"ParseTree is a little brown stinky ferret that digs down a hole and violently rips the AST away from the warm bosom of ruby."
MetaRuby: February 2005 Archives
drbrain (9:42): my machine just did factorial of 5!
zenspider (9:42): yay!
drbrain (9:43): it takes just under 1 second to pull the ParseTree of demo/factorial.rb all the way out to a result
zenspider (9:44): are you shitting me???
ONE SECOND?
drbrain (9:45): $ time ruby run.rb demo/factorial.rb
Machine Stack: [120]
Call Stack: #<Stack:0x31c6ec @sp=0, @fp=0, @stack=[:stack_empty, 3, 120, :stack_empty, :stack_empty, :stack_empty, :stack_empty, 79, 120, :stack_empty, :stack_empty, :stack_empty, :stack_empty, 22, 120, :stack_empty, :stack_empty, :stack_empty, :stack_empty]>
Returned: 120
real 0m1.053s
user 0m0.810s
sys 0m0.040s
drbrain (9:45): now I need to get it simplified down enough to run through ruby2c
*sweat*sweat*sweat*
After far too long, I finally have the dubious honor of releasing ruby2c 1.0.0 beta 1 today. I'm itching to do it, we really need to get it out there so people can get their eyes on it and give us feedback. I'm also nervous as hell... the thing is a mess!
Understand what we mean by beta. It means we need eyes on it, it means it was ready enough to put out in the wild, but it also means that it isn't ready for any real use.
What can it do?
Well, currently it can pass all of its unit tests (325 tests with 512 assertions) and it can translate nice simple static algorithmic code into C without much problem. For example:
& cat x.rb class Something def blah; return 2+2; end def main; return blah; end end & ./translate.rb x.rb > x.c & gcc -I /usr/local/lib/ruby/1.8/powerpc-darwin x.c x.c: In function `main': x.c:17: warning: return type of `main' is not `int' & ./a.out & echo $? 4
What can it not do?
More than it can.
It can't (and won't) translate dynamic code. Period. That is simply not the intent.
It probably can't translate a lot of static code that we simply haven't come across or anticipated yet. Our tests cover a fair amount, our validation runs cover a lot more than that, but it is still fairly idiomatic ruby and that puts us at being better at certain styles of coding and much worse at others.
It is also simply rough around the edges. We've rounded out the rdoc but haven't done a thing for general documentation yet. These are on our list, and rather high on our priority list, but we just haven't had the time yet. For now, check out the rdoc and the PDF presentation that we've had up for a while.
PLEASE: file bugs! We need feedback and we'd like to be able to track it. The ruby2c project is on rubyforge and I'm getting the trackers set up today as well.
I am releasing ParseTree 1.3.3 today in preparation of our ruby2c release (also today). Changes in ParseTree are minor, but necessary for ruby2c.
ParseTree is a C extension (using RubyInline) that extracts the parse tree for an entire class or a specific method and returns it as a s-expression (aka sexp) using ruby's arrays, strings, symbols, and integers.
As an example:
def conditional1(arg1)
if arg1 == 0 then
return 1
end
return 0
end
becomes:
[:defn,
:conditional1,
[:scope,
[:block,
[:args, :arg1],
[:if,
[:call, [:lvar, :arg1], :==, [:array, [:lit, 0]]],
[:return, [:lit, 1]],
nil],
[:return, [:lit, 0]]]]]
Features/Problems:
- Uses RubyInline, so it just drops in.
- Includes SexpProcessor and CompositeSexpProcessor.
- Allows you to write very clean filters.
- Includes show.rb, which lets you quickly snoop code.
- Includes abc.rb, which lets you get abc metrics on code.
- abc metrics = numbers of assignments, branches, and calls.
- whitespace independent metric for method complexity.
- Only works on methods in classes/modules, not arbitrary code.
- Does not work on the core classes, as they are not ruby (yet).
Changes:
- 3 minor enhancement
- Cleaned up parse_tree_abc output
- Patched up null class names (delegate classes are weird!)
- Added UnknownNodeError and switched SyntaxError over to it.
- 2 bug fixes
- Fixed BEGIN node handling to recurse instead of going flat.
- FINALLY fixed the weird compiler errors seen on some versions of gcc 3 .4.x related to type punned pointers.
