commit dd111936fcac3a34a41a1d2fe163132dcca7c3c4
Author: Daniel Swanson <popcorn.tomato.dude@gmail.com>
Date:   Sat Jun 5 19:21:02 2021 -0500

    helper functions for use in apertium

diff --git a/lttoolbox/input_file.cc b/lttoolbox/input_file.cc
index 6818aa3..51c9b11 100644
--- a/lttoolbox/input_file.cc
+++ b/lttoolbox/input_file.cc
@@ -20,6 +20,7 @@
 #include <stdexcept>
 #include <unicode/ustdio.h>
 #include <cstring>
+#include <iostream>
 
 InputFile::InputFile()
   : infile(stdin), buffer_size(0)
@@ -42,6 +43,15 @@ InputFile::open(const char* fname)
   return (infile != nullptr);
 }
 
+void
+InputFile::open_or_exit(const char* fname)
+{
+  if (!open(fname)) {
+    std::cerr << "Error: Unable to open '" << fname << "' for reading." << std::endl;
+    exit(EXIT_FAILURE);
+  }
+}
+
 void
 InputFile::close()
 {
diff --git a/lttoolbox/input_file.h b/lttoolbox/input_file.h
index dadb09b..7a8aad7 100644
--- a/lttoolbox/input_file.h
+++ b/lttoolbox/input_file.h
@@ -33,6 +33,7 @@ public:
   InputFile();
   ~InputFile();
   bool open(const char* fname = nullptr);
+  void open_or_exit(const char* fname = nullptr);
   void close();
   UChar32 get();
   UChar32 peek();
diff --git a/lttoolbox/ustring.cc b/lttoolbox/ustring.cc
index b537a78..9bdfd24 100644
--- a/lttoolbox/ustring.cc
+++ b/lttoolbox/ustring.cc
@@ -63,6 +63,16 @@ to_ustring(const char* s)
   return ret;
 }
 
+UString
+to_ustring(char* s)
+{
+  auto sz = strlen(s);
+  UString ret;
+  ret.reserve(sz);
+  utf8::utf8to16(s, s+sz, std::back_inserter(ret));
+  return ret;
+}
+
 void
 ustring_to_vec32(const UString& str, std::vector<int32_t>& vec)
 {
diff --git a/lttoolbox/ustring.h b/lttoolbox/ustring.h
index da4b3f6..c181e98 100644
--- a/lttoolbox/ustring.h
+++ b/lttoolbox/ustring.h
@@ -37,6 +37,9 @@ double stod(const UString& str);
 // for command-line arguments
 UString to_ustring(const char* str);
 
+// for XML
+UString to_ustring(char* str);
+
 // append UTF-16 string to UTF-32 vector of symbols
 void ustring_to_vec32(const UString& str, std::vector<int32_t>& vec);