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#pragma once
///@file
#include "error.hh"
#include "types.hh"
#include <vector>
namespace nix {
/**
* Tree formatting.
*/
constexpr char treeConn[] = "├───";
constexpr char treeLast[] = "└───";
constexpr char treeLine[] = "│ ";
constexpr char treeNull[] = " ";
/**
* Convert a list of strings to a null-terminated vector of `char
* *`s. The result must not be accessed beyond the lifetime of the
* list of strings.
*/
std::vector<char *> stringsToCharPtrs(const Strings & ss);
MakeError(FormatError, Error);
/**
* String tokenizer.
*/
template<class C> C tokenizeString(std::string_view s, std::string_view separators = " \t\n\r");
/**
* Concatenate the given strings with a separator between the
* elements.
*/
template<class C>
std::string concatStringsSep(const std::string_view sep, const C & ss)
{
size_t size = 0;
// need a cast to string_view since this is also called with Symbols
for (const auto & s : ss) size += sep.size() + std::string_view(s).size();
std::string s;
s.reserve(size);
for (auto & i : ss) {
if (s.size() != 0) s += sep;
s += i;
}
return s;
}
template<class ... Parts>
auto concatStrings(Parts && ... parts)
-> std::enable_if_t<(... && std::is_convertible_v<Parts, std::string_view>), std::string>
{
std::string_view views[sizeof...(parts)] = { parts... };
return concatStringsSep({}, views);
}
/**
* Add quotes around a collection of strings.
*/
template<class C> Strings quoteStrings(const C & c)
{
Strings res;
for (auto & s : c)
res.push_back("'" + s + "'");
return res;
}
/**
* Remove trailing whitespace from a string.
*
* \todo return std::string_view.
*/
std::string chomp(std::string_view s);
/**
* Remove whitespace from the start and end of a string.
*/
std::string trim(std::string_view s, std::string_view whitespace = " \n\r\t");
/**
* Replace all occurrences of a string inside another string.
*/
std::string replaceStrings(
std::string s,
std::string_view from,
std::string_view to);
/**
* Rewrites a string given a map of replacements, applying the replacements in
* sorted order, only once, considering only the strings appearing in the input
* string in performing replacement.
*
* - Replacements are not performed on intermediate strings. That is, for an input
* `"abb"` with replacements `{"ab" -> "ba"}`, the result is `"bab"`.
* - Transitive replacements are not performed. For example, for the input `"abcde"`
* with replacements `{"a" -> "b", "b" -> "c", "e" -> "b"}`, the result is
* `"bccdb"`.
*/
class Rewriter
{
private:
std::string initials;
std::map<std::string, std::string> rewrites;
public:
explicit Rewriter(std::map<std::string, std::string> rewrites);
std::string operator()(std::string s);
};
inline std::string rewriteStrings(std::string s, const StringMap & rewrites)
{
return Rewriter(rewrites)(s);
}
/**
* Parse a string into an integer.
*/
template<class N>
std::optional<N> string2Int(const std::string_view s);
/**
* Like string2Int(), but support an optional suffix 'K', 'M', 'G' or
* 'T' denoting a binary unit prefix.
*/
template<class N>
N string2IntWithUnitPrefix(std::string_view s)
{
N multiplier = 1;
if (!s.empty()) {
char u = std::toupper(*s.rbegin());
if (std::isalpha(u)) {
if (u == 'K') multiplier = 1ULL << 10;
else if (u == 'M') multiplier = 1ULL << 20;
else if (u == 'G') multiplier = 1ULL << 30;
else if (u == 'T') multiplier = 1ULL << 40;
else throw UsageError("invalid unit specifier '%1%'", u);
s.remove_suffix(1);
}
}
if (auto n = string2Int<N>(s))
return *n * multiplier;
throw UsageError("'%s' is not an integer", s);
}
/**
* Parse a string into a float.
*/
template<class N>
std::optional<N> string2Float(const std::string_view s);
/**
* Convert a little-endian integer to host order.
*/
template<typename T>
T readLittleEndian(unsigned char * p)
{
T x = 0;
for (size_t i = 0; i < sizeof(x); ++i, ++p) {
x |= ((T) *p) << (i * 8);
}
return x;
}
/**
* Convert a string to lower case.
*/
std::string toLower(const std::string & s);
/**
* Escape a string as a shell word.
*/
std::string shellEscape(const std::string_view s);
/**
* Base64 encoding/decoding.
*/
std::string base64Encode(std::string_view s);
std::string base64Decode(std::string_view s);
/**
* Remove common leading whitespace from the lines in the string
* 's'. For example, if every line is indented by at least 3 spaces,
* then we remove 3 spaces from the start of every line.
*/
std::string stripIndentation(std::string_view s);
/**
* Get the prefix of 's' up to and excluding the next line break (LF
* optionally preceded by CR), and the remainder following the line
* break.
*/
std::pair<std::string_view, std::string_view> getLine(std::string_view s);
std::string showBytes(uint64_t bytes);
/**
* Provide an addition operator between strings and string_views
* inexplicably omitted from the standard library.
*/
inline std::string operator + (const std::string & s1, std::string_view s2)
{
auto s = s1;
s.append(s2);
return s;
}
inline std::string operator + (std::string && s, std::string_view s2)
{
s.append(s2);
return std::move(s);
}
inline std::string operator + (std::string_view s1, const char * s2)
{
std::string s;
s.reserve(s1.size() + strlen(s2));
s.append(s1);
s.append(s2);
return s;
}
}
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