/*
 AnaGram Programming Examples
 FC4B: Multiple Fahrenheit-Celsius conversion with signed numbers,
 floating point arithmetic, optional white space, and Kelvin
 temperature input.

 This grammar resolves the conflicts found in FC4.


 Copyright 1993 Parsifal Software. All Rights Reserved.

 This software is provided 'as-is', without any express or implied
 warranty.  In no event will the authors be held liable for any damages
 arising from the use of this software.

 Permission is granted to anyone to use this software for any purpose,
 including commercial applications, and to alter it and redistribute it
 freely, subject to the following restrictions:

 1. The origin of this software must not be misrepresented; you must not
    claim that you wrote the original software. If you use this software
    in a product, an acknowledgment in the product documentation would be
    appreciated but is not required.
 2. Altered source versions must be plainly marked as such, and must not be
    misrepresented as being the original software.
 3. This notice may not be removed or altered from any source distribution.
*/

[
  test file mask = "*.fc4"                                        // C1
  traditional engine  /* turn this off for production use */      // C2
  default token type = double                                     // C3
  disregard white space                                           // C4
  lexeme {unsigned number, end of line}                           // C5
]

eof = -1

(void) grammar
 -> [temperature?, end of line]..., eof                           // P1

(void) temperature
 -> number:c, 'c' + 'C' ={                                        /* P2 */
                   double f = 9*c/5 + 32;
                   printf("%.6g\370F = %.6g\370C = %.6g\370K\n",f,c,c+273.16);
                 }
 -> number:f, 'f' + 'F' = {                                       /* P3 */
                   double c = 5*(f-32)/9;
                   printf("%.6g\370F = %.6g\370C = %.6g\370K\n",f,c,c+273.16);
                 }
 -> '+'?, unsigned number:k, 'k' + 'K' ={                         /* P3a */
                   double c = k - 273.16;
                   double f = 9*c/5 + 32;
                   printf("%.6g\370F = %.6g\370C = %.6g\370K\n", f, c, k);
                 }
 -> error                                                         // P4

number
 -> '-', unsigned number:n        =-n;                            // P5
 -> '+'?, unsigned number:n       =n;                             // P6

unsigned number
 -> integer, '.'?                                                 // P6a
 -> integer:i, '.', fraction:f    =i+f;                           // P6b
 -> '.', fraction:f               =f;                             // P6c

integer
 -> '0-9':d                       =d-'0';                         // P7
 -> integer:n, '0-9':d            =10*n+d-'0';                    // P8

fraction
 -> '0-9':d                       =(d-'0')/10.;                   // P9
 -> '0-9':d, fraction:f           =(d-'0' + f)/10.;               // P10

white space
 -> ' ' + '\t'                                                    // P11
 -> "/*", ~eof?..., "*/"                                          // P12

end of line
 -> ["//", ~(eof + '\n')?...], '\n'                               // P13