> The new compiler sounds like a step forward by many measures.  The 
> performance issue needs to be quantified more.  When you say it is slower, 
> is it 5% slower? That would be tolerable.  If it is 20% slower it might 
> not be tolerable.

Running a quick benchmark "[Object compileAll] timeRun" gives:

Old compiler:  1794 1749 1723
New compiler:  4417 4384 4423

So it's about a factor of 2.5 where this might be a little skewed since I 
just loaded the closure compiler (which is a little more complex than the 
non-closure compiling version) and switched between the two. Hm... this is 
significantly more than I expected... and if we actually cut out the time it 
takes for retrieving the source code by, e.g., doing:

code := Object selectors asArray
    collect:[:sel| Object sourceCodeAt: sel].
compiler := Object compilerClass.
[code do:[:src|
    compiler new
        compile: src
        in: Object
        notifying: nil
        ifFail:[]]
] timeToRun.

We're almost precisely at a factor of 3 or so (spending ~50% of the time in 
SmaCCScanner>>next btw).

> If it breaks eToys, I would think you will need to get
> an estimate from them for what is required to deal with this.

Well, the real issue which I'd like to see fixed is error reporting. I have 
found that SmaCC parsers are notoriously bad at it - except from "token not 
expected" it doesn't tell you anything about what is wrong (and it doesn't 
even tell you the token - so if you don't know how the next characters 
compose you are at a total loss). For example, consider the following 
erronous expressions:

            SmaCC                  Squeak
a := .      Token not expected     Expression expected
3 foo: +5   Token not expected     Argument expected
[:foo ^3+4] Token not expected     Vertical bar expected
[^42        Token not expected     Period or right bracket expected


For a newbie this is deeply problematic. It's hard enough to get this stuff 
right even if the compiler tells you what it expects - but if you only know 
that there is "something wrong here" (perhaps a missing \item? ;-))) it's 
almost impossible to find out.

Cheers,
  - Andreas