bsnes/nall/string/replace.hpp

97 lines
3.5 KiB
C++

#ifdef NALL_STRING_INTERNAL_HPP
namespace nall {
template<unsigned Limit, bool Insensitive, bool Quoted>
auto _replace(string& self, rstring from, rstring to) -> string& {
if(Limit == 0 || from.size() == 0) return self;
signed size = self.size();
signed matches = 0;
signed quoted = 0;
//count matches first, so that we only need to reallocate memory once
//(recording matches would also require memory allocation, so this is not done)
{ const char* p = self.data();
for(signed n = 0; n <= size - (signed)from.size();) {
if(Quoted) { if(p[n] == '\"') { quoted ^= 1; n++; continue; } if(quoted) { n++; continue; } }
if(_compare<Insensitive>(p + n, size - n, from.data(), from.size())) { n++; continue; }
if(++matches >= Limit) break;
n += from.size();
}
}
if(matches == 0) return self;
//in-place overwrite
if(to.size() == from.size()) {
char* p = self.pointer();
for(signed n = 0, remaining = matches, quoted = 0; n <= size - (signed)from.size();) {
if(Quoted) { if(p[n] == '\"') { quoted ^= 1; n++; continue; } if(quoted) { n++; continue; } }
if(_compare<Insensitive>(p + n, size - n, from.data(), from.size())) { n++; continue; }
memory::copy(p + n, to.data(), to.size());
if(!--remaining) break;
n += from.size();
}
}
//left-to-right shrink
else if(to.size() < from.size()) {
char* p = self.pointer();
signed offset = 0;
signed base = 0;
for(signed n = 0, remaining = matches, quoted = 0; n <= size - (signed)from.size();) {
if(Quoted) { if(p[n] == '\"') { quoted ^= 1; n++; continue; } if(quoted) { n++; continue; } }
if(_compare<Insensitive>(p + n, size - n, from.data(), from.size())) { n++; continue; }
if(offset) memory::move(p + offset, p + base, n - base);
memory::copy(p + offset + (n - base), to.data(), to.size());
offset += (n - base) + to.size();
n += from.size();
base = n;
if(!--remaining) break;
}
memory::move(p + offset, p + base, size - base);
self.resize(size - matches * (from.size() - to.size()));
}
//right-to-left expand
else if(to.size() > from.size()) {
self.resize(size + matches * (to.size() - from.size()));
char* p = self.pointer();
signed offset = self.size();
signed base = size;
for(signed n = size, remaining = matches; n >= (signed)from.size();) { //quoted reused from parent scope since we are iterating backward
if(Quoted) { if(p[n] == '\"') { quoted ^= 1; n--; continue; } if(quoted) { n--; continue; } }
if(_compare<Insensitive>(p + n - from.size(), size - n + from.size(), from.data(), from.size())) { n--; continue; }
memory::move(p + offset - (base - n), p + base - (base - n), base - n);
memory::copy(p + offset - (base - n) - to.size(), to.data(), to.size());
offset -= (base - n) + to.size();
if(!--remaining) break;
n -= from.size();
base = n;
}
}
return self;
}
template<unsigned L> auto replace(string& self, rstring from, rstring to) -> string& { return _replace<L, 0, 0>(self, from, to); }
template<unsigned L> auto ireplace(string& self, rstring from, rstring to) -> string& { return _replace<L, 1, 0>(self, from, to); }
template<unsigned L> auto qreplace(string& self, rstring from, rstring to) -> string& { return _replace<L, 0, 1>(self, from, to); }
template<unsigned L> auto iqreplace(string& self, rstring from, rstring to) -> string& { return _replace<L, 1, 1>(self, from, to); }
};
#endif