CODEWITHSUNDEEP
c++stringparsingstream
kbirk
kbirk

Reputation: 4022

stringstream >> inconsistent '\n' delimiter behaviour

I have the following function to read in a stream of text and chop it up into a vector of a given type:

template<class Type>
void parse_string(std::vector<Type> &type_vector, char *string) 
{
    std::stringstream stream(string);
    while (stream.good()) 
    {
        Type t;
        stream >> t;
        type_vector.push_back(t);
    }
}

The char *string parameter is a chunk of text representing either floating point numbers or strings each separated with either ' ' or '\n'.

Now my issue is that when given a std::vector<float> type_vector, the parse_string function will separate by both the ' ' or '\n' delimiters. For example for:

0.01 0.02 0.03 0.04
0.05 0.06 0.07 0.08

it will read '0.04' and '0.05' as separate tokens. This is what I want!

However if given a std::vector<std::string> type_vector, the parse_string will only separate by ' '. Therefore if my text is as follows:

root_joint left_hip left_knee left_ankle
left_foot right_hip right_knee right_ankle

it will read 'left_ankleleft_foot' as a single token. It doesn't seem to take into account that there is a '\n' between 'left_ankle' and 'left_foot'.

What is causing this?

EDIT:

The exact char* arguments as seen in the debugger are as follows:

0.01 0.02 0.03 0.040.05 0.06 0.07 0.08

root_joint left_hip left_knee left_ankleleft_foot right_hip right_knee right_ankle

So it seems to completely ignore the '\n' from the file...

EDIT2:

Okay I figured out what I was doing wrong. As many of you pointed out, it had nothing to do with stringstream.

My parser required a std::vector copy of the file. In the process of reading the file into a string and converting it into the vector, I used the getLine(std::ifstream, std::string) function, which as you can guess, strips the '\n' newline character.

Upvotes: 3

Views: 823

Answers (1)

Christopher Oezbek
Christopher Oezbek

Reputation: 26353

You are reading the string incorrectly, so that \n is discarded. \n should lead to a split.

Upvotes: 1

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