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Date: Fri, 17 Oct 2003 17:46:31 -0400
From: Andrew Lenharth <andrewl@debian.org>
To: caml-list@inria.fr
Subject: [Caml-list] a patch to support + and * in ocamlyacc
Message-ID: <20031017214631.GA6576@peuter>
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I find myself having to often implement rules such as:

foo_plus: foo {[$1]} | foo foo_plus {$1::$2} ;
foo_star: foo_plus {$1} | {[]} ;

in my parsers.  To get rid of this annoyance, here 
is a patch that add support for * and + to ocamlyacc.

http://vilya.homelinux.net/~andrewl/ocamlyacc_p1.diff

it is a bit hackish, but even limited support for * and + makes
writting grammers less painful.

I modify get_name to check for + and *, and rewrite the name
it finds if those exist.  It also adds appropriate rules to a 
buffer to implement the rewritten name.  I change the read character
rutine such that at EOF I switch to the buffer holding the generated
rules.  This has been tested not to break the bootstrapping system.

An example:

%token <int> INT_LITERAL
%token EOF

%start main /* entry point */
%type <int list> main

%%
main:
  INT_LITERAL+ EOF {$1}
  ;


Andrew Lenharth

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