The Co-Founder of Typesafe, Paul Phillips, hates Scala too. Working on the compiler seems to have driven him mad (he says this, not me, but I don't disagree based on this performance.)
We have computers that are thousands of times faster than the 1980's but Turbo Pascal, then, could compile tens of thousands of lines per second on that hardware. Scala is so complicated it takes minutes to compile large code bases.
Anyone remember what the claims were for Turbo Pascal?
According to Embarcadero Turbo Pascal memorial page, Turbo Pascal 5.5 was compiling 34,000 lines/minute!
http://edn.embarcadero.com/article/20803
Having been introduced to Turbo Pascal line of compilers, spoiled my expectations in regard to C and C++ when I got to learn them afterwards. :)
The textual representation of CL code IS the AST. You can change it to be whatever you want. You can programmatically manipulate the code objects represented by that tree using the same forms and idioms you use on plain old data. There's very little magic that happens "under the hood."
I can't even imagine how awesome the CL ecosystem could be with someone like Paul on its side. sigh
I've been putting in some time to learn Scala but he elucidates much of what bugs me about the language in this talk. I'm hoping to see a, "Good Parts" book but I'm not sure if that's a good sign.