How to make this string seperate using all the punctuation instead of spaces?-CodePudding

As in, the spaces do not separate the lines, only the punctuation does while also including the punctuation? This is my code:

#include <iostream>
#include <sstream>
#include <string>

using namespace std;

int main()
{
string s = "'Alice was beginning to get very tired of sitting by her sister on the bank, and of having nothing to do: once or twice she had peeped into the book her sister was reading, but it had no pictures or conversations in it, `and what is the use of a book, ' thought Alice `without pictures or conversation?'  So she was considering in her own mind(as well as she could, for the hot day made her feel very sleepyand stupid), whether the pleasure of making a daisy - chain would be worth the trouble of getting up and picking the daisies, when suddenly a White Rabbit with pink eyes ran close by her.There was nothing so very remarkable in that; nor did Alice think it so very much out of the way to hear the Rabbit say to itself, `Oh dear!Oh dear!I shall be late!' (when she thought it over afterwards, it occurred to her that she ought to have wondered at this, but at the time it all seemed quite natural); but when the Rabbit actually took a watch out of its waistcoat-pocket, and looked at it, and then hurried on, Alice started to her feet, for it flashed across her mind that she had never before seen a rabbit with either a waistcoat-pocket, or a watch to take out of it, and burning with curiosity, she ran across the field after it, and fortunately was just in time to see it pop down a large rabbit-hole under the hedge.'";
istringstream iss(s);

do
{
    string subs;
    iss >> subs;
    cout << "Substring: " << subs << endl;
} while (iss);
}

CodePudding user response：

Since many years in C we have support for splitting strings in respect to any kind of pattern.

It is called std::sregex_token_iterator. You can define the separators with very powerful regexes.

For example. If you want to split a string with separators ".,;:", then you can simply define a std::regex with std::regex separator{R"([\.,;:])"}. Then you can define the iterator with std::sregex_token_iterator(text.begin(), text.end(), separator, -1)

The nice thing is that many container have so called range constructors. They take 2 iterators and then copy everything given by the iterator into itself.

For example the std::vector, has such a constructor. And if you want to split the string and have the parts in a vector, then you could write:

std::vector stringParts(std::sregex_token_iterator(text.begin(), text.end(), separator, -1), {});

The {} at the end is the default constructor that is equal to the end constructor.

Please read here for further information.

CodePudding user response：

Go with Ranges!

As regards checking if a character is a punctuation mark, you can use ::ispunct.

As regards splitting when a char is a punctuation mark... you can split_when(::ispunct), which soulds just like plain English! Yeah, as simple as that: s | split_when(::ispunct) splits the string s at all the chars which are punctuation.

#include <cctype>
#include <iostream>
#include <string>
#include <range/v3/range/conversion.hpp>
#include <range/v3/view/split_when.hpp>

using namespace ranges;
using namespace ranges::views;

int main() {
    std::string s = "'Alice was beginning to get very tired of sitting by her sister on the bank, and of having nothing to do: once or twice she had peeped into the book her sister was reading, but it had no pictures or conversations in it, `and what is the use of a book, ' thought Alice `without pictures or conversation?'  So she was considering in her own mind(as well as she could, for the hot day made her feel very sleepyand stupid), whether the pleasure of making a daisy - chain would be worth the trouble of getting up and picking the daisies, when suddenly a White Rabbit with pink eyes ran close by her.There was nothing so very remarkable in that; nor did Alice think it so very much out of the way to hear the Rabbit say to itself, `Oh dear!Oh dear!I shall be late!' (when she thought it over afterwards, it occurred to her that she ought to have wondered at this, but at the time it all seemed quite natural); but when the Rabbit actually took a watch out of its waistcoat-pocket, and looked at it, and then hurried on, Alice started to her feet, for it flashed across her mind that she had never before seen a rabbit with either a waistcoat-pocket, or a watch to take out of it, and burning with curiosity, she ran across the field after it, and fortunately was just in time to see it pop down a large rabbit-hole under the hedge.'";

    for (auto i : s | split_when(::ispunct)) {
        std::cout << "Substring: " << (i | to<std::string>) << std::endl;
    }
}

to<std::string> is to convert each view obtained from split_when into an actual std::string. (You can try removing | to<std::string> and you'll see what that means.)