ticky problem

[onkar]

I am in a situation wherein I want to process input line by line .
Each line contians numbers.

sample input :

1 2 3 4 5
5 6 7
1
2 3 4 56 7 8
0
my program must take 1 2 3 4 5 first -process it -5 6 7 -process
it and likewise. How can i do it without considering each line as a
string and seperating out numbers ? Can I directly use some kind of
loop ? and how is the loop going to terminate ?

[Juha Nieminen]

onkar wrote:

I am in a situation wherein I want to process input line by line .
Each line contians numbers.

sample input :

1 2 3 4 5
5 6 7
1
2 3 4 56 7 8
0
my program must take 1 2 3 4 5 first -process it -5 6 7 -process
it and likewise. How can i do it without considering each line as a
string and seperating out numbers ? Can I directly use some kind of
loop ? and how is the loop going to terminate ?

The easiest way is probably read the input line by line with
getline(), create an istringstream from that line, and then read the
values with >until there are no more.

[Pete Becker]

On 2008-05-31 11:24:46 -0400, onkar <on*******@gmail.comsaid:

I am in a situation wherein I want to process input line by line .
Each line contians numbers.

sample input :

1 2 3 4 5
5 6 7
1
2 3 4 56 7 8
0
my program must take 1 2 3 4 5 first -process it -5 6 7 -process
it and likewise. How can i do it without considering each line as a
string and seperating out numbers ?

That's the usual way to do it. Why don't you want to do it this way?

Can I directly use some kind of
loop ? and how is the loop going to terminate ?

Sure. You can read a character at a time, parse the numbers and
separators, and start processing the line when you hit a newline.
That's a lot more work than the usual approach.

--
Pete
Roundhouse Consulting, Ltd. (www.versatilecoding.com) Author of "The
Standard C++ Library Extensions: a Tutorial and Reference
(www.petebecker.com/tr1book)

[Chris Gordon-Smith]

onkar wrote:

I am in a situation wherein I want to process input line by line .
Each line contians numbers.

sample input :

1 2 3 4 5
5 6 7
1
2 3 4 56 7 8
0
my program must take 1 2 3 4 5 first -process it -5 6 7 -process
it and likewise. How can i do it without considering each line as a
string and seperating out numbers ? Can I directly use some kind of
loop ? and how is the loop going to terminate ?

I recently had to do something like this. I decided to treat the input file
as a set of logical records, rather than as a set of lines. A record can
span multiple lines. Each record is terminated by a semicolon.

I have a loop that uses the >operator to read tokens into a string
variable (called Token!). Each token string is then pushed into a list of
strings (list<std:stringfor further processing. A record is complete when
I find a token that is (or ends with) a semicolon.

The need for a semicolon terminator is necessary to give me the flexibility
to have records spanning multiple lines.

If you don't need this flexibility then the approach posted by juha Nieminem
looks sensible to me.

Chris Gordon-Smith
www.simsoup.info

[Daniel T.]

onkar <on*******@gmail.comwrote:

I am in a situation wherein I want to process input line by line .
Each line contians numbers.

sample input :

1 2 3 4 5
5 6 7
1
2 3 4 56 7 8
0
my program must take 1 2 3 4 5 first -process it -5 6 7 -process
it and likewise. How can i do it without considering each line as a
string and seperating out numbers ? Can I directly use some kind of
loop ? and how is the loop going to terminate ?

void process( const vector<int>& numbers );

void foo( istream& is )
{
string str;
while ( getline( is, str ) )
{
istringstream iss( str );
vector<intnumbers;
copy( istream_iterator<int>( iss ), istream_iterator<int>(),
back_inserter( numbers ) );
process( numbers );
}
}

What's wrong with the above?

[=?UTF-8?B?RXJpayBXaWtzdHLDtm0=?=]

On 2008-05-31 18:58, Chris Gordon-Smith wrote:

onkar wrote:

>I am in a situation wherein I want to process input line by line .
Each line contians numbers.

sample input :

1 2 3 4 5
5 6 7
1
2 3 4 56 7 8
0
my program must take 1 2 3 4 5 first -process it -5 6 7 -process
it and likewise. How can i do it without considering each line as a
string and seperating out numbers ? Can I directly use some kind of
loop ? and how is the loop going to terminate ?

I recently had to do something like this. I decided to treat the input file
as a set of logical records, rather than as a set of lines. A record can
span multiple lines. Each record is terminated by a semicolon.

I have a loop that uses the >operator to read tokens into a string
variable (called Token!). Each token string is then pushed into a list of
strings (list<std:stringfor further processing. A record is complete when
I find a token that is (or ends with) a semicolon.

Could you not just have used getline(file, string, ';') instead of doing
multiple >operations?

--
Erik Wikström

[Chris Gordon-Smith]

Erik Wikström wrote:

On 2008-05-31 18:58, Chris Gordon-Smith wrote:

>onkar wrote:

>>I am in a situation wherein I want to process input line by line .
Each line contians numbers.

sample input :

1 2 3 4 5
5 6 7
1
2 3 4 56 7 8
0
my program must take 1 2 3 4 5 first -process it -5 6 7 -process
it and likewise. How can i do it without considering each line as a
string and seperating out numbers ? Can I directly use some kind of
loop ? and how is the loop going to terminate ?

I recently had to do something like this. I decided to treat the input
file as a set of logical records, rather than as a set of lines. A record
can span multiple lines. Each record is terminated by a semicolon.

I have a loop that uses the >operator to read tokens into a string
variable (called Token!). Each token string is then pushed into a list of
strings (list<std:stringfor further processing. A record is complete
when I find a token that is (or ends with) a semicolon.

Could you not just have used getline(file, string, ';') instead of doing
multiple >operations?

Possibly, although I would have still had to separate out the tokens.
getline on its own would just give me a single string without separating
out tokens.

(If I had known about the alternate version of getline you quote I probably
would indeed have used it!)

Chris Gordon-Smith
www.simsoup.info

[El-Hassan Wanas]

On May 31, 8:26*pm, Chris Gordon-Smith <[e-mail]>
wrote:

Erik Wikström wrote:

On 2008-05-31 18:58, Chris Gordon-Smith wrote:

onkar wrote:

>I am in a situation wherein I want to process *input line by line .
Each line contians numbers.

>sample input :

>1 2 3 4 5
5 6 7
1
2 3 4 56 7 8
0

>my program must take 1 2 3 4 5 first -process it -5 6 7 -process
it and likewise. How can i do it without considering each line as a
string and seperating out numbers ? Can I directly use some kind of
loop ? and how is the loop going to terminate ?

I recently had to do something like this. I decided to treat the input
file as a set of logical records, rather than as a set of lines. A record
can span multiple lines. Each record is terminated by a semicolon.

I have a loop that uses the >operator to read tokens into a string
variable (called Token!). Each token string is then pushed into a list of
strings (list<std:stringfor further processing. A record is complete
when I find a token that is (or ends with) a semicolon.

Could you not just have used getline(file, string, ';') instead of doing
multiple >operations?

Possibly, although I would have still had to separate out the tokens.
getline on its own would just give me a single string without separating
out tokens.

(If I had known about the alternate version of getline you quote I probably
would indeed have used it!)

Chris Gordon-Smithwww.simsoup.info

Can't you just:

std::vector<intnumbers(0);
std::vector<std::vector <int numberGroups(0);
while(cin){
while (cin.peek() != '\n'){
int number;
cin >number;
numbers.push_back(number);
}
numberGroups.push_back(numbers);
//yourfunctionhere e.g. weirdfunction(numberGroups);
numbers.clear();
}

Regards,

Wanas
http://programmingden.blogspot.com