From: Wyss Clemens <WYS@...>
Date: 2001-12-11T18:10:31+09:00
Subject: [ruby-talk:28191] RE:  c++2rb


2.) sub!(/(\S+)(\s)*}/, '\1\2; end')
3.) eval("gsub!(/(#{token_re})::\\1(.*)/, 'def initialize\\2')")

'using namespace foo;' -> include foo ?
'using foo::foomember;' -> ?

Clemens

> -----Original Message-----
> From: Issac Trotts [mailto:ITrotts@IdolMinds.com]
> Sent: Dienstag, 11. Dezember 2001 04:25
> To: ruby-talk@ruby-lang.org
> Subject: [ruby-talk:28170] c++2rb
> 
> 
> Here's a little program to partially automate conversion from 
> C++ to Ruby.  
> If you make any improvements, please let me know.
> 
> A few things surprised me about the script:
> 
> 1. When I tried to move the body of the while loop into a 
> separate function
> taking
>    no args, the script suddenly stopped working.  The 
> expressions only use
> $_ so I don't
>    see what the trouble is.  Here's the error message:
> 
> 	c2rb:19:in `gsub!': $_ value need to be String (nil given)
> (TypeError)
> 
>    Isn't $_ supposed to be global?
> 
> 2. See the line that says "WHY DOESN'T THIS WORK?"
> 
> 3. The failed attempt at making a regular expression for 
> constructors (see
> below).
>    I want to match a pattern that looks like FOO::FOO()
> 
> One more question before I go: 
> 	What are the Ruby equivalents of 'using namespace foo;'
> 	and 'using foo::foomember;'?
> 
> 
> 
> ======= %< ========
> 
> #!/usr/bin/env ruby
> #
> # c++2rb : partial conversion from C and C++ to Ruby
> #
> # Copyright (c) 2001 Issac Trotts <itrotts at idolminds dot com>
> #
> # Under the Ruby license 
> #
> # TODO
> # - template functions
> # - template classes
> 
> type_re = '(void|char|short|int|long|float|double)'
> map_re = '\bmap\s*<.*>'
> list_re = '\blist\s*<.*>'
> vector_re = '\bvector\s*<.*>'
> token_re = '[a-zA-Z_][a-zA-Z0-9_]*'
> 
> while gets
>     gsub!(/;/, '')
>     gsub!(/#include\s+\<([^>.]+)(.h)?>/, 'require \'\1\'')
>     gsub!(/const\s*/, '')
>     gsub!(/unsigned\s*/, '')
>     eval('gsub!(/#{list_re}\s*(#{token_re})/, \'\1 = []\')')
>     eval('gsub!(/#{vector_re}\s*(#{token_re})/, \'\1 = []\')')
>     eval('gsub!(/#{map_re}\s*(#{token_re})/, \'\1 = {}\')')
>     gsub!(/push_back/, 'push')
>     gsub!(/std::/, '')
>     gsub!(/cout\s*\<\</, 'puts ')
>     gsub!(/\<\</, '+')
>     gsub!(/this/, 'self')
>     gsub!(/endl/, '"\n"')
>     gsub!(/(public|protected|private)\:/, '\1')
>     # comments
>     gsub!(/\/\//, '#')                             
>     gsub!(/\{/, '')
>     gsub!(/(\s*)}/, '\1end')
>     sub!(/(\S)+(\s)*}/, '\1\2; end') # WHY DOESN'T THIS WORK?
>     gsub!(/case/, 'when')
>     gsub!(/switch/, 'case')
>     gsub!(/default/, 'else')
>     gsub!(/struct/, 'class')
>     gsub!(/virtual\s*/, '')
>     gsub!(/if\s*\(([^)]+)\)/, 'if \1')
>     #gsub!(/if\(([^)]+)\)\s*(\S*)$/, 'if \1; \2')
>     # inheritance
>     gsub!(/:\s+(public|private|protected)/, '<')    
>     gsub!(/\-\>/, '.')
>     # global functions with no args
>     eval("sub!(/#{type_re}\\s+(#{token_re})\\s*\\(\\s*\\)/, "+
>         '\'def \2\')')
>     # global functions with args
>     eval("sub!(/#{type_re}\\s+(#{token_re})\\s*(\\(.*\\))\s*{?/, "+
>          '\'def \2\3\')')
>     # constructors 
>     #eval("gsub!(/#{(token_re)::\$1(.*)/, 'def initialize\2')")
>     # member functions with no args
>     
> eval("sub!(/#{type_re}\\s+(#{token_re})::(#{token_re})\\s*\\(\\s*\\)/,
> "+
>          '\'class \2; def \3 # FIXME: put another end at the end\')') 
>     # member functions with args
>     
> eval("sub!(/#{type_re}\\s+(#{token_re})::(#{token_re})\\s*\\((.*)\\)/,
> "+
>          '\'class \2; def \3 (\4) # FIXME: put another end at 
> the end\')') 
>     # member function invocations with no args
> 
>     # member function invocations with args
> 
>     # for-loops...
> 
>     # using std::cout etc
> 
>     # using namespace X
> 
>     # namespaces
>     gsub!(/namespace/, 'module')
> 
>     print 
> end
>