[ILUG] bind + lex + yacc...

[Brian Foster]

  | Date: Tue, 23 Jul 2002 09:44:28 +0200
  | From: David Neary <dneary at wanadoo.fr>
  | 
  | Paul Jakma wrote:
  | > >  Personally, I think they are demented. It's much more a job for
  | > > something simple like Sed or Awk.
  | > 
  | > ah.. no. sed - you'll only substitute stuff, not powerful enough.
  | > awk doesnt have the data structures. i've looked.
  | 
  | You can only substitute stuff in sed?  As someone who uses it quite
  | a bit for other stuff, because I'm lazy, I'd have to disagree.

 the "awk doesn't have data structures" is not exactly correct
 either, albeit like the sed(1) claim, it's not entirely wrong
 either (making a distinction between common usage and what is
 actually possible / done by some).

 awk(1) --- esp. the new awk, `nawk' ("new" is a relative term
 as `nawk' is c.15(?) years old by now, and most `awk's are of
 the "new" form, including GNU awk, gawk(1)) --- can structure
 data, albeit in a slightly sideways form:  associative arrays
 (esp. multi-dimensional arrays).

 e.g., a C/C++ like data structure:

    struct Foo {
        int   a;
        int   b;
        char* s;
    } key;

 can be approximated in several ways.  one possibility is:

    Foo[key,"a"]     # struct Foo key;  key.a ...
    Foo[key,"b"]     # struct Foo key;  key.b ...
    ...

 another is:

    key["Foo","a"]   # struct Foo key;  key.a ...

 another is:

    Foo[key] = a SUBSEP b SUBSEP s

 and there are yet other variations.  season as to taste.

 it is the new awk which is described in a classic reference
 which should be on everyone's bookshelf:

    Alfred V Aho, Brian W Kernighan, and Peter J Weinberger,
    «The AWK Programming Lanuguage»,
    1988, Addison-Wesley, ISBN 0-201-07981-X.

 you should recognize the authors of the book as being the
 `A', `K', and `W' of `awk' ....

cheers!
	-blf-
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