bison and downwards compatibility

[Joerg Hoffmann]

Dear Bison makers,

First, thanks for your very useful tool. However, I have to say I'm 
frustrated by the utter lack of downwards compatibility. Why is this 
necessary?

I'm working with code that originated in 1998. It has in the meantime 
been copied so often that it is impossible to revise all instances. 
Every time I get a new bison update I get new errors and complaints that 
are totally cryptic and un-understandable, whereas with the older 
versions everything worked. Just as a simple example, some old versions 
allowed to ommit the ";" at the end of a rule. Newer versions don't. In 
effect, I have spent countless hours in the last 5 years inserting ";" 
at the points where some programmer in 1998 happened to leave them away.

It would be so much more convenient if the bison development obeyed some 
form of downwards compatibility.

best regards,
Joerg Hoffmann