What's better about Ruby than Python?

Roy Smith roy at panix.com
Tue Aug 19 14:45:19 CEST 2003


Alex Martelli <aleaxit at yahoo.com> wrote:
> They may not change the "underlying" language but they sure allow anybody
> to change the language that is actually IN USE.  That is definitely NOT
> what I want in a language for writing production-level applications.

Here's a real-life example of how macros change the language.  Some C++ 
code that I'm working with now, has a debug macro that is used like this:

   DEBUG (cout << "I'm a debug statement\n";)

Note the semicolon inside the closing paren.

I write in emacs, and depend heavily on its knowlege of C++ syntax to 
auto-indent.  It's not just a convenience, it's an interactive typo 
prevention tool (if the code doesn't indent the way I expect, it's 
probably because I messed up the punctuation).  I'm personally not a big 
fan of syntax coloring, but many people are, for much the same reason.

The problem is, emacs doesn't know what to do with the code above.  It 
doesn't see a trailing semicolon, so (IIRC), it tries to indent the next 
line another step, as if it were a continuation of the same statement.  
What a pain.  Eventually, I figured out I could "solve" the problem by 
adding an extra semicolon at the end:

   DEBUG (cout << "I'm a debug statement\n";);

It looks ugly, but at least it indents correctly.

Before you start ranting about emacs, note that there are lots of 
language-aware editors (and other tools), all of which would suffer from 
the same problem.  The macro has essentially invented new syntax, which 
the tool can't possibly know about.




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