exercism-solutions/cpp/word-count/word_count.cpp

73 lines
1.4 KiB
C++

#include "word_count.h"
#include <algorithm>
namespace word_count {
using namespace std;
Words words(const string &str, const locale &loc)
{
Words result;
enum {
InsideWord,
OutsideWord
} state(OutsideWord);
string::const_iterator begin, end, i;
i = begin = end = str.begin();
for (; i != str.end(); ++i) {
bool is_alpha_or_digit = isalpha(*i, loc) || isdigit(*i, loc);
bool is_word_char = is_alpha_or_digit || *i == '\'';
switch (state) {
case OutsideWord:
if (is_alpha_or_digit) {
state = InsideWord;
begin = i;
end = next(i);
}
break;
case InsideWord:
if (is_alpha_or_digit) {
end = next(i);
}
if (!is_word_char || next(i) == str.end()) {
state = OutsideWord;
if (begin != end) {
string word;
word.reserve(distance(begin, end));
transform(begin, end, back_inserter(word),
[=](char c){return tolower(c, loc);});
result[word]++;
}
}
break;
}
}
return result;
}
}