[antlr-interest] please tell me what does it mean "AST" and what does it doing

[paul taney]

--- qwpetrov <petrov at programist.ru> wrote:
> Hi all! 
> I think this is a  very stupip question "please tell
> me what does it 
> mean "AST" and what does it doing?"

One of the main techniques computer scientists use
for reducing the "burden of complexity" (the babel of
languages) is to divide problems up into logical
parts.  In the case of language translation or
compilation they employ this "divide and conquer" 
pattern by translating first into an "intermediate
representation" and then once again to the chip's
language (or "virtual machine").  ASTs are a family
of intermediate "tree languages" that are used for
this purpose.  They vaguely resemble lisp, a
language with "Lots of Silly Parentheses" which 
make it friendly to the machine, less friendly 
to human readers.

If you are interested to the tune of $15, Amazon
has a deal for you:  Terrence Parr's out-of-print
book "Language Translation Using PCCTS & C++" is
there used (3 copies).  For $60 new, I recommend
"Modern Compiler Implementation in [C|Java|ML]" by 
Andrew Appel.  Three books, same material in each.

Mr. Parr's current doc on antlr (which was PCCTS) is 
freely distributed with the antlr package.  Or read 
his course materials from a recent university course 
at

http://www.cs.usfca.edu/~parrt/course/652/index.html

Yours,
paul




__________________________________
Do you Yahoo!?
SBC Yahoo! DSL - Now only $29.95 per month!
http://sbc.yahoo.com

 

Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/