Correctly unescape/escape string in USDA parser/pprinter.

src/ascii-parser.cc

@@ -1384,6 +1384,24 @@ bool AsciiParser::MaybeString(value::StringData *str) {
       return false;
     }
 
+    if (c == '\\') {
+      // escaped quote? \" \'
+      char nc;
+      if (!LookChar1(&nc)) {
+        return false;
+      }
+
+      if (nc == '\'') {
+        ss << "'";
+        _sr->seek_from_current(1); // advance 1 char
+        continue;
+      } else if (nc == '"') {
+        ss << "\"";
+        _sr->seek_from_current(1); // advance 1 char
+        continue;
+      }
+    }
+
     if (single_quote) {
       if (c == '\'') {
         end_with_quotation = true;
@@ -1457,7 +1475,7 @@ bool AsciiParser::MaybeTripleQuotedString(value::StringData *str) {
   int single_quote_count = 0;  // '
   int double_quote_count = 0;  // "
 
-  bool got_triple_quote{false};
+  bool got_closing_triple_quote{false};
 
   while (!Eof()) {
     char c;
@@ -1470,6 +1488,7 @@ bool AsciiParser::MaybeTripleQuotedString(value::StringData *str) {
     // Seek \""" or \'''
     // Unescape '\'
     if (c == '\\') {
+#if 0
       if (single_quote) {
         std::vector<char> buf(3, '\0');
         if (!LookCharN(3, &buf)) {
@@ -1503,6 +1522,31 @@ bool AsciiParser::MaybeTripleQuotedString(value::StringData *str) {
           continue;
         }
       }
+#else
+      std::vector<char> buf(3, '\0');
+      if (!LookCharN(3, &buf)) {
+        // at least 3 chars should be read
+        return false;
+      }
+
+      if (buf[0] == '\'' &&
+          buf[1] == '\'' &&
+          buf[2] == '\'') {
+        str_buf << "'''";
+        // advance
+        _sr->seek_from_current(3);
+        locinfo.col += 3;
+        continue;
+      } else if (buf[0] == '"' &&
+            buf[1] == '"' &&
+            buf[2] == '"') {
+          str_buf << "\"\"\"";
+          // advance
+          _sr->seek_from_current(3);
+          locinfo.col += 3;
+          continue;
+      }
+#endif
     }
 
     str_buf << c;
@@ -1552,17 +1596,25 @@ bool AsciiParser::MaybeTripleQuotedString(value::StringData *str) {
 
     if (double_quote_count == 3) {
       // got '"""'
-      got_triple_quote = true;
-      break;
+      if (single_quote) {
+        // continue
+      } else {
+        got_closing_triple_quote = true;
+        break;
+      }
     }
     if (single_quote_count == 3) {
       // got '''
-      got_triple_quote = true;
-      break;
+      if (double_quote_count) {
+        // continue
+      } else {
+        got_closing_triple_quote = true;
+        break;
+      }
     }
   }
 
-  if (!got_triple_quote) {
+  if (!got_closing_triple_quote) {
     SeekTo(loc);
     return false;
   }
@@ -1578,7 +1630,12 @@ bool AsciiParser::MaybeTripleQuotedString(value::StringData *str) {
     s.erase(s.size() - 3);
   }
 
+  DCOUT("str = " << s);
+
   str->value = unescapeControlSequence(s);
+
+  DCOUT("unescape str = " << str->value);
+
   str->line_col = start_cursor.col;
   str->line_row = start_cursor.row;
   str->is_triple_quoted = true;
@@ -4898,7 +4955,7 @@ bool ParseUnregistredValue(const std::string &_typeName, const std::string &str,
   }
 
   bool array_qual = false;
-  std::string typeName = _typeName; 
+  std::string typeName = _typeName;
   if (endsWith(typeName, "[]")) {
     typeName = removeSuffix(typeName, "[]");
     array_qual = true;
@@ -4911,7 +4968,7 @@ bool ParseUnregistredValue(const std::string &_typeName, const std::string &str,
       (*err) += "Unsupported type: " + typeName + "\n";
     }
     return false;
-  } 
+  }
 
   tinyusdz::StreamReader sr(reinterpret_cast<const uint8_t *>(str.data()), str.size(), /* swap endian */ false);
   tinyusdz::ascii::AsciiParser parser(&sr);
@@ -4949,8 +5006,8 @@ bool ParseUnregistredValue(const std::string &_typeName, const std::string &str,
   default: {
     if (err) {
       (*err) = fmt::format("Unsupported or unimplemeneted type `{}`", typeName);
-    } 
-    return false; 
+    }
+    return false;
   }
   }
 

src/str-util.cc

@@ -81,6 +81,7 @@ std::string escapeControlSequence(const std::string &str) {
   std::string s;
 
   for (size_t i = 0; i < str.size(); i++) {
+
     if (str[i] == '\a') {
       s += "\\x07";
     } else if (str[i] == '\b') {
@@ -92,7 +93,16 @@ std::string escapeControlSequence(const std::string &str) {
     } else if (str[i] == '\f') {
       s += "\\x0c";
     } else if (str[i] == '\\') {
-      s += "\\\\";
+      // skip escaping backshash for escaped quote string: \' \"
+      if (i + 1 < str.size()) {
+        if ((str[i+1] == '"') || (str[i+1] == '\'')) {
+          s += str[i];
+        } else {
+          s += "\\\\";
+        }
+      } else {
+        s += "\\\\";
+      }
     } else {
       s += str[i];
     }

src/value-pprint.cc

@@ -810,7 +810,7 @@ std::string pprint_value(const value::Value &v, const uint32_t indent,
     case TypeTraits<value::token>::type_id(): {
       auto p = v.as<value::token>();
       if (p) {
-        os << quote(p->str());
+        os << buildEscapedAndQuotedStringForUSDA(p->str());
       } else {
         os << "[InternalError: Token type TypeId mismatch.]";
       }
@@ -821,7 +821,7 @@ std::string pprint_value(const value::Value &v, const uint32_t indent,
       if (p) {
         std::vector<std::string> vs;
         std::transform(p->begin(), p->end(), std::back_inserter(vs),
-                       [](const value::token &tok) { return tok.str(); });
+                       [](const value::token &tok) { return buildEscapedAndQuotedStringForUSDA(tok.str()); });
 
         os << quote(vs);
       } else {

tests/usda/string-escape-006.usda

@@ -0,0 +1,4 @@
+#usda 1.0
+(
+  "bor\"a"
+)

tests/usda/triple-quoted-string-003.usda

@@ -0,0 +1,7 @@
+#usda 1.0
+
+def "bora" {
+  string copyrights = '''Copyright ©
+\''' \"""
+'''
+}