switch to coroutine execution model

src/Text.cc

@@ -18,7 +18,7 @@ TextTranscoder::TextTranscoder(const char* to, const char* from)
     : ic(iconv_open(to, from)) {
   if (ic == this->INVALID_IC) {
     string error_str = phosg::string_for_error(errno);
-    throw runtime_error(phosg::string_printf("failed to initialize %s -> %s text converter: %s", from, to, error_str.c_str()));
+    throw runtime_error(std::format("failed to initialize {} -> {} text converter: {}", from, to, error_str));
   }
 }
 
@@ -48,7 +48,7 @@ TextTranscoder::Result TextTranscoder::operator()(
         case EILSEQ: {
           string custom_result = this->on_untranslatable(&src, &src_bytes);
           if (custom_result.empty()) {
-            throw runtime_error(phosg::string_printf("untranslatable character at position 0x%zX", bytes_read));
+            throw runtime_error(std::format("untranslatable character at position 0x{:X}", bytes_read));
           } else if (custom_result.size() <= dest_bytes) {
             memcpy(dest, custom_result.data(), custom_result.size());
             dest = reinterpret_cast<char*>(dest) + custom_result.size();
@@ -59,7 +59,7 @@ TextTranscoder::Result TextTranscoder::operator()(
           break;
         }
         case EINVAL:
-          throw runtime_error(phosg::string_printf("incomplete multibyte sequence at position 0x%zX", bytes_read));
+          throw runtime_error(std::format("incomplete multibyte sequence at position 0x{:X}", bytes_read));
         case E2BIG:
           if (!truncate_oversize_result) {
             throw runtime_error("string does not fit in buffer");
@@ -109,13 +109,13 @@ string TextTranscoder::operator()(const void* src, size_t src_bytes) {
         case EILSEQ: {
           string custom_result = this->on_untranslatable(&src, &src_bytes);
           if (custom_result.empty()) {
-            throw runtime_error(phosg::string_printf("untranslatable character at position %zu", bytes_read));
+            throw runtime_error(std::format("untranslatable character at position {}", bytes_read));
           }
           blocks.emplace_back(std::move(custom_result));
           break;
         }
         case EINVAL:
-          throw runtime_error(phosg::string_printf("incomplete multibyte sequence at position %zu", bytes_read));
+          throw runtime_error(std::format("incomplete multibyte sequence at position {}", bytes_read));
         case E2BIG:
           break;
         default:
@@ -457,7 +457,6 @@ void remove_color(phosg::StringWriter& w, const char* src, size_t max_input_char
     }
     src++;
   }
-  w.put<char>(0);
 }
 
 string remove_color(const string& s) {