std::tolower(i nt)' with a
'char' looks like this:

std::tolower(st atic_cast<unsig ned char>(c));

The only possible variation is how the 'char' is first cast to
an 'unsigned char'.
--
<mailto:di***** ******@yahoo.co m> <http://www.dietmar-kuehl.de/>
<http://www.eai-systems.com> - Efficient Artificial Intelligence