Move UTF-8 code inside class

parser.cpp

@@ -1,5 +1,6 @@
 #include <assert.h>
 #include <typeinfo>
+#include <langinfo.h>
 
 #include "parser.hpp"
 
@@ -34,3 +35,59 @@ std::vector<Parser::Action *> Parser::Parser::input( wchar_t ch )
 
   return ret;
 }
+
+Parser::UTF8Parser::UTF8Parser()
+  : parser(), buf_len( 0 )
+{
+  if ( strcmp( nl_langinfo( CODESET ), "UTF-8" ) != 0 ) {
+    fprintf( stderr, "rtm requires a UTF-8 locale.\n" );
+    throw std::string( "rtm requires a UTF-8 locale." );
+  }
+}
+
+std::vector<Parser::Action *> Parser::UTF8Parser::input( char c )
+{
+  assert( buf_len < BUF_SIZE );
+
+  buf[ buf_len++ ] = c;
+
+  /* This function will only work in a UTF-8 locale. */
+  /* This must be asserted by other code. */
+
+  wchar_t pwc;
+  mbstate_t ps;
+  memset( &ps, 0, sizeof( ps ) );
+
+  size_t bytes_parsed = mbrtowc( &pwc, buf, buf_len, &ps );
+
+  /* this returns 0 when n = 0! */
+
+  /* This function annoying returns a size_t so we have to check
+     the negative values first before the "> 0" branch */
+
+  if ( bytes_parsed == 0 ) {
+    /* character was NUL, accept and clear buffer */
+    assert( buf_len == 1 );
+    buf_len = 0;
+    pwc = L'\0';
+  } else if ( bytes_parsed == (size_t) -1 ) {
+    /* invalid sequence, use replacement character and clear buffer */
+    assert( errno == EILSEQ );
+    buf_len = 0;
+    pwc = (wchar_t) 0xFFFD;
+  } else if ( bytes_parsed == (size_t) -2 ) {
+    /* can't parse complete multibyte character */
+    /* return empty vector */
+    std::vector<Action *> vec;
+    return vec;
+  } else if ( bytes_parsed > 0 ) {
+    /* parsed into pwc, accept and clear buffer */
+    assert( bytes_parsed == buf_len );
+    buf_len = 0;
+  } else {
+    throw std::string( "Unknown return value from mbrtowc" );
+  }
+
+  /* we parsed character into pwc */
+  return parser.input( pwc );
+}