Refactor numerical parsing in XML.

PiperOrigin-RevId: 653979240
Change-Id: I4d39f4041b88396193eb35f0cc393141d64f6fc0

src/user/user_api.cc

@@ -27,7 +27,12 @@
 #include "user/user_model.h"
 #include "user/user_objects.h"
 #include "user/user_cache.h"
-#include "xml/xml_util.h"
+
+namespace {
+
+using mujoco::user::StringToVector;
+
+}  // namespace
 
 // global cache size in bytes (default 500MB)
 static constexpr std::size_t kGlobalCacheSize = 500 * (1 << 20);
@@ -892,7 +897,7 @@ mjtByte mjs_setInStringVec(mjStringVec* dest, int i, const char* text) {
 // split text and copy into string array
 void mjs_setStringVec(mjStringVec* dest, const char* text) {
   std::vector<std::string>* v = static_cast<std::vector<std::string>*>(dest);
-  *v = mjXUtil::String2Vector<std::string>(text);
+  *v = StringToVector<std::string>(text);
 }
 
 

src/user/user_composite.cc

@@ -36,12 +36,11 @@
 #include "user/user_model.h"
 #include "user/user_objects.h"
 #include "user/user_util.h"
-#include "xml/xml_util.h"
 
 namespace {
 namespace mju = ::mujoco::util;
-using std::vector;
-using std::string;
+using mujoco::user::VectorToString;
+using mujoco::user::StringToVector;
 }  // namespace
 
 // strncpy with 0, return false
@@ -418,12 +417,12 @@ bool mjCComposite::MakeParticle(mjCModel* model, mjsBody* body, char* error, int
         }
       }
     }
-    mjXUtil::Vector2String(userface, face);
+    userface = VectorToString(face);
   } else {
     dim = 2;  // can only load a surface for now
-    face = mjXUtil::String2Vector<int>(userface);
+    face = StringToVector<int>(userface);
     for (int i=0; i<face.size(); face[i++]--) {};
-    mjXUtil::Vector2String(userface, face);
+    userface = VectorToString(face);
   }
 
   // compute volume
@@ -438,7 +437,7 @@ bool mjCComposite::MakeParticle(mjCModel* model, mjsBody* body, char* error, int
     }
   }
   if (!userface.empty()) {
-    face = mjXUtil::String2Vector<int>(userface);
+    face = StringToVector<int>(userface);
     for (int j=0; j<face.size()/3; j++) {
       double area[3];
       double edge1[3];
@@ -1307,7 +1306,7 @@ void mjCComposite::MakeSkin2(mjCModel* model, mjtNum inflate) {
   // copy skin from existing mesh
   if (type==mjCOMPTYPE_PARTICLE && username.empty()) {
     std::vector<int> skinface;
-    skinface = mjXUtil::String2Vector<int>(userface);
+    skinface = StringToVector<int>(userface);
     int nvert = uservert.size()/3;
 
     for (int j=0; j<2; j++) {
@@ -2034,9 +2033,9 @@ void mjCComposite::MakeSkin2Subgrid(mjCModel* model, mjtNum inflate) {
 // add skin to 3D
 void mjCComposite::MakeSkin3(mjCModel* model) {
   int vcnt = 0;
-  std::map<string, int> vmap;
+  std::map<std::string, int> vmap;
   char txt[100], cnt0[10], cnt1[10], cnt2[10];
-  string fmt;
+  std::string fmt;
 
   // string counts
   mju::sprintf_arr(cnt0, "%d", count[0]-1);
@@ -2056,17 +2055,17 @@ void mjCComposite::MakeSkin3(mjCModel* model) {
   if (type==mjCOMPTYPE_BOX || type==mjCOMPTYPE_PARTICLE) {
     // z-faces
     MakeSkin3Box(skin, count[0], count[1], 1, vcnt, "%sB%d_%d_0");
-    fmt = "%sB%d_%d_" + string(cnt2);
+    fmt = "%sB%d_%d_" + std::string(cnt2);
     MakeSkin3Box(skin, count[0], count[1], 0, vcnt, fmt.c_str());
 
     // y-faces
     MakeSkin3Box(skin, count[0], count[2], 0, vcnt, "%sB%d_0_%d");
-    fmt = "%sB%d_" + string(cnt1) + "_%d";
+    fmt = "%sB%d_" + std::string(cnt1) + "_%d";
     MakeSkin3Box(skin, count[0], count[2], 1, vcnt, fmt.c_str());
 
     // x-faces
     MakeSkin3Box(skin, count[1], count[2], 1, vcnt, "%sB0_%d_%d");
-    fmt = "%sB" + string(cnt0) + "_%d_%d";
+    fmt = "%sB" + std::string(cnt0) + "_%d_%d";
     MakeSkin3Box(skin, count[1], count[2], 0, vcnt, fmt.c_str());
   }
 
@@ -2112,17 +2111,17 @@ void mjCComposite::MakeSkin3(mjCModel* model) {
 
     // y-faces
     MakeSkin3Smooth(skin, count[0], count[2], 0, vmap, "%sB%d_0_%d");
-    fmt = "%sB%d_" + string(cnt1) + "_%d";
+    fmt = "%sB%d_" + std::string(cnt1) + "_%d";
     MakeSkin3Smooth(skin, count[0], count[2], 1, vmap, fmt.c_str());
 
     // x-faces
     MakeSkin3Smooth(skin, count[1], count[2], 1, vmap, "%sB0_%d_%d");
-    fmt = "%sB" + string(cnt0) + "_%d_%d";
+    fmt = "%sB" + std::string(cnt0) + "_%d_%d";
     MakeSkin3Smooth(skin, count[1], count[2], 0, vmap, fmt.c_str());
 
     // z-faces, boxy-type
     MakeSkin3Box(skin, count[0], count[1], 1, vcnt, "%sB%d_%d_0");
-    fmt = "%sB%d_%d_" + string(cnt2);
+    fmt = "%sB%d_%d_" + std::string(cnt2);
     MakeSkin3Box(skin, count[0], count[1], 0, vcnt, fmt.c_str());
   }
 
@@ -2172,17 +2171,17 @@ void mjCComposite::MakeSkin3(mjCModel* model) {
 
     // z-faces
     MakeSkin3Smooth(skin, count[0], count[1], 1, vmap, "%sB%d_%d_0");
-    fmt = "%sB%d_%d_" + string(cnt2);
+    fmt = "%sB%d_%d_" + std::string(cnt2);
     MakeSkin3Smooth(skin, count[0], count[1], 0, vmap, fmt.c_str());
 
     // y-faces
     MakeSkin3Smooth(skin, count[0], count[2], 0, vmap, "%sB%d_0_%d");
-    fmt = "%sB%d_" + string(cnt1) + "_%d";
+    fmt = "%sB%d_" + std::string(cnt1) + "_%d";
     MakeSkin3Smooth(skin, count[0], count[2], 1, vmap, fmt.c_str());
 
     // x-faces
     MakeSkin3Smooth(skin, count[1], count[2], 1, vmap, "%sB0_%d_%d");
-    fmt = "%sB" + string(cnt0) + "_%d_%d";
+    fmt = "%sB" + std::string(cnt0) + "_%d_%d";
     MakeSkin3Smooth(skin, count[1], count[2], 0, vmap, fmt.c_str());
   }
 
@@ -2248,7 +2247,8 @@ void mjCComposite::MakeSkin3Box(mjsSkin* skin, int c0, int c1, int side,
 
 // make one face of 3D skin, smooth
 void mjCComposite::MakeSkin3Smooth(mjsSkin* skin, int c0, int c1, int side,
-                                   const std::map<string, int>& vmap, const char* format) {
+                                   const std::map<std::string, int>& vmap,
+                                   const char* format) {
   char txt00[100], txt01[100], txt10[100], txt11[100];
 
   // loop over bodies/vertices of specified face

src/user/user_mesh.cc

@@ -62,13 +62,16 @@
 #include "user/user_objects.h"
 #include "user/user_resource.h"
 #include "user/user_util.h"
-#include "xml/xml_util.h"
 #include <tiny_obj_loader.h>
 
 extern "C" {
 #include "qhull_ra.h"
 }
 
+namespace {
+  using mujoco::user::VectorToString;
+}  // namespace
+
 // compute triangle area, surface normal, center
 static double _triangle(double* normal, double* center,
                         const float* v1, const float* v2, const float* v3) {
@@ -2627,8 +2630,8 @@ void mjCFlex::Compile(const mjVFS* vfs) {
 
   // add plugins
   std::string userface, useredge;
-  mjXUtil::Vector2String(userface, elem_);
-  mjXUtil::Vector2String(useredge, edgeidx);
+  userface = VectorToString(elem_);
+  useredge = VectorToString(edgeidx);
 
   for (const auto& vbodyid : vertbodyid) {
     if (model->Bodies()[vbodyid]->plugin.instance) {

src/user/user_util.cc

@@ -16,11 +16,13 @@
 
 #include <algorithm>
 #include <cctype>
+#include <cerrno>
 #include <climits>
 #include <cmath>
 #include <cstddef>
 #include <cstdint>
 #include <cstdio>
+#include <cstdlib>
 #include <cstring>
 #include <optional>
 #include <sstream>
@@ -32,6 +34,16 @@
 #include <mujoco/mujoco.h>
 #include "engine/engine_crossplatform.h"
 
+
+// workaround with locale bug on some MacOS machines
+#if defined (__APPLE__) && defined (__MACH__)
+#include <xlocale.h>
+#include <locale.h>
+
+#define strtof(X, Y) strtof_l((X), (Y), _c_locale)
+#define strtod(X, Y) strtod_l((X), (Y), _c_locale)
+#endif
+
 // check if numeric variable is defined
 bool mjuu_defined(double num) {
   return !std::isnan(num);
@@ -1137,5 +1149,109 @@ std::vector<uint8_t> FileToMemory(const char* filename) {
   return buffer;
 }
 
-}  // namespace mujoco::user
+// convert vector to string separating elements by whitespace
+template<typename T> std::string VectorToString(const std::vector<T>& v) {
+  std::stringstream ss;
 
+  for (const T& t : v) {
+    ss << t << " ";
+  }
+
+  std::string s = ss.str();
+  if (!s.empty()) s.pop_back();  // remove trailing space
+  return s;
+}
+
+template std::string VectorToString(const std::vector<int>& v);
+template std::string VectorToString(const std::vector<float>& v);
+template std::string VectorToString(const std::vector<double>& v);
+template std::string VectorToString(const std::vector<std::string>& v);
+
+namespace {
+
+template<typename T> T StrToNum(char* str, char** c);
+
+template<> int StrToNum(char* str, char** c) {
+  long n = std::strtol(str, c, 10);
+  if (n < INT_MIN || n > INT_MAX) errno = ERANGE;
+  return n;
+}
+
+template<> float StrToNum(char* str, char** c) {
+  float f = strtof(str, c);
+  if (std::isnan(f)) errno = EDOM;
+  return f;
+}
+
+template<> double StrToNum(char* str, char** c) {
+  double d = strtod(str, c);
+  if (std::isnan(d)) errno = EDOM;
+  return d;
+}
+
+template<> unsigned char StrToNum(char* str, char** c) {
+  long n = std::strtol(str, c, 10);
+  if (n < 0 || n > UCHAR_MAX) errno = ERANGE;
+  return n;
+}
+
+inline bool IsNullOrSpace(char* c) {
+  return std::isspace(static_cast<unsigned char>(*c)) || *c == '\0';
+}
+
+inline char* SkipSpace(char* c) {
+  for (; *c != '\0'; c++) {
+    if (!IsNullOrSpace(c)) {
+      break;
+    }
+  }
+  return c;
+}
+}  // namespace
+
+template <typename T> std::vector<T> StringToVector(char* cs) {
+  std::vector<T> v;
+  char* ch = cs;
+
+  errno = 0;
+  // reserve worst case
+  v.reserve((std::strlen(cs) >> 1) + 1);
+
+  for (;;) {
+    cs = SkipSpace(ch);                      // skip leading spaces
+    if (*cs == '\0') break;                  // end of string
+    T num = StrToNum<T>(cs, &ch);            // parse number
+    if (!IsNullOrSpace(ch)) errno = EINVAL;  // invalid separator
+    if (cs == ch) errno = EINVAL;            // failed to parse number
+    if (errno && errno != EDOM) break;       // NaNs are quietly ignored
+    v.push_back(num);
+  }
+
+  v.shrink_to_fit();
+  return v;
+}
+
+template<> std::vector<std::string> StringToVector(const std::string& s) {
+  std::vector<std::string> v;
+  std::stringstream ss(s);
+  std::string word;
+  while (ss >> word) {
+    v.push_back(word);
+  }
+  return v;
+}
+
+template std::vector<int>    StringToVector(char* cs);
+template std::vector<float>  StringToVector(char* cs);
+template std::vector<double> StringToVector(char* cs);
+
+
+template <typename T> std::vector<T> StringToVector(const std::string& s) {
+  return StringToVector<T>(const_cast<char*>(s.c_str()));
+}
+template std::vector<int>    StringToVector(const std::string& s);
+template std::vector<float>  StringToVector(const std::string& s);
+template std::vector<double> StringToVector(const std::string& s);
+template std::vector<unsigned char> StringToVector(const std::string& s);
+
+}  // namespace mujoco::user

src/user/user_util.h

@@ -235,6 +235,13 @@ class FilePath {
 // read file into memory buffer
 std::vector<uint8_t> FileToMemory(const char* filename);
 
+// convert vector to string separating elements by whitespace
+template<typename T> std::string VectorToString(const std::vector<T>& v);
+
+// convert string to vector
+template<typename T> std::vector<T> StringToVector(char *cs);
+template<typename T> std::vector<T> StringToVector(const std::string& s);
+
 }  // namespace mujoco::user
 
 // strip path from filename

src/xml/xml_native_reader.cc

@@ -1317,17 +1317,17 @@ void mjXReader::OneFlex(XMLElement* elem, mjsFlex* pflex) {
   if (ReadAttrTxt(elem, "body", text, true)) {
     mjs_setStringVec(pflex->vertbody, text.c_str());
   }
-  if (ReadAttrTxt(elem, "vertex", text)) {
-    std::vector<double> vert = String2Vector<double>(text);
-    mjs_setDouble(pflex->vert, vert.data(), vert.size());
+  auto vert = ReadAttrVec<double>(elem, "vertex");
+  if (vert.has_value()) {
+    mjs_setDouble(pflex->vert, vert->data(), vert->size());
   }
-  if (ReadAttrTxt(elem, "element", text, true)) {
-    std::vector<int> elem = String2Vector<int>(text);
-    mjs_setInt(pflex->elem, elem.data(), elem.size());
+  auto element = ReadAttrVec<int>(elem, "element", true);
+  if (element.has_value()) {
+    mjs_setInt(pflex->elem, element->data(), element->size());
   }
-  if (ReadAttrTxt(elem, "texcoord", text)) {
-    std::vector<float> texcoord = String2Vector<float>(text);
-    mjs_setFloat(pflex->texcoord, texcoord.data(), texcoord.size());
+  auto texcoord = ReadAttrVec<float>(elem, "texcoord");
+  if (texcoord.has_value()) {
+    mjs_setFloat(pflex->texcoord, texcoord->data(), texcoord->size());
   }
 
   // contact subelement
@@ -1459,21 +1459,21 @@ void mjXReader::OneSkin(XMLElement* elem, mjsSkin* pskin) {
   ReadAttr(elem, "inflate", 1, &pskin->inflate, text);
 
   // read vertex data
-  if (ReadAttrTxt(elem, "vertex", text)) {
-    std::vector<float> vert = String2Vector<float>(text);
-    mjs_setFloat(pskin->vert, vert.data(), vert.size());
+  auto vertex = ReadAttrVec<float>(elem, "vertex");
+  if (vertex.has_value()) {
+    mjs_setFloat(pskin->vert, vertex->data(), vertex->size());
   }
 
   // read texcoord data
-  if (ReadAttrTxt(elem, "texcoord", text)) {
-    std::vector<float> texcoord = String2Vector<float>(text);
-    mjs_setFloat(pskin->texcoord, texcoord.data(), texcoord.size());
+  auto texcoord = ReadAttrVec<float>(elem, "texcoord");
+  if (texcoord.has_value()) {
+    mjs_setFloat(pskin->texcoord, texcoord->data(), texcoord->size());
   }
 
   // read user face data
-  if (ReadAttrTxt(elem, "face", text)) {
-    std::vector<int> face = String2Vector<int>(text);
-    mjs_setInt(pskin->face, face.data(), face.size());
+  auto face = ReadAttrVec<int>(elem, "face");
+  if (face.has_value()) {
+    mjs_setInt(pskin->face, face->data(), face->size());
   }
 
   // read bones
@@ -1500,14 +1500,16 @@ void mjXReader::OneSkin(XMLElement* elem, mjsSkin* pskin) {
     bindquat.push_back(data[3]);
 
     // read vertid
-    ReadAttrTxt(bone, "vertid", text, true);
-    vector<int> tempid = String2Vector<int>(text);
-    mjs_appendIntVec(pskin->vertid, tempid.data(), tempid.size());
+    auto tempid = ReadAttrVec<int>(bone, "vertid", true);
+    if (tempid.has_value()) {
+      mjs_appendIntVec(pskin->vertid, tempid->data(), tempid->size());
+    }
 
     // read vertweight
-    ReadAttrTxt(bone, "vertweight", text, true);
-    vector<float> tempweight = String2Vector<float>(text);
-    mjs_appendFloatVec(pskin->vertweight, tempweight.data(), tempweight.size());
+    auto tempweight = ReadAttrVec<float>(bone, "vertweight", true);
+    if (tempweight.has_value()) {
+      mjs_appendFloatVec(pskin->vertweight, tempweight->data(), tempweight->size());
+    }
 
     // advance to next bone
     bone = NextSiblingElement(bone, "bone");
@@ -2287,8 +2289,9 @@ void mjXReader::OneComposite(XMLElement* elem, mjsBody* pbody, mjsDefault* def)
   ReadAttrTxt(elem, "curve", curves);
   ReadAttrTxt(elem, "initial", comp.initial);
   ReadAttr(elem, "size", 3, comp.size, text, false, false);
-  if (ReadAttrTxt(elem, "vertex", text)) {
-    comp.uservert = String2Vector<float>(text);
+  auto uservert = ReadAttrVec<float>(elem, "vertex");
+  if (uservert.has_value()) {
+    comp.uservert = std::move(uservert.value());
   }
 
   // shell
@@ -2530,14 +2533,17 @@ void mjXReader::OneFlexcomp(XMLElement* elem, mjsBody* pbody) {
   if (MapValue(elem, "rigid", &n, bool_map, 2)) {
     fcomp.rigid = (n==1);
   }
-  if (ReadAttrTxt(elem, "point", text)){
-    fcomp.point = String2Vector<double>(text);
+  auto point = ReadAttrVec<double>(elem, "point");
+  if (point.has_value()) {
+    fcomp.point = std::move(point.value());
   }
-  if (ReadAttrTxt(elem, "element", text)){
-    fcomp.element = String2Vector<int>(text);
+  auto element = ReadAttrVec<int>(elem, "element");
+  if (element.has_value()) {
+    fcomp.element = std::move(element.value());
   }
-  if (ReadAttrTxt(elem, "texcoord", text)) {
-    fcomp.texcoord = String2Vector<float>(text);
+  auto texcoord = ReadAttrVec<float>(elem, "texcoord");
+  if (texcoord.has_value()) {
+    fcomp.texcoord = std::move(texcoord.value());
   }
 
   // edge
@@ -2575,23 +2581,22 @@ void mjXReader::OneFlexcomp(XMLElement* elem, mjsBody* pbody) {
   // pin
   XMLElement* epin = FirstChildElement(elem, "pin");
   while (epin) {
-    // accumulate id, coord, range
-    if (ReadAttrTxt(epin, "id", text)) {
-      vector<int> v = String2Vector<int>(text);
-      fcomp.pinid.insert(fcomp.pinid.end(), v.begin(), v.end());
+    auto id = ReadAttrVec<int>(epin, "id");
+    if (id.has_value()) {
+      fcomp.pinid.insert(fcomp.pinid.end(), id->begin(), id->end());
     }
-    if (ReadAttrTxt(epin, "range", text)) {
-      vector<int> v = String2Vector<int>(text);
-      fcomp.pinrange.insert(fcomp.pinrange.end(), v.begin(), v.end());
+    auto range = ReadAttrVec<int>(epin, "range");
+    if (range.has_value()) {
+      fcomp.pinrange.insert(fcomp.pinrange.end(), range->begin(), range->end());
     }
-    if (ReadAttrTxt(epin, "grid", text)) {
-
-      vector<int> v = String2Vector<int>(text);
-      fcomp.pingrid.insert(fcomp.pingrid.end(), v.begin(), v.end());
+    auto grid = ReadAttrVec<int>(epin, "grid");
+    if (grid.has_value()) {
+      fcomp.pingrid.insert(fcomp.pingrid.end(), grid->begin(), grid->end());
     }
-    if (ReadAttrTxt(epin, "gridrange", text)) {
-      vector<int> v = String2Vector<int>(text);
-      fcomp.pingridrange.insert(fcomp.pingridrange.end(), v.begin(), v.end());
+    auto gridrange = ReadAttrVec<int>(epin, "gridrange");
+    if (gridrange.has_value()) {
+      fcomp.pingridrange.insert(fcomp.pingridrange.end(),
+                                gridrange->begin(), gridrange->end());
     }
 
     // advance

src/xml/xml_native_writer.cc

@@ -44,6 +44,7 @@ using std::string;
 using tinyxml2::XMLComment;
 using tinyxml2::XMLDocument;
 using tinyxml2::XMLElement;
+using mujoco::user::VectorToString;
 
 }  // namespace
 
@@ -142,19 +143,19 @@ void mjXWriter::OneFlex(XMLElement* elem, const mjCFlex* pflex) {
 
   // data vectors
   if (!pflex->get_vertbody().empty()) {
-    Vector2String(text, pflex->get_vertbody());
+    text = VectorToString(pflex->get_vertbody());
     WriteAttrTxt(elem, "body", text);
   }
   if (!pflex->get_vert().empty()) {
-    Vector2String(text, pflex->get_vert());
+    text = VectorToString(pflex->get_vert());
     WriteAttrTxt(elem, "vertex", text);
   }
   if (!pflex->get_elem().empty()) {
-    Vector2String(text, pflex->get_elem());
+    text = VectorToString(pflex->get_elem());
     WriteAttrTxt(elem, "element", text);
   }
   if (!pflex->get_texcoord().empty()) {
-    Vector2String(text, pflex->get_texcoord());
+    text = VectorToString(pflex->get_texcoord());
     WriteAttrTxt(elem, "texcoord", text);
   }
 
@@ -207,25 +208,25 @@ void mjXWriter::OneMesh(XMLElement* elem, const mjCMesh* pmesh, mjCDef* def) {
 
     // write vertex data
     if (!pmesh->get_uservert().empty()) {
-      Vector2String(text, pmesh->get_uservert());
+      text = VectorToString(pmesh->get_uservert());
       WriteAttrTxt(elem, "vertex", text);
     }
 
     // write normal data
     if (!pmesh->get_usernormal().empty()) {
-      Vector2String(text, pmesh->get_usernormal());
+      text = VectorToString(pmesh->get_usernormal());
       WriteAttrTxt(elem, "normal", text);
     }
 
     // write texcoord data
     if (!pmesh->get_usertexcoord().empty()) {
-      Vector2String(text, pmesh->get_usertexcoord());
+      text = VectorToString(pmesh->get_usertexcoord());
       WriteAttrTxt(elem, "texcoord", text);
     }
 
     // write face data
     if (!pmesh->get_userface().empty()) {
-      Vector2String(text, pmesh->get_userface());
+      text = VectorToString(pmesh->get_userface());
       WriteAttrTxt(elem, "face", text);
     }
   }
@@ -257,17 +258,17 @@ void mjXWriter::OneSkin(XMLElement* elem, const mjCSkin* pskin) {
   // write data if no file
   if (pskin->get_file().empty()) {
     // mesh vert
-    Vector2String(text, pskin->get_vert());
+    text = VectorToString(pskin->get_vert());
     WriteAttrTxt(elem, "vertex", text);
 
     // mesh texcoord
     if (!pskin->get_texcoord().empty()) {
-      Vector2String(text, pskin->get_texcoord());
+      text = VectorToString(pskin->get_texcoord());
       WriteAttrTxt(elem, "texcoord", text);
     }
 
     // mesh face
-    Vector2String(text, pskin->get_face());
+    text = VectorToString(pskin->get_face());
     WriteAttrTxt(elem, "face", text);
 
     // bones
@@ -281,11 +282,11 @@ void mjXWriter::OneSkin(XMLElement* elem, const mjCSkin* pskin) {
       WriteAttr(bone, "bindquat", 4, pskin->get_bindquat().data()+4*i);
 
       // write vertid
-      Vector2String(text, pskin->get_vertid()[i]);
+      text = VectorToString(pskin->get_vertid()[i]);
       WriteAttrTxt(bone, "vertid", text);
 
       // write vertweight
-      Vector2String(text, pskin->get_vertweight()[i]);
+      text = VectorToString(pskin->get_vertweight()[i]);
       WriteAttrTxt(bone, "vertweight", text);
     }
   }

src/xml/xml_util.cc

@@ -43,10 +43,6 @@
 
 namespace {
 
-using std::size_t;
-using std::string;
-using std::stringstream;
-using std::vector;
 using tinyxml2::XMLAttribute;
 using tinyxml2::XMLElement;
 
@@ -238,7 +234,7 @@ mjXSchema::mjXSchema(const char* schema[][mjXATTRNUM], unsigned nrow) {
 
 
 // get pointer to error message
-string mjXSchema::GetError() {
+std::string mjXSchema::GetError() {
   return error;
 }
 
@@ -256,7 +252,7 @@ static void printspace(std::stringstream& str, int n, const char* space) {
 // print schema as text
 void mjXSchema::Print(std::stringstream& str, int level) const {
   // replace body with (world)body
-  string name1 = (name_ == "body") ? "(world)body" : name_;
+  std::string name1 = (name_ == "body") ? "(world)body" : name_;
 
   // space, name, type
   printspace(str, 3*level, " ");
@@ -290,7 +286,7 @@ void mjXSchema::Print(std::stringstream& str, int level) const {
 // print schema as HTML table
 void mjXSchema::PrintHTML(std::stringstream& str, int level, bool pad) const {
   // replace body with (world)body
-  string name1 = (name_ == "body" ? "(world)body" : name_);
+  std::string name1 = (name_ == "body" ? "(world)body" : name_);
 
   // open table
   if (level==0) {
@@ -377,7 +373,7 @@ XMLElement* mjXSchema::Check(XMLElement* elem, int level) {
   const XMLAttribute* attribute = elem->FirstAttribute();
   for (; attribute != nullptr; attribute = attribute->Next()) {
     if (attr_.find(attribute->Name()) == attr_.end()) {
-      error = "unrecognized attribute: '" + string(attribute->Name()) + "'";
+      error = "unrecognized attribute: '" + std::string(attribute->Name()) + "'";
       return elem;
     }
   }
@@ -541,7 +537,7 @@ template bool mjXUtil::SameVector(const unsigned char* vec1, const unsigned char
 
 
 // find string in map, return corresponding integer (-1: not found)
-int mjXUtil::FindKey(const mjMap* map, int mapsz, string key) {
+int mjXUtil::FindKey(const mjMap* map, int mapsz, std::string key) {
   for (int i=0; i<mapsz; i++) {
     if (map[i].key == key) {
       return map[i].value;
@@ -554,7 +550,7 @@ int mjXUtil::FindKey(const mjMap* map, int mapsz, string key) {
 
 
 // find integer in map, return corresponding string ("": not found)
-string mjXUtil::FindValue(const mjMap* map, int mapsz, int value) {
+std::string mjXUtil::FindValue(const mjMap* map, int mapsz, int value) {
   for (int i=0; i<mapsz; i++) {
     if (map[i].value == value) {
       return map[i].key;
@@ -570,9 +566,22 @@ string mjXUtil::FindValue(const mjMap* map, int mapsz, int value) {
 template<typename T>
 std::optional<std::vector<T>> mjXUtil::ReadAttrVec(XMLElement* elem, const char* attr,
                                                    bool required) {
-  std::vector<T> vec;
-  ReadAttrValues<T>(elem, attr, [&](int i, T num) { vec.push_back(num); });
-  if (!vec.size()) {
+  std::vector<T> v;
+  const char* raw_cstr = elem->Attribute(attr);
+  if (raw_cstr) {
+    v = mujoco::user::StringToVector<T>(raw_cstr);
+    if (errno == EDOM) {
+      mju_warning("XML contains a 'NaN'. Please check it carefully.");
+    } else if (errno == ERANGE) {
+      throw mjXError(elem, "number is too large in attribute '%s'", attr);
+    } else if (errno == EINVAL) {
+      throw mjXError(elem, "bad format in attribute '%s'", attr);
+    } else if (errno != 0) {
+      throw mjXError(elem, "unknown error in attribute '%s'", attr);
+    }
+  }
+
+  if (!v.size()) {
     if (required) {
       throw mjXError(elem, "required attribute missing: '%s'", attr);
     } else {
@@ -580,7 +589,7 @@ std::optional<std::vector<T>> mjXUtil::ReadAttrVec(XMLElement* elem, const char*
     }
   }
 
-  return vec;
+  return v;
 }
 
 template std::optional<std::vector<double>>
@@ -651,7 +660,7 @@ mjXUtil::ReadAttrNum(XMLElement* elem, const char* attr, bool required);
 //  return number of elements found
 template<typename T>
 int mjXUtil::ReadAttr(XMLElement* elem, const char* attr, const int len,
-                      T* data, string& text, bool required, bool exact) {
+                      T* data, std::string& text, bool required, bool exact) {
   auto maybe_vec = ReadAttrVec<T>(elem, attr, required);
   if (!maybe_vec.has_value()) {
     return 0;
@@ -672,21 +681,21 @@ int mjXUtil::ReadAttr(XMLElement* elem, const char* attr, const int len,
 }
 
 template int mjXUtil::ReadAttr(XMLElement* elem, const char* attr, int len,
-                               double* data, string& text, bool required, bool exact);
+                               double* data, std::string& text, bool required, bool exact);
 
 template int mjXUtil::ReadAttr(XMLElement* elem, const char* attr, int len,
-                               float* data, string& text, bool required, bool exact);
+                               float* data, std::string& text, bool required, bool exact);
 
 template int mjXUtil::ReadAttr(XMLElement* elem, const char* attr, int len,
-                               int* data, string& text, bool required, bool exact);
+                               int* data, std::string& text, bool required, bool exact);
 
 template int mjXUtil::ReadAttr(XMLElement* elem, const char* attr, int len,
-                               unsigned char* data, string& text, bool required,
+                               unsigned char* data, std::string& text, bool required,
                                bool exact);
 
 // read quaternion attribute
 //  throw error if identically zero
-int mjXUtil::ReadQuat(XMLElement* elem, const char* attr, double* data, string& text,
+int mjXUtil::ReadQuat(XMLElement* elem, const char* attr, double* data, std::string& text,
                       bool required) {
   ReadAttr(elem, attr, /*len=*/4, data, text, required, /*exact=*/true);
 
@@ -700,7 +709,7 @@ int mjXUtil::ReadQuat(XMLElement* elem, const char* attr, double* data, string&
 
 // read DOUBLE array into C++ vector, return number read
 int mjXUtil::ReadVector(XMLElement* elem, const char* attr,
-                        vector<double>& vec, string& text, bool required) {
+                        std::vector<double>& vec, std::string& text, bool required) {
   auto maybe_vec = ReadAttrVec<double>(elem, attr, required);
   if (!maybe_vec.has_value()) {
     return 0;
@@ -713,7 +722,8 @@ int mjXUtil::ReadVector(XMLElement* elem, const char* attr,
 
 
 // read text field
-bool mjXUtil::ReadAttrTxt(tinyxml2::XMLElement* elem, const char* attr, string& text, bool required) {
+bool mjXUtil::ReadAttrTxt(tinyxml2::XMLElement* elem, const char* attr,
+                          std::string& text, bool required) {
   auto maybe_str = ReadAttrStr(elem, attr, required);
   if (!maybe_str.has_value()) {
     return false;
@@ -735,92 +745,9 @@ bool mjXUtil::ReadAttrInt(XMLElement* elem, const char* attr, int* data, bool re
 }
 
 
-
-template<> int mjXUtil::StrToNum(char* str, char** c) {
-  return std::strtol(str, c, 10);
-}
-
-template<> float mjXUtil::StrToNum(char* str, char** c) {
-  return std::strtof(str, c);
-}
-
-template<> double mjXUtil::StrToNum(char* str, char** c) {
-  return std::strtod(str, c);
-}
-
-template <typename T>
-std::vector<T> mjXUtil::String2Vector(const std::string& s) {
-  errno = 0;
-  std::vector<T> v;
-  char* cs = (char*) s.c_str();
-  char* ch = cs;
-
-  // reserve worst case
-  v.reserve((s.size() >> 1) + 1);
-
-  for (;;) {
-    cs = ch;
-    T num = StrToNum<T>(cs, &ch);
-    if (cs == ch) break;
-    if (errno) break;
-    v.push_back(num);
-  }
-
-  v.shrink_to_fit();
-  return v;
-}
-
-template std::vector<int> mjXUtil::String2Vector(const std::string& s);
-template std::vector<float> mjXUtil::String2Vector(const std::string& s);
-template std::vector<double> mjXUtil::String2Vector(const std::string& s);
-template<>
-std::vector<std::string> mjXUtil::String2Vector(const std::string& s) {
-  std::vector<std::string> v;
-  std::stringstream ss(s);
-  std::string word;
-  while (ss >> word) {
-    v.push_back(word);
-  }
-  return v;
-}
-
-
-
 // write vector<float> to string
-void mjXUtil::Vector2String(string& txt, const vector<string>& vec) {
-  stringstream strm;
-
-  for (size_t i=0; i<vec.size(); i++) {
-    if (i>0) {
-      strm << " ";
-    }
-    strm << vec[i];
-  }
-
-  txt = strm.str();
-}
-
-
-
-// write vector<double> to string
-void mjXUtil::Vector2String(string& txt, const vector<double>& vec) {
-  stringstream strm;
-
-  for (size_t i=0; i<vec.size(); i++) {
-    if (i>0) {
-      strm << " ";
-    }
-    strm << vec[i];
-  }
-
-  txt = strm.str();
-}
-
-
-
-// write vector<float> to string
-void mjXUtil::Vector2String(string& txt, const vector<float>& vec, int ncol) {
-  stringstream strm;
+void mjXUtil::Vector2String(std::string& txt, const std::vector<float>& vec, int ncol) {
+  std::stringstream strm;
 
   for (size_t i=0; i<vec.size(); i++) {
     if (ncol && (i % ncol) == 0) {
@@ -834,26 +761,8 @@ void mjXUtil::Vector2String(string& txt, const vector<float>& vec, int ncol) {
   txt = strm.str();
 }
 
-
-
-// write vector<int> to string
-void mjXUtil::Vector2String(string& txt, const vector<int>& vec) {
-  stringstream strm;
-
-  for (size_t i=0; i<vec.size(); i++) {
-    if (i>0) {
-      strm << " ";
-    }
-    strm << vec[i];
-  }
-
-  txt = strm.str();
-}
-
-
-
 // find subelement with given name, make sure it is unique
-XMLElement* mjXUtil::FindSubElem(XMLElement* elem, string name, bool required) {
+XMLElement* mjXUtil::FindSubElem(XMLElement* elem, std::string name, bool required) {
   XMLElement* subelem = 0;
 
   XMLElement* iter = elem->FirstChildElement();
@@ -924,7 +833,7 @@ static int Round(double x) {
 
 // write attribute
 template<typename T>
-void mjXUtil::WriteAttr(XMLElement* elem, string name, int n, const T* data, const T* def,
+void mjXUtil::WriteAttr(XMLElement* elem, std::string name, int n, const T* data, const T* def,
                         bool trim) {
   // make sure all are defined
   if constexpr (std::is_floating_point_v<T>) {
@@ -948,7 +857,7 @@ void mjXUtil::WriteAttr(XMLElement* elem, string name, int n, const T* data, con
   }
 
   // increase precision for testing
-  stringstream stream;
+  std::stringstream stream;
   stream.precision(mujoco::_mjPRIVATE__get_xml_precision());
 
   // process all numbers
@@ -972,22 +881,22 @@ void mjXUtil::WriteAttr(XMLElement* elem, string name, int n, const T* data, con
 }
 
 
-template void mjXUtil::WriteAttr(XMLElement* elem, string name, int n,
+template void mjXUtil::WriteAttr(XMLElement* elem, std::string name, int n,
                                  const double* data, const double* def, bool trim);
 
-template void mjXUtil::WriteAttr(XMLElement* elem, string name, int n,
+template void mjXUtil::WriteAttr(XMLElement* elem, std::string name, int n,
                                  const float* data, const float* def, bool trim);
 
-template void mjXUtil::WriteAttr(XMLElement* elem, string name, int n,
+template void mjXUtil::WriteAttr(XMLElement* elem, std::string name, int n,
                                  const int* data, const int* def, bool trim);
 
-template void mjXUtil::WriteAttr(XMLElement* elem, string name, int n,
+template void mjXUtil::WriteAttr(XMLElement* elem, std::string name, int n,
                                  const unsigned char* data,
                                  const unsigned char* def, bool trim);
 
 
 // write vector<double> attribute, default = zero array
-void mjXUtil::WriteVector(XMLElement* elem, string name, const vector<double>& vec) {
+void mjXUtil::WriteVector(XMLElement* elem, std::string name, const std::vector<double>& vec) {
   // proceed only if non-zero found
   bool ok = false;
   for (size_t i=0; i<vec.size(); i++) {
@@ -1006,8 +915,8 @@ void mjXUtil::WriteVector(XMLElement* elem, string name, const vector<double>& v
 
 
 // write vector<double> attribute, default with same size
-void mjXUtil::WriteVector(XMLElement* elem, string name, const vector<double>& vec,
-                          const vector<double>& def) {
+void mjXUtil::WriteVector(XMLElement* elem, std::string name, const std::vector<double>& vec,
+                          const std::vector<double>& def) {
   // proceed only if non-zero found
   bool ok = false;
   for (size_t i=0; i<vec.size(); i++) {
@@ -1026,7 +935,7 @@ void mjXUtil::WriteVector(XMLElement* elem, string name, const vector<double>& v
 
 
 // write attribute- string
-void mjXUtil::WriteAttrTxt(XMLElement* elem, string name, string value) {
+void mjXUtil::WriteAttrTxt(XMLElement* elem, std::string name, std::string value) {
   // skip if value is empty
   if (value.empty()) {
     return;
@@ -1039,7 +948,7 @@ void mjXUtil::WriteAttrTxt(XMLElement* elem, string name, string value) {
 
 
 // write attribute- single int
-void mjXUtil::WriteAttrInt(XMLElement* elem, string name, int data, int def) {
+void mjXUtil::WriteAttrInt(XMLElement* elem, std::string name, int data, int def) {
   // skip default
   if (data==def) {
     return;
@@ -1051,7 +960,7 @@ void mjXUtil::WriteAttrInt(XMLElement* elem, string name, int data, int def) {
 
 
 // write attribute- keyword
-void mjXUtil::WriteAttrKey(XMLElement* elem, string name,
+void mjXUtil::WriteAttrKey(XMLElement* elem, std::string name,
                            const mjMap* map, int mapsz, int data, int def) {
   // skip default
   if (data==def) {

src/xml/xml_util.h

@@ -163,21 +163,9 @@ class mjXUtil {
   static bool ReadAttrInt(tinyxml2::XMLElement* elem, const char* attr, int* data,
                           bool required = false);
 
-  // convert string to vector
-  template<typename T>
-  static std::vector<T> String2Vector(const std::string& s);
-
-  // write vector<string> to string
-  static void Vector2String(std::string& txt, const std::vector<std::string>& vec);
-
-  // write vector<double> to string
-  static void Vector2String(std::string& txt, const std::vector<double>& vec);
-
   // write vector<float> to string
   static void Vector2String(std::string& txt, const std::vector<float>& vec, int ncol = 0);
 
-  // write vector<int> to string
-  static void Vector2String(std::string& txt, const std::vector<int>& vec);
 
   // find subelement with given name, make sure it is unique
   static tinyxml2::XMLElement* FindSubElem(tinyxml2::XMLElement* elem, std::string name,
@@ -212,8 +200,6 @@ class mjXUtil {
   template<typename T>
   static bool ReadAttrValues(tinyxml2::XMLElement* elem, const char* attr,
                              std::function<void (int, T)> push, int max = -1);
-  template<typename T> static T StrToNum(char* str, char** c);
-
 };
 
 #endif  // MUJOCO_SRC_XML_XML_UTIL_H_

test/user/user_util_test.cc

@@ -16,93 +16,164 @@
 
 #include "src/user/user_util.h"
 
+#include <cerrno>
+#include <string>
+#include <vector>
+
 #include <gtest/gtest.h>
+#include <gmock/gmock.h>
+#include <mujoco/mujoco.h>
+#include "test/fixture.h"
 
 namespace mujoco {
 namespace {
 
 using user::FilePath;
+using user::StringToVector;
+using user::VectorToString;
+using ::testing::ElementsAre;
+using ::testing::IsNan;
 
-TEST(UserUtilTest, PathReduce) {
+using UserUtilTest = MujocoTest;
+
+TEST_F(UserUtilTest, PathReduce) {
   FilePath path = FilePath("/hello/.././world/");
   EXPECT_EQ(path.Str(), "/world/");
 }
 
-TEST(UserUtilTest, PathReduce2) {
+TEST_F(UserUtilTest, PathReduce2) {
   FilePath path = FilePath("../hello/./world/");
   EXPECT_EQ(path.Str(), "../hello/world/");
 }
 
-TEST(UserUtilTest, PathReduceWin) {
+TEST_F(UserUtilTest, PathReduceWin) {
   FilePath path = FilePath("C:\\hello\\..\\world");
   EXPECT_EQ(path.Str(), "C:\\world");
 }
 
-TEST(UserUtilTest, IsAbs) {
+TEST_F(UserUtilTest, IsAbs) {
   EXPECT_TRUE(FilePath("/hello").IsAbs());
   EXPECT_TRUE(FilePath("C:\\hello").IsAbs());
   EXPECT_FALSE(FilePath("hello").IsAbs());
 }
 
-TEST(UserUtilTest, Combine) {
+TEST_F(UserUtilTest, Combine) {
   FilePath path1 = FilePath("/hello");
   FilePath path2 = FilePath("world");
   EXPECT_EQ((path1 + path2).Str(), "/hello/world");
 }
 
-TEST(UserUtilTest, Combine2) {
+TEST_F(UserUtilTest, Combine2) {
   FilePath path1 = FilePath("hello/");
   FilePath path2 = FilePath("world");
   EXPECT_EQ((path1 + path2).Str(), "hello/world");
 }
 
-TEST(UserUtilTest, Combine3) {
+TEST_F(UserUtilTest, Combine3) {
   FilePath path1 = FilePath("/hello");
   FilePath path2 = FilePath("../world");
   EXPECT_EQ((path1 + path2).Str(), "/world");
 }
 
-TEST(UserUtilTest, CombineAbs) {
+TEST_F(UserUtilTest, CombineAbs) {
   FilePath path1 = FilePath("/hello");
   FilePath path2 = FilePath("/world");
   EXPECT_EQ((path1 + path2).Str(), "/world");
 }
 
-TEST(UserUtilTest, Ext) {
+TEST_F(UserUtilTest, Ext) {
   FilePath path = FilePath("/hello/world.txt");
   EXPECT_EQ(path.Ext(), ".txt");
 }
 
-TEST(UserUtilTest, ExtEmpty) {
+TEST_F(UserUtilTest, ExtEmpty) {
   FilePath path = FilePath("/hello/world");
   EXPECT_EQ(path.Ext(), "");
 }
 
-TEST(UserUtilTest, StripExt) {
+TEST_F(UserUtilTest, StripExt) {
   FilePath path = FilePath("/hello/world.txt");
   EXPECT_EQ(path.StripExt().Str(), "/hello/world");
 }
 
-TEST(UserUtilTest, StripPath) {
+TEST_F(UserUtilTest, StripPath) {
   FilePath path = FilePath("/hello/world.txt");
   EXPECT_EQ(path.StripPath().Str(), "world.txt");
 }
 
-TEST(UserUtilTest, StripPathEmpty) {
+TEST_F(UserUtilTest, StripPathEmpty) {
   FilePath path = FilePath("world.txt");
   EXPECT_EQ(path.StripPath().Str(), "world.txt");
 }
 
-TEST(UserUtilTest, StripPathWin) {
+TEST_F(UserUtilTest, StripPathWin) {
   FilePath path = FilePath("\\world.txt");
   EXPECT_EQ(path.StripPath().Str(), "world.txt");
 }
 
 
-TEST(UserUtilTest, StrLower) {
+TEST_F(UserUtilTest, StrLower) {
   FilePath path = FilePath("/HELLO/worlD.txt");
   EXPECT_EQ(path.StrLower(), "/hello/world.txt");
 }
 
+TEST_F(UserUtilTest, StringToVectorFloat) {
+  std::vector<float> v = StringToVector<float>(" 1.2 3.2     5.3 6 ");
+  EXPECT_THAT(v, ElementsAre(1.2, 3.2, 5.3, 6));
+  EXPECT_EQ(errno, 0);
+}
+
+TEST_F(UserUtilTest, StringToVectorEmpty) {
+  std::vector<float> v = StringToVector<float>("   ");
+  EXPECT_THAT(v, ElementsAre());
+  EXPECT_EQ(errno, 0);
+}
+
+TEST_F(UserUtilTest, StringToVectorError) {
+  std::vector<float> v = StringToVector<float>("2.1 3ABCD. /123/122/113");
+  EXPECT_THAT(v, ElementsAre(2.1));
+  EXPECT_EQ(errno, EINVAL);
+}
+
+TEST_F(UserUtilTest, StringToVectorInt) {
+  std::vector<int> v = StringToVector<int>("  -1 3  5 6  ");
+  EXPECT_THAT(v, ElementsAre(-1, 3, 5, 6));
+  EXPECT_EQ(errno, 0);
+}
+
+TEST_F(UserUtilTest, StringToVectorString) {
+  auto v = StringToVector<std::string>(" abc  def ");
+  EXPECT_THAT(v, ElementsAre("abc", "def"));
+}
+
+TEST_F(UserUtilTest, StringToVectorInvalidNumber) {
+  auto v = StringToVector<double>("1 0.1.2.3");
+  EXPECT_THAT(v, ElementsAre(1));
+  EXPECT_EQ(errno, EINVAL);
+}
+
+TEST_F(UserUtilTest, StringToVectorNan) {
+  mju_user_warning = nullptr;
+  auto v = StringToVector<double>("1 2 nan 3.21");
+  EXPECT_THAT(v[2], IsNan());
+  EXPECT_EQ(v[3], 3.21);
+  EXPECT_EQ(errno, EDOM);
+}
+
+TEST_F(UserUtilTest, StringToVectorRange) {
+  auto v = StringToVector<unsigned char>("-10");
+  EXPECT_EQ(errno, ERANGE);
+}
+
+TEST_F(UserUtilTest, VectorToString) {
+  std::vector<double> v = {1.2, 3.2, 5.3, 6};
+  EXPECT_EQ(VectorToString(v), "1.2 3.2 5.3 6");
+}
+
+TEST_F(UserUtilTest, VectorToStringEmpty) {
+  std::vector<double> v;
+  EXPECT_EQ(VectorToString(v), "");
+}
+
 }  // namespace
 }  // namespace mujoco

test/xml/xml_native_reader_test.cc

@@ -345,7 +345,7 @@ TEST_F(XMLReaderTest, InvalidArrayElement) {
   std::array<char, 1024> error;
   mjModel* model = LoadModelFromString(xml, error.data(), error.size());
   ASSERT_THAT(model, IsNull());
-  EXPECT_THAT(error.data(), HasSubstr("problem reading attribute 'axisangle'"));
+  EXPECT_THAT(error.data(), HasSubstr("bad format in attribute 'axisangle'"));
   EXPECT_THAT(error.data(), HasSubstr("line 5"));
 }
 
@@ -396,10 +396,26 @@ TEST_F(XMLReaderTest, InvalidNumber) {
   std::array<char, 1024> error;
   mjModel* model = LoadModelFromString(xml, error.data(), error.size());
   ASSERT_THAT(model, IsNull());
-  EXPECT_THAT(error.data(), HasSubstr("problem reading attribute"));
+  EXPECT_THAT(error.data(), HasSubstr("bad format in attribute 'axisangle'"));
   EXPECT_THAT(error.data(), HasSubstr("line 5"));
 }
 
+TEST_F(XMLReaderTest, InvalidNumberRange) {
+    static constexpr char xml[] = R"(
+  <mujoco>
+    <asset>
+      <mesh name="mesh" file="mesh.stl" face="100000000000000000000000"/>
+    </asset>
+  </mujoco>
+  )";
+  std::array<char, 1024> error;
+  mjModel* model = LoadModelFromString(xml, error.data(), error.size());
+  ASSERT_THAT(model, IsNull());
+  EXPECT_THAT(error.data(),
+              HasSubstr("number is too large in attribute 'face'"));
+  EXPECT_THAT(error.data(), HasSubstr("line 4"));
+}
+
 TEST_F(XMLReaderTest, InvalidNumberOfAttributes) {
   static constexpr char xml[] = R"(
   <mujoco>

test/xml/xml_native_writer_test.cc

@@ -1238,7 +1238,7 @@ TEST_F(XMLWriterTest, SetPrecision) {
   EXPECT_EQ(model->geom_size[1], model_lo->geom_size[1]);
   EXPECT_NE(model->geom_size[2], model_lo->geom_size[2]);
   {
-    // save to XML and re-load with FullFloatPrecision
+    // save to XML and reload with FullFloatPrecision
     // expect to maintain precision
     FullFloatPrecision increase_precision;
     mjModel* model_hi = LoadModelFromString(SaveAndReadXml(model));
@@ -1276,8 +1276,10 @@ TEST_F(XMLWriterLocaleTest, IgnoresLocale) {
     </worldbody>
   </mujoco>
   )";
-  mjModel* model = LoadModelFromString(xml);
-  ASSERT_THAT(model, NotNull());
+
+  std::array<char, 1024> error;
+  mjModel* model = LoadModelFromString(xml, error.data(), error.size());
+  ASSERT_THAT(model, NotNull()) << error.data();
   std::string saved_xml = SaveAndReadXml(model);
   EXPECT_THAT(saved_xml, HasSubstr("0.1 1.23 2.345"));
   mj_deleteModel(model);

test/xml/xml_util_test.cc

@@ -1,57 +0,0 @@
-// Copyright 2024 DeepMind Technologies Limited
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include <string>
-#include <vector>
-
-#include <gtest/gtest.h>
-#include <gmock/gmock.h>
-#include "src/xml/xml_util.h"
-#include "test/fixture.h"
-
-namespace mujoco {
-namespace {
-
-using XMLUtilTest = MujocoTest;
-
-using ::testing::ElementsAre;
-
-TEST_F(XMLUtilTest, String2VectorFloat) {
-  std::vector<float> v = mjXUtil::String2Vector<float>(" 1.2 3.2     5.3 6 ");
-  EXPECT_THAT(v, ElementsAre(1.2, 3.2, 5.3, 6));
-}
-
-TEST_F(XMLUtilTest, String2VectorEmpty) {
-  std::vector<float> v = mjXUtil::String2Vector<float>("");
-  EXPECT_THAT(v, ElementsAre());
-}
-
-TEST_F(XMLUtilTest, String2VectorError) {
-  std::vector<float> v = mjXUtil::String2Vector<float>("ABCD. /123/122/113");
-  EXPECT_THAT(v, ElementsAre());
-}
-
-
-TEST_F(XMLUtilTest, String2VectorInt) {
-  std::vector<int> v = mjXUtil::String2Vector<int>(" -1 3 5 6");
-  EXPECT_THAT(v, ElementsAre(-1, 3, 5, 6));
-}
-
-TEST_F(XMLUtilTest, String2VectorString) {
-  auto v = mjXUtil::String2Vector<std::string>(" abc  def ");
-  EXPECT_THAT(v, ElementsAre("abc", "def"));
-}
-
-}  // namespace
-}  // namespace mujoco