Nix/src/libexpr/search-path.cc

56 lines
1.2 KiB
C++

#include "search-path.hh"
namespace nix {
std::optional<std::string_view> SearchPath::Prefix::suffixIfPotentialMatch(
std::string_view path) const
{
auto n = s.size();
/* Non-empty prefix and suffix must be separated by a /, or the
prefix is not a valid path prefix. */
bool needSeparator = n > 0 && n < path.size();
if (needSeparator && path[n] != '/') {
return std::nullopt;
}
/* Prefix must be prefix of this path. */
if (path.compare(0, n, s) != 0) {
return std::nullopt;
}
/* Skip next path separator. */
return {
path.substr(needSeparator ? n + 1 : n)
};
}
SearchPath::Elem SearchPath::Elem::parse(std::string_view rawElem)
{
size_t pos = rawElem.find('=');
return SearchPath::Elem {
.prefix = Prefix {
.s = pos == std::string::npos
? std::string { "" }
: std::string { rawElem.substr(0, pos) },
},
.path = Path {
.s = std::string { rawElem.substr(pos + 1) },
},
};
}
SearchPath parseSearchPath(const Strings & rawElems)
{
SearchPath res;
for (auto & rawElem : rawElems)
res.elements.emplace_back(SearchPath::Elem::parse(rawElem));
return res;
}
}