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Import AnaGram (near-)release tree into Mercurial.
author David A. Holland
date Sat, 22 Dec 2007 17:52:45 -0500
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-1:000000000000 0:13d2b8934445
1 /*
2 AnaGram Programming Examples
3 FC5: Multiple Fahrenheit-Celsius conversion with signed numbers,
4 floating point arithmetic, optional white space, and Kelvin
5 temperature input.
6
7 This grammar resolves the conflicts found in FC4.
8 Event driven version of FC4B.
9
10
11 Copyright 1993 Parsifal Software. All Rights Reserved.
12
13 This software is provided 'as-is', without any express or implied
14 warranty. In no event will the authors be held liable for any damages
15 arising from the use of this software.
16
17 Permission is granted to anyone to use this software for any purpose,
18 including commercial applications, and to alter it and redistribute it
19 freely, subject to the following restrictions:
20
21 1. The origin of this software must not be misrepresented; you must not
22 claim that you wrote the original software. If you use this software
23 in a product, an acknowledgment in the product documentation would be
24 appreciated but is not required.
25 2. Altered source versions must be plainly marked as such, and must not be
26 misrepresented as being the original software.
27 3. This notice may not be removed or altered from any source distribution.
28 */
29
30 [
31 test file mask = "*.fc4" // C1
32 traditional engine /* turn this off for production use */ // C2
33 default token type = double // C3
34 disregard white space // C4
35 lexeme {unsigned number, end of line} // C5
36 event driven // C6
37 ]
38
39 eof = -1
40
41 (void) grammar
42 -> [temperature?, end of line]..., eof // P1
43
44 (void) temperature
45 -> number:c, 'c' + 'C' ={ /* P2 */
46 double f = 9*c/5 + 32;
47 printf("%.6g\370F = %.6g\370C = %.6g\370K\n",f,c,c+zero);
48 }
49 -> number:f, 'f' + 'F' ={ /* P3 */
50 double c = 5*(f-32)/9;
51 printf("%.6g\370F = %.6g\370C = %.6g\370K\n",f,c,c+zero);
52 }
53 -> '+'?, unsigned number:k, 'k' + 'K' ={ /* P3a */
54 double c = k - zero;
55 double f = 9*c/5 + 32;
56 printf("%.6g\370F = %.6g\370C = %.6g\370K\n", f, c, k);
57 }
58 -> error // P4
59
60 number
61 -> '-', unsigned number:n =-n; // P5
62 -> '+'?, unsigned number:n =n; // P6
63
64 unsigned number
65 -> integer, '.'? // P6a
66 -> integer:i, '.', fraction:f =i+f; // P6b
67 -> '.', fraction:f =f; // P6c
68
69 integer
70 -> '0-9':d =d-'0'; // P7
71 -> integer:n, '0-9':d =10*n+d-'0'; // P8
72
73 fraction
74 -> '0-9':d =(d-'0')/10.; // P9
75 -> '0-9':d, fraction:f =(d-'0' + f)/10.; // P10
76
77 white space
78 -> ' ' + '\t' // P11
79 -> "/*", ~eof?..., "*/" // P12
80
81 end of line
82 -> ["//", ~(eof + '\n')?...], '\n' // P13
83
84 { /* Embedded C */
85
86 #include <stdlib.h>
87 #include <stdio.h>
88
89 const double zero = 273.16;
90
91 int main(void) {
92 init_fc5(); /* Initialize parser */
93 while (fc5_pcb.exit_flag == AG_RUNNING_CODE) { /* Until done */
94 fc5_pcb.input_code = getchar(); /* Hand char to parser */
95 fc5(); /* Process character */
96 }
97 return (fc5_pcb.exit_flag - AG_SUCCESS_CODE); /* Return error level */
98 }
99
100 } // End of Embedded C