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comparison examples/ffcalc/ffcalcx.syn @ 0:13d2b8934445

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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 {/* FOUR FUNCTION CALCULATOR: FFCALCX.SYN */}
2
3 // -- CONFIGURATION SECTION ----------------------------
4 [
5 default token type = double
6 disregard white space
7 lexeme { real}
8 left { '+', '-'}
9 left { '*', '/'}
10 right {unary minus}
11 ]
12
13 // -- FOUR FUNCTION CALCULATOR -------------------------
14 (void) calculator $
15 -> [calculation?, '\n']..., eof
16
17 (void) calculation
18 -> expression:x =printf("%g\n",x);
19 -> name:n, '=', expression:x ={
20 printf("%c = %g\n",n+'A',value[n]=x);}
21 -> error
22
23 expression
24 -> name:n = value[n];
25 -> real
26 -> '(', expression:x, ')' = x;
27 -> expression:x, '+', expression:t = x+t;
28 -> expression:x, '-', expression:t = x-t;
29 -> expression:t, '*', expression:f = t*f;
30 -> expression:t, '/', expression:f = t/f;
31 -> unary minus, expression:f = -f;
32
33 // -- LEXICAL UNITS ------------------------------------
34 digit = '0-9'
35 eof = -1
36 unary minus = '-'
37
38 (void) white space
39 -> ' ' + '\t' + '\r' + '\f' + '\v'
40 -> "/*", ~eof?..., "*/"
41
42 (int) name
43 -> 'a-z' + 'A-Z':c = c-'A';
44
45 real
46 -> integer part:i, '.', fraction part:f = i+f;
47 -> integer part, '.'?
48 -> '.', fraction part:f = f;
49
50 integer part
51 -> digit:d = d-'0';
52 -> integer part:x, digit:d = 10*x + d-'0';
53
54 fraction part
55 -> digit:d =(d-'0')/10.;
56 -> digit:d, fraction part:f =(d-'0' + f)/10.;
57
58 { /* -- EMBEDDED C ---------------------------------- */
59 double value[64]; /* registers */
60 int main(void) {
61 ffcalcx();
62 return 0;
63 }
64 } /* -- END OF EMBEDDED C ----------------------------*/