1 files changed, 198 insertions, 0 deletions
diff --git a/third_party/nix/src/libutil/json.cc b/third_party/nix/src/libutil/json.cc
new file mode 100644
index 000000000000..59ff74f5796f
--- /dev/null
+++ b/third_party/nix/src/libutil/json.cc
@@ -0,0 +1,198 @@
+#include "libutil/json.hh"
+
+#include <cstring>
+#include <iomanip>
+
+namespace nix {
+
+void toJSON(std::ostream& str, const char* start, const char* end) {
+  str << '"';
+  for (auto i = start; i != 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 >= 0 && *i < 32) {
+      str << "\\u" << std::setfill('0') << std::setw(4) << std::hex
+          << static_cast<uint16_t>(*i) << std::dec;
+    } else {
+      str << *i;
+    }
+  }
+  str << '"';
+}
+
+void toJSON(std::ostream& str, const char* s) {
+  if (s == nullptr) {
+    str << "null";
+  } else {
+    toJSON(str, s, s + strlen(s));
+  }
+}
+
+template <>
+void toJSON<int>(std::ostream& str, const int& n) {
+  str << n;
+}
+template <>
+void toJSON<unsigned int>(std::ostream& str, const unsigned int& n) {
+  str << n;
+}
+template <>
+void toJSON<long>(std::ostream& str, const long& n) {
+  str << n;
+}
+template <>
+void toJSON<unsigned long>(std::ostream& str, const unsigned long& n) {
+  str << n;
+}
+template <>
+void toJSON<long long>(std::ostream& str, const long long& n) {
+  str << n;
+}
+template <>
+void toJSON<unsigned long long>(std::ostream& str,
+                                const unsigned long long& n) {
+  str << n;
+}
+template <>
+void toJSON<float>(std::ostream& str, const float& n) {
+  str << n;
+}
+template <>
+void toJSON<double>(std::ostream& str, const double& n) {
+  str << n;
+}
+
+template <>
+void toJSON<std::string>(std::ostream& str, const std::string& s) {
+  toJSON(str, s.c_str(), s.c_str() + s.size());
+}
+
+template <>
+void toJSON<bool>(std::ostream& str, const bool& b) {
+  str << (b ? "true" : "false");
+}
+
+template <>
+void toJSON<std::nullptr_t>(std::ostream& str, const std::nullptr_t& b) {
+  str << "null";
+}
+
+JSONWriter::JSONWriter(std::ostream& str, bool indent)
+    : state(new JSONState(str, indent)) {
+  state->stack++;
+}
+
+JSONWriter::JSONWriter(JSONState* state) : state(state) { state->stack++; }
+
+JSONWriter::~JSONWriter() {
+  if (state != nullptr) {
+    assertActive();
+    state->stack--;
+    if (state->stack == 0) {
+      delete state;
+    }
+  }
+}
+
+void JSONWriter::comma() {
+  assertActive();
+  if (first) {
+    first = false;
+  } else {
+    state->str << ',';
+  }
+  if (state->indent) {
+    indent();
+  }
+}
+
+void JSONWriter::indent() {
+  state->str << '\n' << std::string(state->depth * 2, ' ');
+}
+
+void JSONList::open() {
+  state->depth++;
+  state->str << '[';
+}
+
+JSONList::~JSONList() {
+  state->depth--;
+  if (state->indent && !first) {
+    indent();
+  }
+  state->str << "]";
+}
+
+JSONList JSONList::list() {
+  comma();
+  return JSONList(state);
+}
+
+JSONObject JSONList::object() {
+  comma();
+  return JSONObject(state);
+}
+
+JSONPlaceholder JSONList::placeholder() {
+  comma();
+  return JSONPlaceholder(state);
+}
+
+void JSONObject::open() {
+  state->depth++;
+  state->str << '{';
+}
+
+JSONObject::~JSONObject() {
+  if (state != nullptr) {
+    state->depth--;
+    if (state->indent && !first) {
+      indent();
+    }
+    state->str << "}";
+  }
+}
+
+void JSONObject::attr(const std::string& s) {
+  comma();
+  toJSON(state->str, s);
+  state->str << ':';
+  if (state->indent) {
+    state->str << ' ';
+  }
+}
+
+JSONList JSONObject::list(const std::string& name) {
+  attr(name);
+  return JSONList(state);
+}
+
+JSONObject JSONObject::object(const std::string& name) {
+  attr(name);
+  return JSONObject(state);
+}
+
+JSONPlaceholder JSONObject::placeholder(const std::string& name) {
+  attr(name);
+  return JSONPlaceholder(state);
+}
+
+JSONList JSONPlaceholder::list() {
+  assertValid();
+  first = false;
+  return JSONList(state);
+}
+
+JSONObject JSONPlaceholder::object() {
+  assertValid();
+  first = false;
+  return JSONObject(state);
+}
+
+}  // namespace nix