4 |
#include <stdlib.h> |
#include <stdlib.h> |
5 |
/* NULL */ |
/* NULL */ |
6 |
#include <stddef.h> |
#include <stddef.h> |
7 |
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/* dlopen, dlsym, dlerror */ |
8 |
#include <dlfcn.h> |
#include <dlfcn.h> |
9 |
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/* assert */ |
10 |
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#include <assert.h> |
11 |
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|
12 |
#define HASHTBLSIZE 65536 |
#define HASHTBLSIZE 65536 |
13 |
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|
14 |
typedef struct stack_item |
typedef struct stack_item |
15 |
{ |
{ |
16 |
enum {value, string, ref, func} type; |
enum { |
17 |
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value, /* Integer */ |
18 |
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string, |
19 |
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ref, /* Reference (to an element in the |
20 |
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hash table) */ |
21 |
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func, /* Function pointer */ |
22 |
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symbol, |
23 |
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list |
24 |
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} type; /* Type of stack element */ |
25 |
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|
26 |
union { |
union { |
27 |
void* ptr; |
void* ptr; /* Pointer to the content */ |
28 |
int val; |
int val; /* ...or an integer */ |
29 |
} content; |
} content; /* Stores a pointer or an integer */ |
30 |
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|
31 |
char* id; |
char* id; /* Symbol name */ |
32 |
struct stack_item* next; |
struct stack_item* next; /* Next element */ |
33 |
} stackitem; |
} stackitem; |
34 |
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|
35 |
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36 |
typedef stackitem* hashtbl[HASHTBLSIZE]; |
typedef stackitem* hashtbl[HASHTBLSIZE]; /* Hash table declaration */ |
37 |
typedef void (*funcp)(stackitem**); |
typedef void (*funcp)(stackitem**); /* funcp is a pointer to a |
38 |
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void function (stackitem **) */ |
39 |
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|
40 |
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/* Initialize a newly created hash table. */ |
41 |
void init_hashtbl(hashtbl out_hash) |
void init_hashtbl(hashtbl out_hash) |
42 |
{ |
{ |
43 |
long i; |
long i; |
46 |
out_hash[i]= NULL; |
out_hash[i]= NULL; |
47 |
} |
} |
48 |
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|
49 |
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/* Returns a pointer to an element in the hash table. */ |
50 |
stackitem** hash(hashtbl in_hashtbl, const char* in_string) |
stackitem** hash(hashtbl in_hashtbl, const char* in_string) |
51 |
{ |
{ |
52 |
long i= 0; |
long i= 0; |
53 |
unsigned long out_hash= 0; |
unsigned long out_hash= 0; |
54 |
char key= 0; |
char key= '\0'; |
55 |
stackitem** position; |
stackitem** position; |
56 |
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|
57 |
while(1){ |
while(1){ /* Hash in_string */ |
58 |
key= in_string[i++]; |
key= in_string[i++]; |
59 |
if(key=='\0') |
if(key=='\0') |
60 |
break; |
break; |
64 |
out_hash= out_hash%HASHTBLSIZE; |
out_hash= out_hash%HASHTBLSIZE; |
65 |
position= &(in_hashtbl[out_hash]); |
position= &(in_hashtbl[out_hash]); |
66 |
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|
67 |
while(1){ |
while(position != NULL){ |
68 |
if(*position==NULL) |
if(*position==NULL) /* If empty */ |
69 |
return position; |
return position; |
70 |
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|
71 |
if(strcmp(in_string, (*position)->id)==0) |
if(strcmp(in_string, (*position)->id)==0) /* If match */ |
72 |
return position; |
return position; |
73 |
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|
74 |
position= &((*position)->next); |
position= &((*position)->next); /* Try next */ |
75 |
} |
} |
76 |
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return NULL; /* end of list reached without finding |
77 |
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an empty position */ |
78 |
} |
} |
79 |
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|
80 |
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/* Generic push function. */ |
81 |
int push(stackitem** stack_head, stackitem* in_item) |
int push(stackitem** stack_head, stackitem* in_item) |
82 |
{ |
{ |
83 |
in_item->next= *stack_head; |
in_item->next= *stack_head; |
85 |
return 1; |
return 1; |
86 |
} |
} |
87 |
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|
88 |
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/* Push a value on the stack. */ |
89 |
int push_val(stackitem** stack_head, int in_val) |
int push_val(stackitem** stack_head, int in_val) |
90 |
{ |
{ |
91 |
stackitem* new_item= malloc(sizeof(stackitem)); |
stackitem* new_item= malloc(sizeof(stackitem)); |
92 |
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assert(new_item != NULL); |
93 |
new_item->content.val= in_val; |
new_item->content.val= in_val; |
94 |
new_item->type= value; |
new_item->type= value; |
95 |
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|
97 |
return 1; |
return 1; |
98 |
} |
} |
99 |
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|
100 |
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/* Copy a string onto the stack. */ |
101 |
int push_cstring(stackitem** stack_head, const char* in_string) |
int push_cstring(stackitem** stack_head, const char* in_string) |
102 |
{ |
{ |
103 |
stackitem* new_item= malloc(sizeof(stackitem)); |
stackitem* new_item= malloc(sizeof(stackitem)); |
109 |
return 1; |
return 1; |
110 |
} |
} |
111 |
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|
112 |
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/* Create a new hash entry. */ |
113 |
int mk_hashentry(hashtbl in_hashtbl, stackitem* in_item, const char* id) |
int mk_hashentry(hashtbl in_hashtbl, stackitem* in_item, const char* id) |
114 |
{ |
{ |
115 |
in_item->id= malloc(strlen(id)+1); |
in_item->id= malloc(strlen(id)+1); |
120 |
return 1; |
return 1; |
121 |
} |
} |
122 |
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|
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/* Define a new function in the hash table. */ |
124 |
void def_func(hashtbl in_hashtbl, funcp in_func, const char* id) |
void def_func(hashtbl in_hashtbl, funcp in_func, const char* id) |
125 |
{ |
{ |
126 |
stackitem* temp= malloc(sizeof(stackitem)); |
stackitem* temp= malloc(sizeof(stackitem)); |
131 |
mk_hashentry(in_hashtbl, temp, id); |
mk_hashentry(in_hashtbl, temp, id); |
132 |
} |
} |
133 |
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|
134 |
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/* Define a new symbol in the hash table. */ |
135 |
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void def_sym(hashtbl in_hashtbl, const char* id) |
136 |
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{ |
137 |
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stackitem* temp= malloc(sizeof(stackitem)); |
138 |
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|
139 |
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temp->type= symbol; |
140 |
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mk_hashentry(in_hashtbl, temp, id); |
141 |
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} |
142 |
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|
143 |
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/* Push a reference to an entry in the hash table onto the stack. */ |
144 |
int push_ref(stackitem** stack_head, hashtbl in_hash, const char* in_string) |
int push_ref(stackitem** stack_head, hashtbl in_hash, const char* in_string) |
145 |
{ |
{ |
146 |
void* handle; |
static void* handle= NULL; |
147 |
void* symbol; |
void* symbol; |
148 |
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|
149 |
stackitem* new_item= malloc(sizeof(stackitem)); |
stackitem* new_item= malloc(sizeof(stackitem)); |
150 |
new_item->content.ptr= *hash(in_hash, in_string); |
new_item->content.ptr= *hash(in_hash, in_string); |
151 |
new_item->type= ref; |
new_item->type= ref; |
152 |
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|
153 |
if(new_item->content.ptr==NULL) { |
if(new_item->content.ptr==NULL) { /* If hash entry empty */ |
154 |
handle= dlopen(NULL, RTLD_LAZY); |
if(handle==NULL) /* If no handle */ |
155 |
symbol= dlsym(handle, in_string); |
handle= dlopen(NULL, RTLD_LAZY); |
156 |
if(dlerror()==NULL) { |
|
157 |
def_func(in_hash, symbol, in_string); |
symbol= dlsym(handle, in_string); /* Get function pointer */ |
158 |
new_item->content.ptr= *hash(in_hash, in_string); |
if(dlerror()==NULL) /* If existing function pointer */ |
159 |
new_item->type= ref; |
def_func(in_hash, symbol, in_string); /* Store function pointer */ |
160 |
} |
else |
161 |
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def_sym(in_hash, in_string); /* Make symbol */ |
162 |
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|
163 |
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new_item->content.ptr= *hash(in_hash, in_string); /* XXX */ |
164 |
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new_item->type= ref; |
165 |
} |
} |
166 |
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|
167 |
push(stack_head, new_item); |
push(stack_head, new_item); |
168 |
return 1; |
return 1; |
169 |
} |
} |
170 |
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|
171 |
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void printerr(const char* in_string) { |
172 |
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fprintf(stderr, "Err: %s\n", in_string); |
173 |
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} |
174 |
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|
175 |
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/* Discard the top element of the stack. */ |
176 |
extern void toss(stackitem** stack_head) |
extern void toss(stackitem** stack_head) |
177 |
{ |
{ |
178 |
stackitem* temp= *stack_head; |
stackitem* temp= *stack_head; |
179 |
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|
180 |
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if((*stack_head)==NULL) { |
181 |
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printerr("Stack empty"); |
182 |
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return; |
183 |
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} |
184 |
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|
185 |
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if((*stack_head)->type==string) |
186 |
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free((*stack_head)->content.ptr); |
187 |
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|
188 |
*stack_head= (*stack_head)->next; |
*stack_head= (*stack_head)->next; |
189 |
free(temp); |
free(temp); |
190 |
} |
} |
191 |
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|
192 |
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/* Print newline. */ |
193 |
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extern void nl() |
194 |
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{ |
195 |
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printf("\n"); |
196 |
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} |
197 |
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|
198 |
/* print_stack(stack); */ |
/* Prints the top element of the stack. */ |
199 |
void print_st(stackitem* stack_head, long counter) |
void print_(stackitem** stack_head) |
200 |
{ |
{ |
201 |
if(stack_head->next != NULL) |
if((*stack_head)==NULL) { |
202 |
print_st(stack_head->next, counter+1); |
printerr("Stack empty"); |
203 |
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return; |
204 |
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} |
205 |
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|
206 |
switch(stack_head->type){ |
switch((*stack_head)->type) { |
207 |
case value: |
case value: |
208 |
printf("%ld: %d\n", counter, (int)stack_head->content.val); |
printf("%d", (*stack_head)->content.val); |
209 |
break; |
break; |
210 |
case string: |
case string: |
211 |
printf("%ld: \"%s\"\n", counter, (char*)stack_head->content.ptr); |
printf("%s", (char*)(*stack_head)->content.ptr); |
212 |
break; |
break; |
213 |
case ref: |
case ref: |
214 |
case func: |
printf("%s", ((stackitem*)(*stack_head)->content.ptr)->id); |
215 |
printf("%ld: %p\n", counter, stack_head->content.ptr); |
break; |
216 |
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case symbol: |
217 |
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default: |
218 |
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printf("%p", (*stack_head)->content.ptr); |
219 |
break; |
break; |
220 |
} |
} |
221 |
} |
} |
222 |
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|
223 |
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/* Prints the top element of the stack and then discards it. */ |
224 |
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extern void print(stackitem** stack_head) |
225 |
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{ |
226 |
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print_(stack_head); |
227 |
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toss(stack_head); |
228 |
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} |
229 |
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230 |
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/* Only to be called by function printstack. */ |
231 |
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void print_st(stackitem* stack_head, long counter) |
232 |
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{ |
233 |
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if(stack_head->next != NULL) |
234 |
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print_st(stack_head->next, counter+1); |
235 |
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|
236 |
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printf("%ld: ", counter); |
237 |
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print_(&stack_head); |
238 |
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nl(); |
239 |
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} |
240 |
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|
241 |
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/* Prints the stack. */ |
242 |
extern void printstack(stackitem** stack_head) |
extern void printstack(stackitem** stack_head) |
243 |
{ |
{ |
244 |
if(*stack_head != NULL) { |
if(*stack_head != NULL) { |
245 |
print_st(*stack_head, 1); |
print_st(*stack_head, 1); |
246 |
printf("\n"); |
printf("\n"); |
247 |
|
} else { |
248 |
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printerr("Stack empty"); |
249 |
} |
} |
250 |
} |
} |
251 |
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|
252 |
|
/* If the top element is a reference, determine if it's a reference to a |
253 |
|
function, and if it is, toss the reference and execute the function. */ |
254 |
extern void eval(stackitem** stack_head) |
extern void eval(stackitem** stack_head) |
255 |
{ |
{ |
256 |
funcp in_func; |
funcp in_func; |
257 |
|
|
258 |
if((*stack_head)==NULL || (*stack_head)->type!=ref) |
if((*stack_head)==NULL || (*stack_head)->type!=ref) { |
259 |
|
printerr("Stack empty or not a reference"); |
260 |
return; |
return; |
261 |
|
} |
262 |
|
|
263 |
if(((stackitem*)(*stack_head)->content.ptr)->type==func) { |
if(((stackitem*)(*stack_head)->content.ptr)->type==func) { |
264 |
in_func= (funcp)((stackitem*)(*stack_head)->content.ptr)->content.ptr; |
in_func= (funcp)((stackitem*)(*stack_head)->content.ptr)->content.ptr; |
265 |
toss(stack_head); |
toss(stack_head); |
266 |
(*in_func)(stack_head); |
(*in_func)(stack_head); |
267 |
return; |
return; |
268 |
|
} else |
269 |
|
printerr("Not a function"); |
270 |
|
} |
271 |
|
|
272 |
|
/* Make a list. */ |
273 |
|
extern void pack(stackitem** stack_head) |
274 |
|
{ |
275 |
|
void* delimiter; |
276 |
|
stackitem *iterator, *temp, *pack; |
277 |
|
|
278 |
|
if((*stack_head)==NULL) { |
279 |
|
printerr("Stack empty"); |
280 |
|
return; |
281 |
} |
} |
282 |
|
|
283 |
|
delimiter= (*stack_head)->content.ptr; /* Get delimiter */ |
284 |
|
toss(stack_head); |
285 |
|
|
286 |
|
iterator= *stack_head; |
287 |
|
|
288 |
|
/* Search for first delimiter */ |
289 |
|
while(iterator->next!=NULL && iterator->next->content.ptr!=delimiter) |
290 |
|
iterator= iterator->next; |
291 |
|
|
292 |
|
/* Extract list */ |
293 |
|
temp= *stack_head; |
294 |
|
*stack_head= iterator->next; |
295 |
|
iterator->next= NULL; |
296 |
|
|
297 |
|
if(*stack_head!=NULL && (*stack_head)->content.ptr==delimiter) |
298 |
|
toss(stack_head); |
299 |
|
|
300 |
|
/* Push list */ |
301 |
|
pack= malloc(sizeof(stackitem)); |
302 |
|
pack->type= list; |
303 |
|
pack->content.ptr= temp; |
304 |
|
|
305 |
|
push(stack_head, pack); |
306 |
} |
} |
307 |
|
|
308 |
|
/* Parse input. */ |
309 |
int stack_read(stackitem** stack_head, hashtbl in_hash, char* in_line) |
int stack_read(stackitem** stack_head, hashtbl in_hash, char* in_line) |
310 |
{ |
{ |
311 |
char *temp, *rest; |
char *temp, *rest; |
316 |
temp= malloc(inlength); |
temp= malloc(inlength); |
317 |
rest= malloc(inlength); |
rest= malloc(inlength); |
318 |
|
|
319 |
if((convert= sscanf(in_line, "\"%[^\"\n\r]\" %[^\n\r]", temp, rest)) >= 1) |
do { |
320 |
push_cstring(stack_head, temp); |
/* If string */ |
321 |
else if((convert= sscanf(in_line, "%d %[^\n\r]", &itemp, rest)) >= 1) |
if((convert= sscanf(in_line, "\"%[^\"\n\r]\" %[^\n\r]", temp, rest))) { |
322 |
push_val(stack_head, itemp); |
push_cstring(stack_head, temp); |
323 |
else if((convert= sscanf(in_line, "%[^ ;\n\r]%[^\n\r]", temp, rest)) >= 1) |
break; |
324 |
push_ref(stack_head, in_hash, temp); |
} |
325 |
else if((convert= sscanf(in_line, "%c%[^\n\r]", temp, rest)) >= 1) |
/* If value */ |
326 |
if(*temp==';') |
if((convert= sscanf(in_line, "%d %[^\n\r]", &itemp, rest))) { |
327 |
eval(stack_head); |
push_val(stack_head, itemp); |
328 |
|
break; |
329 |
|
} |
330 |
|
/* Escape ';' with '\' */ |
331 |
|
if((convert= sscanf(in_line, "\\%c%[^\n\r]", temp, rest))) { |
332 |
|
temp[1]= '\0'; |
333 |
|
push_ref(stack_head, in_hash, temp); |
334 |
|
break; |
335 |
|
} |
336 |
|
/* If symbol */ |
337 |
|
if((convert= sscanf(in_line, "%[^] ;\n\r]%[^\n\r]", temp, rest))) { |
338 |
|
push_ref(stack_head, in_hash, temp); |
339 |
|
break; |
340 |
|
} |
341 |
|
/* If single char */ |
342 |
|
if((convert= sscanf(in_line, "%c%[^\n\r]", temp, rest))) { |
343 |
|
if(*temp==';') { |
344 |
|
eval(stack_head); /* Evaluate top element */ |
345 |
|
break; |
346 |
|
} |
347 |
|
|
348 |
|
if(*temp==']') { |
349 |
|
push_ref(stack_head, in_hash, "["); |
350 |
|
pack(stack_head); |
351 |
|
break; |
352 |
|
} |
353 |
|
} |
354 |
|
} while(0); |
355 |
|
|
356 |
|
|
357 |
free(temp); |
free(temp); |
358 |
|
|
367 |
return 1; |
return 1; |
368 |
} |
} |
369 |
|
|
370 |
extern void print(stackitem** stack_head) |
/* Relocate elements of the list on the stack. */ |
371 |
|
extern void expand(stackitem** stack_head) |
372 |
{ |
{ |
373 |
if((*stack_head)==NULL) |
stackitem *temp, *new_head; |
374 |
|
|
375 |
|
/* Is top element a list? */ |
376 |
|
if((*stack_head)==NULL || (*stack_head)->type!=list) { |
377 |
|
printerr("Stack empty or not a list"); |
378 |
return; |
return; |
379 |
|
} |
380 |
|
|
381 |
if((*stack_head)->type==value) |
/* The first list element is the new stack head */ |
382 |
printf("%d", (*stack_head)->content.val); |
new_head= temp= (*stack_head)->content.ptr; |
383 |
else if((*stack_head)->type==string) |
toss(stack_head); |
384 |
printf("%s", (char*)(*stack_head)->content.ptr); |
|
385 |
else |
/* Search the end of the list */ |
386 |
printf("%p", (*stack_head)->content.ptr); |
while(temp->next!=NULL) |
387 |
|
temp= temp->next; |
388 |
|
|
389 |
|
/* Connect the the tail of the list with the old stack head */ |
390 |
|
temp->next= *stack_head; |
391 |
|
*stack_head= new_head; /* ...and voila! */ |
392 |
|
} |
393 |
|
|
394 |
|
/* Swap the two top elements on the stack. */ |
395 |
|
extern void swap(stackitem** stack_head) |
396 |
|
{ |
397 |
|
stackitem* temp= (*stack_head); |
398 |
|
|
399 |
|
if((*stack_head)==NULL) { |
400 |
|
printerr("Stack empty"); |
401 |
|
return; |
402 |
|
} |
403 |
|
|
404 |
|
if((*stack_head)->next==NULL) |
405 |
|
return; |
406 |
|
|
407 |
|
*stack_head= (*stack_head)->next; |
408 |
|
temp->next= (*stack_head)->next; |
409 |
|
(*stack_head)->next= temp; |
410 |
|
} |
411 |
|
|
412 |
|
/* Compares two elements by reference. */ |
413 |
|
extern void eq(stackitem** stack_head) |
414 |
|
{ |
415 |
|
void *left, *right; |
416 |
|
int result; |
417 |
|
|
418 |
|
if((*stack_head)==NULL || (*stack_head)->next==NULL) { |
419 |
|
printerr("Not enough elements to compare"); |
420 |
|
return; |
421 |
|
} |
422 |
|
|
423 |
|
left= (*stack_head)->content.ptr; |
424 |
|
swap(stack_head); |
425 |
|
right= (*stack_head)->content.ptr; |
426 |
|
result= (left==right); |
427 |
|
|
428 |
|
toss(stack_head); toss(stack_head); |
429 |
|
push_val(stack_head, (left==right)); |
430 |
|
} |
431 |
|
|
432 |
|
/* Negates the top element on the stack. */ |
433 |
|
extern void not(stackitem** stack_head) |
434 |
|
{ |
435 |
|
int value; |
436 |
|
|
437 |
|
if((*stack_head)==NULL || (*stack_head)->type!=value) { |
438 |
|
printerr("Stack empty or element is not a value"); |
439 |
|
return; |
440 |
|
} |
441 |
|
|
442 |
|
value= (*stack_head)->content.val; |
443 |
toss(stack_head); |
toss(stack_head); |
444 |
|
push_val(stack_head, !value); |
445 |
} |
} |
446 |
|
|
447 |
extern void nl() |
/* Compares the two top elements on the stack and return 0 if they're the |
448 |
|
same. */ |
449 |
|
extern void neq(stackitem** stack_head) |
450 |
{ |
{ |
451 |
printf("\n"); |
eq(stack_head); |
452 |
|
not(stack_head); |
453 |
|
} |
454 |
|
|
455 |
|
/* Give a symbol some content. */ |
456 |
|
extern void def(stackitem** stack_head) |
457 |
|
{ |
458 |
|
stackitem *temp, *value; |
459 |
|
|
460 |
|
if(*stack_head==NULL || (*stack_head)->next==NULL |
461 |
|
|| (*stack_head)->type!=ref) { |
462 |
|
printerr("Define what?"); |
463 |
|
return; |
464 |
|
} |
465 |
|
|
466 |
|
temp= (*stack_head)->content.ptr; |
467 |
|
value= (*stack_head)->next; |
468 |
|
temp->content= value->content; |
469 |
|
value->content.ptr=NULL; |
470 |
|
temp->type= value->type; |
471 |
|
|
472 |
|
toss(stack_head); toss(stack_head); |
473 |
|
} |
474 |
|
|
475 |
|
/* Quit stack. */ |
476 |
|
extern void quit() |
477 |
|
{ |
478 |
|
exit(EXIT_SUCCESS); |
479 |
} |
} |
480 |
|
|
481 |
int main() |
int main() |
493 |
printf("okidok\n "); |
printf("okidok\n "); |
494 |
} |
} |
495 |
|
|
496 |
|
exit(EXIT_SUCCESS); |
|
return EXIT_SUCCESS; |
|
497 |
} |
} |
498 |
|
|
499 |
|
/* Local Variables: */ |
500 |
|
/* compile-command:"make CFLAGS=\"-Wall -g -rdynamic -ldl\" stack" */ |
501 |
|
/* End: */ |