How to implement optional semicolon rules

[Matthias Simon]

Hi,

I am struggling with some semicolon rules for some time now. In this 
language (TTCN3) statements end with an mandatory semicolon, except 
there is a curly bracket around. Example:

// -------------8<-------------[SNIP!]
    {
        var integer a;
        var integer b[2] := { 23, 5 }
        var integer c
    }
// ------------->8-------------[SNAP!]


Declaration for variable b does not require a terminating semicolon, 
due to closing bracket of its initialization. Also declaration of 
variable c needs no semicolon due to the closing block.

TTCN3's grammar is already quite complex, therefore I made semicolon 
_always_ mandatory and patched the lexer to `inject' semicolons when 
they were expected by bison. This turned out to be quite hacky, so I am 
a little clueless here. Perhaps you have some ideas how to solve this 
nicely?

Cheers!

Matthias