oberon.pars [1]

/* Project:  COCKTAIL training
 * Descr:    A simple pocket computer (scanner, parser, evaluator)
 * Kind:     Parser specification (solution)
 * Author:   Prof. Dr. Juergen Vollmer <vollmer@dhbw-karlsruhe.de>
 * $Id: expr.pars.in,v 1.7 2010/04/26 10:53:44 vollmer Exp $
 */

// Exercises:
//  - Add computation of the "Value" Attribute to all grammar rules.
//  - Test division by 0!
//  - Add grammar and evaluation rules to compute "sin()", "cos()", and "tan()"
//    see     man (3) sin
//    Add a grammar and evaluation rule for the constant    "pi"
//  - Add more test sources to test your grammar

SCANNER oberon_scan

PARSER  oberon_pars

GLOBAL {
 # include <stdio.h>
 # include <math.h>
}

PREC LEFT  '~'
     LEFT  '*' '/' 'DIV' 'MOD' '&'
     LEFT  '+' '-' 'OR'
     LEFT  '=' '#' '<' '<=' '>' '>=' 'IN' 'IS'

RULE
root    = all.

identdef = <
    = tok_identifier '*'
    .
> . /* identdef */

qualident = <
    = tok_identifier '.' tok_identifier
    .
    = tok_identifier
    .
> . /* qualident */

expression = <
    = '(' expression ')'
    .
    = expression '=' expression
    .
    = expression '#' expression
    .
    = expression '<' expression
    .
    = expression '<=' expression
    .
    = expression '>' expression
    .
    = expression '>=' expression
    .
    = expression 'IN' expression
    .
    = expression 'IS' expression
    .
    = expression '+' expression
    .
    = expression '-' expression
    .
    = expression 'OR' expression
    .
    = expression '*' expression
    .
    = expression '/' expression
    .
    = expression 'DIV' expression
    .
    = expression 'MOD' expression
    .
    = expression '&' expression
    .
    = number
    .
    = char_const
    .
    = string_const
    .
    = 'NIL'
    .
    = '~' expression
    .
    = set
    .
> . /* expression */

set = <
    = '{' element_ls '}'
    .
> . /* set */

element_ls = <      /* <- Das ist eine sperarierte Liste */
    = /* epsilon */
    .
    element_s = <
        = element
        .
        = element_s ',' element
        .
    > . /* element_s */
>. /* element_ls */

element = <
    = expression
    .
    = expression '..' expression
    .
> . /* element */

number = <
    = int_const
    .
    = real_const
    .
> . /* number */

/****************************************/

all = <
    = int_const
    .
    = real_const
    .
    = char_const
    .
    = string_const
    .
    = identdef
    .
    = qualident
    .
    = expression
    .
> . /* all */

/* Tokens */
int_const:      [Value: long]     {Value := 0;          } .
real_const:     [Value: double]   {Value := 0.0;        } .
char_const:     [Value: char]     {Value := '\0';       } .
string_const:   [Value: tIdent]   {Value := NoIdent;    } .
tok_identifier: [Value: tIdent]   {Value := NoIdent;    } .

/* non-terminal attributes */
MODULE attributes
PROPERTY SYN
DECLARE
END attributes