1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
|
/* Generated by re2c */
#line 1 "calc_008.re"
// re2c $INPUT -o $OUTPUT -b
/* re2c lesson 001_upn_calculator, calc_008, (c) M. Boerger 2006 - 2007 */
#line 31 "calc_008.re"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define DEBUG(stmt) stmt
int stack[4];
int depth = 0;
int push_num(const char *t, const char *l, int radix)
{
int num = 0;
if (depth >= sizeof(stack))
{
return 3;
}
--t;
while(++t < l)
{
num = num * radix + (*t - '0');
}
DEBUG(printf("Num: %d\n", num));
stack[depth++] = num;
return 0;
}
int stack_add()
{
if (depth < 2) return 4;
--depth;
stack[depth-1] = stack[depth-1] + stack[depth];
DEBUG(printf("+\n"));
return 0;
}
int stack_sub()
{
if (depth < 2) return 4;
--depth;
stack[depth-1] = stack[depth-1] - stack[depth];
DEBUG(printf("+\n"));
return 0;
}
int scan(char *p)
{
char *t;
int res = 0;
while(!res)
{
t = p;
#line 67 "calc_008.c"
{
unsigned char curr;
static const unsigned char yybm[256] = {
0, 0, 0, 0, 0, 0, 0, 0,
0, 64, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
64, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
128, 128, 128, 128, 128, 128, 128, 128,
128, 128, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0
};
curr = (unsigned char)*p;
if (yybm[0+curr] & 64) goto scan3;
if (curr <= ',') {
if (curr <= 0x00) goto scan1;
if (curr == '+') goto scan4;
goto scan2;
} else {
if (curr <= '/') {
if (curr <= '-') goto scan5;
goto scan2;
} else {
if (curr <= '0') goto scan6;
if (curr <= '9') goto scan8;
goto scan2;
}
}
scan1:
++p;
#line 109 "calc_008.re"
{ res = depth == 1 ? 0 : 2; break; }
#line 124 "calc_008.c"
scan2:
++p;
#line 110 "calc_008.re"
{ res = 1; continue; }
#line 129 "calc_008.c"
scan3:
curr = (unsigned char)*++p;
if (yybm[0+curr] & 64) goto scan3;
#line 104 "calc_008.re"
{ continue; }
#line 135 "calc_008.c"
scan4:
++p;
#line 107 "calc_008.re"
{ res = stack_add(); continue; }
#line 140 "calc_008.c"
scan5:
++p;
#line 108 "calc_008.re"
{ res = stack_sub(); continue; }
#line 145 "calc_008.c"
scan6:
curr = (unsigned char)*++p;
if (curr <= '/') goto scan7;
if (curr <= '9') goto scan9;
scan7:
#line 106 "calc_008.re"
{ res = push_num(t, p, 10); continue; }
#line 153 "calc_008.c"
scan8:
curr = (unsigned char)*++p;
if (yybm[0+curr] & 128) goto scan8;
goto scan7;
scan9:
curr = (unsigned char)*++p;
if (curr <= '/') goto scan10;
if (curr <= '9') goto scan9;
scan10:
#line 105 "calc_008.re"
{ res = push_num(t, p, 8); continue; }
#line 165 "calc_008.c"
}
#line 111 "calc_008.re"
}
return res;
}
int main(int argc, char **argv)
{
if (argc > 1)
{
char *inp;
int res = 0, argp = 0, len;
while(!res && ++argp < argc)
{
inp = strdup(argv[argp]);
len = strlen(inp);
if (inp[0] == '\"' && inp[len-1] == '\"')
{
inp[len - 1] = '\0';
++inp;
}
res = scan(inp);
free(inp);
}
switch(res)
{
case 0:
printf("Result: %d\n", stack[0]);
return 0;
case 1:
fprintf(stderr, "Illegal character in input.\n");
return 1;
case 2:
fprintf(stderr, "Premature end of input.\n");
return 2;
case 3:
fprintf(stderr, "Stack overflow.\n");
return 3;
case 4:
fprintf(stderr, "Stack underflow.\n");
return 4;
}
}
else
{
fprintf(stderr, "%s <expr>\n", argv[0]);
return 0;
}
}
|
