These features are experimental. More user feedback will help to
stabilize them.
+** Multiple %define's for any variable is now an error not a warning.
+
** %define can now be invoked via the command line.
Each of these command-line options
about a missing semicolon where it did not before. Future releases of
Bison will cease to append semicolons entirely.
+** Character literals not of length one.
+
+ Previously, Bison quietly converted all character literals to length
+ one. For example, without warning, Bison interpreted the operators in
+ the following grammar to be the same token:
+
+ exp: exp '++'
+ | exp '+' exp
+ ;
+
+ Bison now warns when a character literal is not of length one. In
+ some future release, Bison will report an error instead.
+
* Changes in version 2.4.2 (????-??-??):
+** Detection of GNU M4 1.4.6 or newer during configure is improved.
+
** %code is now a permanent feature.
A traditional Yacc prologue directive is written in the form: