Number literals (Was: Re: Case Range Statement ..)

[Walter Bright]

Leandro Lucarella wrote:
> That's not a good enough reason. Having *one* front-end
> (lexer/parser/semantic analizer) is not good enough. D was supposed to
> make this easy to encourage different implementations. If the D specs are
> twisted and making a new lexer is... confusing, I think that's a failure.

It's 8 lines of code in the lexer to distinguish an octal literal from a 
non-octal one. I don't see a pressing case for disastrous complexity. 
Here they are:

                     case '0': case '1': case '2': case '3':
                     case '4': case '5': case '6': case '7':
                         state = STATE_octal;
                         break;

                     case '_':
                         state = STATE_octal;
                         p++;
                         continue;

D integer literals are identical to C ones, with the addition of _ and 
the elidation of trailing l. It's hard for me to see how this, which has 
been around 30 years in practice and 20 years as a standard, is an 
understandability problem in practice or specification.