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#include "print.hh"
#include <unordered_set>
namespace nix {
std::ostream &
printLiteralString(std::ostream & str, const std::string_view string)
{
str << "\"";
for (auto i = string.begin(); i != string.end(); ++i) {
if (*i == '\"' || *i == '\\') str << "\\" << *i;
else if (*i == '\n') str << "\\n";
else if (*i == '\r') str << "\\r";
else if (*i == '\t') str << "\\t";
else if (*i == '$' && *(i+1) == '{') str << "\\" << *i;
else str << *i;
}
str << "\"";
return str;
}
std::ostream &
printLiteralBool(std::ostream & str, bool boolean)
{
str << (boolean ? "true" : "false");
return str;
}
// Returns `true' is a string is a reserved keyword which requires quotation
// when printing attribute set field names.
//
// This list should generally be kept in sync with `./lexer.l'.
// You can test if a keyword needs to be added by running:
// $ nix eval --expr '{ <KEYWORD> = 1; }'
// For example `or' doesn't need to be quoted.
bool isReservedKeyword(const std::string_view str)
{
static const std::unordered_set<std::string_view> reservedKeywords = {
"if", "then", "else", "assert", "with", "let", "in", "rec", "inherit"
};
return reservedKeywords.contains(str);
}
std::ostream &
printIdentifier(std::ostream & str, std::string_view s) {
if (s.empty())
str << "\"\"";
else if (isReservedKeyword(s))
str << '"' << s << '"';
else {
char c = s[0];
if (!((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_')) {
printLiteralString(str, s);
return str;
}
for (auto c : s)
if (!((c >= 'a' && c <= 'z') ||
(c >= 'A' && c <= 'Z') ||
(c >= '0' && c <= '9') ||
c == '_' || c == '\'' || c == '-')) {
printLiteralString(str, s);
return str;
}
str << s;
}
return str;
}
static bool isVarName(std::string_view s)
{
if (s.size() == 0) return false;
if (isReservedKeyword(s)) return false;
char c = s[0];
if ((c >= '0' && c <= '9') || c == '-' || c == '\'') return false;
for (auto & i : s)
if (!((i >= 'a' && i <= 'z') ||
(i >= 'A' && i <= 'Z') ||
(i >= '0' && i <= '9') ||
i == '_' || i == '-' || i == '\''))
return false;
return true;
}
std::ostream &
printAttributeName(std::ostream & str, std::string_view name) {
if (isVarName(name))
str << name;
else
printLiteralString(str, name);
return str;
}
}
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