;; -*- Hen -*-
;;
;;  A grammar for I-expressions
;;
;;  Copyright 2010-2011 Ivan Raikov and the Okinawa Institute of
;;  Science and Technology.
;;
;;  This program is free software: you can redistribute it and/or
;;  modify it under the terms of the GNU General Public License as
;;  published by the Free Software Foundation, either version 3 of the
;;  License, or (at your option) any later version.
;;
;;  This program is distributed in the hope that it will be useful, but
;;  WITHOUT ANY WARRANTY; without even the implied warranty of
;;  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;;  General Public License for more details.
;;
;;  A full copy of the GPL license can be found at
;;  <http://www.gnu.org/licenses/>.
;;

(require-extension lalr )

(define expr-parser
  (lalr-parser

   (output: parser "iexpr.grm.scm")

   (out-table: "iexpr.grm.out")

   ;; --- token definitions

   ( 
    END 
    (left: SPACE WORD NAT REAL COMMA RPAREN )
    (right: LPAREN BREAK)
    )

   ;; Toplevel entry point 

   (stream
    ()                 : (Empty)
    (block)            : $1
    (stream END)       : $1
    (stream BREAK)     : $1
    (stream END block) : (tree-add-sibling $1 $3))

   (block
    (block0) : (final-line-tree $1)
    (BREAK block) : $2)
   
   (block0
    (line)          :    (initial-line-tree $1)
    (block0 line)   :    (tree-insert-line $2 $1)
    )
   
   (line
    (list)               : (make-line 0 $1)
    (SPACE list)         : (make-line $1 $2)
    (line BREAK)         : $1
    )

   (group
    (LPAREN RPAREN)                        : `()
    (LPAREN list RPAREN)                   :  $2
    (LPAREN listsep list RPAREN)           :  $3
    )

   (list
    (list0) : (reverse $1))

   (list0
    (listelem)                         : (list $1)
    (list0 listsep listelem)           : (cons $3 $1)
    (list0 listsep)                    : $1
    )

   (listsep
    (SPACE)
    (COMMA)
    (listsep listsep))

   (listelem
    (scalar) : $1
    (group)  : $1)


   (scalar
    (WORD) : $1
    (NAT)  :  $1
    (REAL)  : $1)

))