Remove whitespace, convert case, in string except in quotes - c++

Question

I am using C++03 without Boost.
Suppose I have a string such as.. The day is "Mon day"
I want to process this to
THEDAYISMon day
That is, convert to upper case what is not in the quote, and remove whitespace that isn't in the quote.
The string may not contain quotes, but if it does, there will only be 2.
I tried using STL algorithms but I get stuck on how to remember if it's in a quote or not between elements.
Of course I can do it with good old for loops, but I was wondering if there is a fancy C++ way.
Thanks.
This is what I have using a for loop
while (getline(is, str))
{
// remove whitespace and convert case except in quotes
temp.clear();
bool bInQuote = false;
for (string::const_iterator it = str.begin(), end_it = str.end(); it != end_it; ++it)
{
char c = *it;
if (c == '\"')
{
bInQuote = (! bInQuote);
}
else
{
if (! ::isspace(c))
{
temp.push_back(bInQuote ? c : ::toupper(c));
}
}
}
swap(str, temp);

Answer 1

You can do something with STL algorithms like the following:
#include <iostream>
#include <string>
#include <algorithm>
#include <cctype>
using namespace std;
struct convert {
void operator()(char& c) { c = toupper((unsigned char)c); }
};
bool isSpace(char c)
{
return std::isspace(c);
}
int main() {
string input = "The day is \"Mon Day\" You know";
cout << "original string: " << input <<endl;
unsigned int firstQuote = input.find("\"");
unsigned int secondQuote = input.find_last_of("\"");
string firstPart="";
string secondPart="";
string quotePart="";
if (firstQuote != string::npos)
{
firstPart = input.substr(0,firstQuote);
if (secondQuote != string::npos)
{
secondPart = input.substr(secondQuote+1);
quotePart = input.substr(firstQuote+1, secondQuote-firstQuote-1);
//drop those quotes
}
std::for_each(firstPart.begin(), firstPart.end(), convert());
firstPart.erase(remove_if(firstPart.begin(),
firstPart.end(), isSpace),firstPart.end());
std::for_each(secondPart.begin(), secondPart.end(), convert());
secondPart.erase(remove_if(secondPart.begin(),
secondPart.end(), isSpace),secondPart.end());
input = firstPart + quotePart + secondPart;
}
else //does not contains quote
{
std::for_each(input.begin(), input.end(), convert());
input.erase(remove_if(input.begin(),
input.end(), isSpace),input.end());
}
cout << "transformed string: " << input << endl;
return 0;
}
It gave the following output:
original string: The day is "Mon Day" You know
transformed string: THEDAYISMon DayYOUKNOW
With the test case you have shown:
original string: The day is "Mon Day"
transformed string: THEDAYISMon Day

Answer 2

Just for laughs, use a custom iterator, std::copy and a std::back_insert_iterator, and an operator++ that knows to skip whitespace and set a flag on a quote character:
CustomStringIt& CustomStringIt::operator++ ()
{
if(index_<originalString_.size())
++index_;
if(!inQuotes_ && isspace(originalString_[index_]))
return ++(*this);
if('\"'==originalString_[index_])
{
inQuotes_ = !inQuotes_;
return ++(*this);
}
return *this;
}
char CustomStringIt::operator* () const
{
char c = originalString_[index_];
return inQuotes_ ? c : std::toupper(c) ;
}
Full code here.

Answer 3

You can use stringstream and getline with the \" character as the delimiter instead of newline.
Split your string into 3 cases: the part of the string before the first quote, the part in quotes, and the part after the second quote.
You would process the first and third parts before adding to your output, but add the second part without processing.
If your string contains no quotes, the entire string will be contained in the first part. The second and third parts will just be empty.
while (getline (is, str)) {
string processed;
stringstream line(str);
string beforeFirstQuote;
string inQuotes;
getline(line, beforeFirstQuote, '\"');
Process(beforeFirstQuote, processed);
getline(line, inQuotes, '\"');
processed += inQuotes;
getline(line, afterSecondQuote, '\"');
Process(afterFirstQuote, processed);
}
void Process(const string& input, string& output) {
for (string::const_iterator it = input.begin(), end_it = input.end(); it != end_it; ++it)
{
char c = *it;
if (! ::isspace(c))
{
output.push_back(::toupper(c));
}
}
}