1 |
/* printf, sscanf, fgets, fprintf */ |
2 |
#include <stdio.h> |
3 |
/* exit, EXIT_SUCCESS, malloc, free */ |
4 |
#include <stdlib.h> |
5 |
/* NULL */ |
6 |
#include <stddef.h> |
7 |
/* dlopen, dlsym, dlerror */ |
8 |
#include <dlfcn.h> |
9 |
/* strcmp, strcpy, strlen, strcat, strdup */ |
10 |
#include <string.h> |
11 |
|
12 |
#define HASHTBLSIZE 65536 |
13 |
|
14 |
/* First, define some types. */ |
15 |
|
16 |
/* A value of some type */ |
17 |
typedef struct { |
18 |
enum { |
19 |
integer, |
20 |
string, |
21 |
func, /* Function pointer */ |
22 |
symb, |
23 |
list |
24 |
} type; /* Type of stack element */ |
25 |
|
26 |
union { |
27 |
void *ptr; /* Pointer to the content */ |
28 |
int val; /* ...or an integer */ |
29 |
} content; /* Stores a pointer or an integer */ |
30 |
|
31 |
int refcount; /* Reference counter */ |
32 |
|
33 |
} value; |
34 |
|
35 |
/* A symbol with a name and possible value */ |
36 |
/* (These do not need reference counters, they are kept unique by |
37 |
hashing.) */ |
38 |
typedef struct symbol_struct { |
39 |
char *id; /* Symbol name */ |
40 |
value *val; /* The value (if any) bound to it */ |
41 |
struct symbol_struct *next; /* In case of hashing conflicts, a */ |
42 |
} symbol; /* symbol is a kind of stack item. */ |
43 |
|
44 |
/* A type for a hash table for symbols */ |
45 |
typedef symbol *hashtbl[HASHTBLSIZE]; /* Hash table declaration */ |
46 |
|
47 |
/* An item (value) on a stack */ |
48 |
typedef struct stackitem_struct |
49 |
{ |
50 |
value *item; /* The value on the stack */ |
51 |
/* (This is never NULL) */ |
52 |
struct stackitem_struct *next; /* Next item */ |
53 |
} stackitem; |
54 |
|
55 |
/* An environment; gives access to the stack and a hash table of |
56 |
defined symbols */ |
57 |
typedef struct { |
58 |
stackitem *head; /* Head of the stack */ |
59 |
hashtbl symbols; /* Hash table of all variable bindings */ |
60 |
int err; /* Error flag */ |
61 |
int non_eval_flag; |
62 |
char *in_string; /* Input pending to be read */ |
63 |
} environment; |
64 |
|
65 |
/* A type for pointers to external functions */ |
66 |
typedef void (*funcp)(environment *); /* funcp is a pointer to a void |
67 |
function (environment *) */ |
68 |
|
69 |
/* Initialize a newly created environment */ |
70 |
void init_env(environment *env) |
71 |
{ |
72 |
int i; |
73 |
|
74 |
env->in_string= NULL; |
75 |
env->err= 0; |
76 |
env->non_eval_flag= 0; |
77 |
for(i= 0; i<HASHTBLSIZE; i++) |
78 |
env->symbols[i]= NULL; |
79 |
} |
80 |
|
81 |
void printerr(const char* in_string) { |
82 |
fprintf(stderr, "Err: %s\n", in_string); |
83 |
} |
84 |
|
85 |
/* Throw away a value */ |
86 |
void free_val(value *val){ |
87 |
stackitem *item, *temp; |
88 |
|
89 |
val->refcount--; /* Decrease the reference count */ |
90 |
if(val->refcount == 0){ |
91 |
switch (val->type){ /* and free the contents if necessary */ |
92 |
case string: |
93 |
free(val->content.ptr); |
94 |
break; |
95 |
case list: /* lists needs to be freed recursively */ |
96 |
item=val->content.ptr; |
97 |
while(item != NULL) { /* for all stack items */ |
98 |
free_val(item->item); /* free the value */ |
99 |
temp=item->next; /* save next ptr */ |
100 |
free(item); /* free the stackitem */ |
101 |
item=temp; /* go to next stackitem */ |
102 |
} |
103 |
free(val); /* Free the actual list value */ |
104 |
break; |
105 |
case integer: |
106 |
case func: |
107 |
case symb: |
108 |
break; |
109 |
} |
110 |
} |
111 |
} |
112 |
|
113 |
/* Discard the top element of the stack. */ |
114 |
extern void toss(environment *env) |
115 |
{ |
116 |
stackitem *temp= env->head; |
117 |
|
118 |
if((env->head)==NULL) { |
119 |
printerr("Too Few Arguments"); |
120 |
env->err=1; |
121 |
return; |
122 |
} |
123 |
|
124 |
free_val(env->head->item); /* Free the value */ |
125 |
env->head= env->head->next; /* Remove the top stack item */ |
126 |
free(temp); /* Free the old top stack item */ |
127 |
} |
128 |
|
129 |
/* Returns a pointer to a pointer to an element in the hash table. */ |
130 |
symbol **hash(hashtbl in_hashtbl, const char *in_string) |
131 |
{ |
132 |
int i= 0; |
133 |
unsigned int out_hash= 0; |
134 |
char key= '\0'; |
135 |
symbol **position; |
136 |
|
137 |
while(1){ /* Hash in_string */ |
138 |
key= in_string[i++]; |
139 |
if(key=='\0') |
140 |
break; |
141 |
out_hash= out_hash*32+key; |
142 |
} |
143 |
|
144 |
out_hash= out_hash%HASHTBLSIZE; |
145 |
position= &(in_hashtbl[out_hash]); |
146 |
|
147 |
while(1){ |
148 |
if(*position==NULL) /* If empty */ |
149 |
return position; |
150 |
|
151 |
if(strcmp(in_string, (*position)->id)==0) /* If match */ |
152 |
return position; |
153 |
|
154 |
position= &((*position)->next); /* Try next */ |
155 |
} |
156 |
} |
157 |
|
158 |
/* Generic push function. */ |
159 |
void push(stackitem** stack_head, stackitem* in_item) |
160 |
{ |
161 |
in_item->next= *stack_head; |
162 |
*stack_head= in_item; |
163 |
} |
164 |
|
165 |
/* Push a value onto the stack */ |
166 |
void push_val(stackitem **stack_head, value *val) |
167 |
{ |
168 |
stackitem *new_item= malloc(sizeof(stackitem)); |
169 |
new_item->item= val; |
170 |
val->refcount++; |
171 |
push(stack_head, new_item); |
172 |
} |
173 |
|
174 |
/* Push an integer onto the stack. */ |
175 |
void push_int(stackitem **stack_head, int in_val) |
176 |
{ |
177 |
value *new_value= malloc(sizeof(value)); |
178 |
stackitem *new_item= malloc(sizeof(stackitem)); |
179 |
new_item->item= new_value; |
180 |
|
181 |
new_value->content.val= in_val; |
182 |
new_value->type= integer; |
183 |
new_value->refcount=1; |
184 |
|
185 |
push(stack_head, new_item); |
186 |
} |
187 |
|
188 |
/* Copy a string onto the stack. */ |
189 |
void push_cstring(stackitem **stack_head, const char *in_string) |
190 |
{ |
191 |
value *new_value= malloc(sizeof(value)); |
192 |
stackitem *new_item= malloc(sizeof(stackitem)); |
193 |
new_item->item=new_value; |
194 |
|
195 |
new_value->content.ptr= malloc(strlen(in_string)+1); |
196 |
strcpy(new_value->content.ptr, in_string); |
197 |
new_value->type= string; |
198 |
new_value->refcount=1; |
199 |
|
200 |
push(stack_head, new_item); |
201 |
} |
202 |
|
203 |
/* Mangle a symbol name to a valid C identifier name */ |
204 |
char *mangle_str(const char *old_string){ |
205 |
char validchars[] |
206 |
="0123456789abcdef"; |
207 |
char *new_string, *current; |
208 |
|
209 |
new_string=malloc((strlen(old_string)*2)+4); |
210 |
strcpy(new_string, "sx_"); /* Stack eXternal */ |
211 |
current=new_string+3; |
212 |
while(old_string[0] != '\0'){ |
213 |
current[0]=validchars[(unsigned char)(old_string[0])/16]; |
214 |
current[1]=validchars[(unsigned char)(old_string[0])%16]; |
215 |
current+=2; |
216 |
old_string++; |
217 |
} |
218 |
current[0]='\0'; |
219 |
|
220 |
return new_string; /* The caller must free() it */ |
221 |
} |
222 |
|
223 |
extern void mangle(environment *env){ |
224 |
value *new_value; |
225 |
char *new_string; |
226 |
|
227 |
if((env->head)==NULL) { |
228 |
printerr("Too Few Arguments"); |
229 |
env->err=1; |
230 |
return; |
231 |
} |
232 |
|
233 |
if(env->head->item->type!=string) { |
234 |
printerr("Bad Argument Type"); |
235 |
env->err=2; |
236 |
return; |
237 |
} |
238 |
|
239 |
new_string= mangle_str((const char *)(env->head->item->content.ptr)); |
240 |
|
241 |
toss(env); |
242 |
if(env->err) return; |
243 |
|
244 |
new_value= malloc(sizeof(value)); |
245 |
new_value->content.ptr= new_string; |
246 |
new_value->type= string; |
247 |
new_value->refcount=1; |
248 |
|
249 |
push_val(&(env->head), new_value); |
250 |
} |
251 |
|
252 |
/* Push a symbol onto the stack. */ |
253 |
void push_sym(environment *env, const char *in_string) |
254 |
{ |
255 |
stackitem *new_item; /* The new stack item */ |
256 |
/* ...which will contain... */ |
257 |
value *new_value; /* A new symbol value */ |
258 |
/* ...which might point to... */ |
259 |
symbol **new_symbol; /* (if needed) A new actual symbol */ |
260 |
/* ...which, if possible, will be bound to... */ |
261 |
value *new_fvalue; /* (if needed) A new function value */ |
262 |
/* ...which will point to... */ |
263 |
void *funcptr; /* A function pointer */ |
264 |
|
265 |
static void *handle= NULL; /* Dynamic linker handle */ |
266 |
const char *dlerr; /* Dynamic linker error */ |
267 |
char *mangled; /* Mangled function name */ |
268 |
|
269 |
/* Create a new stack item containing a new value */ |
270 |
new_item= malloc(sizeof(stackitem)); |
271 |
new_value= malloc(sizeof(value)); |
272 |
new_item->item=new_value; |
273 |
|
274 |
/* The new value is a symbol */ |
275 |
new_value->type= symb; |
276 |
new_value->refcount= 1; |
277 |
|
278 |
/* Look up the symbol name in the hash table */ |
279 |
new_symbol= hash(env->symbols, in_string); |
280 |
new_value->content.ptr= *new_symbol; |
281 |
|
282 |
if(*new_symbol==NULL) { /* If symbol was undefined */ |
283 |
|
284 |
/* Create a new symbol */ |
285 |
(*new_symbol)= malloc(sizeof(symbol)); |
286 |
(*new_symbol)->val= NULL; /* undefined value */ |
287 |
(*new_symbol)->next= NULL; |
288 |
(*new_symbol)->id= malloc(strlen(in_string)+1); |
289 |
strcpy((*new_symbol)->id, in_string); |
290 |
|
291 |
/* Intern the new symbol in the hash table */ |
292 |
new_value->content.ptr= *new_symbol; |
293 |
|
294 |
/* Try to load the symbol name as an external function, to see if |
295 |
we should bind the symbol to a new function pointer value */ |
296 |
if(handle==NULL) /* If no handle */ |
297 |
handle= dlopen(NULL, RTLD_LAZY); |
298 |
|
299 |
funcptr= dlsym(handle, in_string); /* Get function pointer */ |
300 |
dlerr=dlerror(); |
301 |
if(dlerr != NULL) { /* If no function was found */ |
302 |
mangled=mangle_str(in_string); |
303 |
funcptr= dlsym(handle, mangled); /* try mangling it */ |
304 |
free(mangled); |
305 |
dlerr=dlerror(); |
306 |
} |
307 |
if(dlerr==NULL) { /* If a function was found */ |
308 |
new_fvalue= malloc(sizeof(value)); /* Create a new value */ |
309 |
new_fvalue->type=func; /* The new value is a function pointer */ |
310 |
new_fvalue->content.ptr=funcptr; /* Store function pointer */ |
311 |
(*new_symbol)->val= new_fvalue; /* Bind the symbol to the new |
312 |
function value */ |
313 |
new_fvalue->refcount= 1; |
314 |
} |
315 |
} |
316 |
push(&(env->head), new_item); |
317 |
} |
318 |
|
319 |
/* Print newline. */ |
320 |
extern void nl() |
321 |
{ |
322 |
printf("\n"); |
323 |
} |
324 |
|
325 |
/* Gets the type of a value */ |
326 |
extern void type(environment *env){ |
327 |
int typenum; |
328 |
|
329 |
if((env->head)==NULL) { |
330 |
printerr("Too Few Arguments"); |
331 |
env->err=1; |
332 |
return; |
333 |
} |
334 |
typenum=env->head->item->type; |
335 |
toss(env); |
336 |
switch(typenum){ |
337 |
case integer: |
338 |
push_sym(env, "integer"); |
339 |
break; |
340 |
case string: |
341 |
push_sym(env, "string"); |
342 |
break; |
343 |
case symb: |
344 |
push_sym(env, "symbol"); |
345 |
break; |
346 |
case func: |
347 |
push_sym(env, "function"); |
348 |
break; |
349 |
case list: |
350 |
push_sym(env, "list"); |
351 |
break; |
352 |
} |
353 |
} |
354 |
|
355 |
/* Prints the top element of the stack. */ |
356 |
void print_h(stackitem *stack_head) |
357 |
{ |
358 |
switch(stack_head->item->type) { |
359 |
case integer: |
360 |
printf("%d", stack_head->item->content.val); |
361 |
break; |
362 |
case string: |
363 |
printf("%s", (char*)stack_head->item->content.ptr); |
364 |
break; |
365 |
case symb: |
366 |
printf("%s", ((symbol *)(stack_head->item->content.ptr))->id); |
367 |
break; |
368 |
case func: |
369 |
printf("#<function %p>", (funcp)(stack_head->item->content.ptr)); |
370 |
break; |
371 |
case list: |
372 |
/* A list is just a stack, so make stack_head point to it */ |
373 |
stack_head=(stackitem *)(stack_head->item->content.ptr); |
374 |
printf("[ "); |
375 |
while(stack_head != NULL) { |
376 |
print_h(stack_head); |
377 |
printf(" "); |
378 |
stack_head=stack_head->next; |
379 |
} |
380 |
printf("]"); |
381 |
break; |
382 |
} |
383 |
} |
384 |
|
385 |
extern void print_(environment *env) { |
386 |
if(env->head==NULL) { |
387 |
printerr("Too Few Arguments"); |
388 |
env->err=1; |
389 |
return; |
390 |
} |
391 |
print_h(env->head); |
392 |
} |
393 |
|
394 |
/* Prints the top element of the stack and then discards it. */ |
395 |
extern void print(environment *env) |
396 |
{ |
397 |
print_(env); |
398 |
if(env->err) return; |
399 |
toss(env); |
400 |
} |
401 |
|
402 |
/* Only to be called by function printstack. */ |
403 |
void print_st(stackitem *stack_head, long counter) |
404 |
{ |
405 |
if(stack_head->next != NULL) |
406 |
print_st(stack_head->next, counter+1); |
407 |
printf("%ld: ", counter); |
408 |
print_h(stack_head); |
409 |
nl(); |
410 |
} |
411 |
|
412 |
/* Prints the stack. */ |
413 |
extern void printstack(environment *env) |
414 |
{ |
415 |
if(env->head == NULL) { |
416 |
return; |
417 |
} |
418 |
print_st(env->head, 1); |
419 |
nl(); |
420 |
} |
421 |
|
422 |
/* Swap the two top elements on the stack. */ |
423 |
extern void swap(environment *env) |
424 |
{ |
425 |
stackitem *temp= env->head; |
426 |
|
427 |
if(env->head==NULL || env->head->next==NULL) { |
428 |
printerr("Too Few Arguments"); |
429 |
env->err=1; |
430 |
return; |
431 |
} |
432 |
|
433 |
env->head= env->head->next; |
434 |
temp->next= env->head->next; |
435 |
env->head->next= temp; |
436 |
} |
437 |
|
438 |
/* Rotate the first three elements on the stack. */ |
439 |
extern void rot(environment *env) |
440 |
{ |
441 |
stackitem *temp= env->head; |
442 |
|
443 |
if(env->head==NULL || env->head->next==NULL |
444 |
|| env->head->next->next==NULL) { |
445 |
printerr("Too Few Arguments"); |
446 |
env->err=1; |
447 |
return; |
448 |
} |
449 |
|
450 |
env->head= env->head->next->next; |
451 |
temp->next->next= env->head->next; |
452 |
env->head->next= temp; |
453 |
} |
454 |
|
455 |
/* Recall a value from a symbol, if bound */ |
456 |
extern void rcl(environment *env) |
457 |
{ |
458 |
value *val; |
459 |
|
460 |
if(env->head == NULL) { |
461 |
printerr("Too Few Arguments"); |
462 |
env->err=1; |
463 |
return; |
464 |
} |
465 |
|
466 |
if(env->head->item->type!=symb) { |
467 |
printerr("Bad Argument Type"); |
468 |
env->err=2; |
469 |
return; |
470 |
} |
471 |
|
472 |
val=((symbol *)(env->head->item->content.ptr))->val; |
473 |
if(val == NULL){ |
474 |
printerr("Unbound Variable"); |
475 |
env->err=3; |
476 |
return; |
477 |
} |
478 |
toss(env); /* toss the symbol */ |
479 |
if(env->err) return; |
480 |
push_val(&(env->head), val); /* Return its bound value */ |
481 |
} |
482 |
|
483 |
void stack_read(environment*, char*); |
484 |
|
485 |
/* If the top element is a symbol, determine if it's bound to a |
486 |
function value, and if it is, toss the symbol and execute the |
487 |
function. */ |
488 |
extern void eval(environment *env) |
489 |
{ |
490 |
funcp in_func; |
491 |
value* temp_val; |
492 |
stackitem* iterator; |
493 |
char* temp_string; |
494 |
|
495 |
if(env->head==NULL) { |
496 |
printerr("Too Few Arguments"); |
497 |
env->err=1; |
498 |
return; |
499 |
} |
500 |
|
501 |
eval_start: |
502 |
|
503 |
switch(env->head->item->type) { |
504 |
/* if it's a symbol */ |
505 |
case symb: |
506 |
rcl(env); /* get its contents */ |
507 |
if(env->err) return; |
508 |
if(env->head->item->type!=symb){ /* don't recurse symbols */ |
509 |
goto eval_start; |
510 |
} |
511 |
return; |
512 |
|
513 |
/* If it's a lone function value, run it */ |
514 |
case func: |
515 |
in_func= (funcp)(env->head->item->content.ptr); |
516 |
toss(env); |
517 |
if(env->err) return; |
518 |
return (*in_func)(env); |
519 |
|
520 |
/* If it's a list */ |
521 |
case list: |
522 |
temp_val= env->head->item; |
523 |
env->head->item->refcount++; |
524 |
toss(env); |
525 |
if(env->err) return; |
526 |
iterator= (stackitem*)temp_val->content.ptr; |
527 |
while(iterator!=NULL) { |
528 |
push_val(&(env->head), iterator->item); |
529 |
if(env->head->item->type==symb |
530 |
&& strcmp(";", ((symbol*)(env->head->item->content.ptr))->id)==0) { |
531 |
toss(env); |
532 |
if(env->err) return; |
533 |
if(iterator->next == NULL){ |
534 |
free_val(temp_val); |
535 |
goto eval_start; |
536 |
} |
537 |
eval(env); |
538 |
if(env->err) return; |
539 |
} |
540 |
iterator= iterator->next; |
541 |
} |
542 |
free_val(temp_val); |
543 |
return; |
544 |
|
545 |
/* If it's a string */ |
546 |
case string: |
547 |
temp_val= env->head->item; |
548 |
env->head->item->refcount++; |
549 |
toss(env); |
550 |
if(env->err) return; |
551 |
temp_string= malloc(strlen((char*)temp_val->content.ptr)+5); |
552 |
strcpy(temp_string, "[ "); |
553 |
strcpy(temp_string+2, (char*)temp_val->content.ptr); |
554 |
free_val(temp_val); |
555 |
strcat(temp_string, " ]"); |
556 |
stack_read(env, temp_string); |
557 |
free(temp_string); |
558 |
goto eval_start; |
559 |
|
560 |
case integer: |
561 |
return; |
562 |
} |
563 |
} |
564 |
|
565 |
/* Reverse (flip) a list */ |
566 |
extern void rev(environment *env){ |
567 |
stackitem *old_head, *new_head, *item; |
568 |
|
569 |
if((env->head)==NULL) { |
570 |
printerr("Too Few Arguments"); |
571 |
env->err=1; |
572 |
return; |
573 |
} |
574 |
|
575 |
if(env->head->item->type!=list) { |
576 |
printerr("Bad Argument Type"); |
577 |
env->err=2; |
578 |
return; |
579 |
} |
580 |
|
581 |
old_head=(stackitem *)(env->head->item->content.ptr); |
582 |
new_head=NULL; |
583 |
while(old_head != NULL){ |
584 |
item=old_head; |
585 |
old_head=old_head->next; |
586 |
item->next=new_head; |
587 |
new_head=item; |
588 |
} |
589 |
env->head->item->content.ptr=new_head; |
590 |
} |
591 |
|
592 |
/* Make a list. */ |
593 |
extern void pack(environment *env) |
594 |
{ |
595 |
void* delimiter; |
596 |
stackitem *iterator, *temp; |
597 |
value *pack; |
598 |
|
599 |
delimiter= env->head->item->content.ptr; /* Get delimiter */ |
600 |
toss(env); |
601 |
|
602 |
iterator= env->head; |
603 |
|
604 |
if(iterator==NULL || iterator->item->content.ptr==delimiter) { |
605 |
temp= NULL; |
606 |
toss(env); |
607 |
} else { |
608 |
/* Search for first delimiter */ |
609 |
while(iterator->next!=NULL |
610 |
&& iterator->next->item->content.ptr!=delimiter) |
611 |
iterator= iterator->next; |
612 |
|
613 |
/* Extract list */ |
614 |
temp= env->head; |
615 |
env->head= iterator->next; |
616 |
iterator->next= NULL; |
617 |
|
618 |
if(env->head!=NULL) |
619 |
toss(env); |
620 |
} |
621 |
|
622 |
/* Push list */ |
623 |
pack= malloc(sizeof(value)); |
624 |
pack->type= list; |
625 |
pack->content.ptr= temp; |
626 |
pack->refcount= 1; |
627 |
|
628 |
temp= malloc(sizeof(stackitem)); |
629 |
temp->item= pack; |
630 |
|
631 |
push(&(env->head), temp); |
632 |
rev(env); |
633 |
} |
634 |
|
635 |
/* Parse input. */ |
636 |
void stack_read(environment *env, char *in_line) |
637 |
{ |
638 |
char *temp, *rest; |
639 |
int itemp; |
640 |
size_t inlength= strlen(in_line)+1; |
641 |
int convert= 0; |
642 |
|
643 |
temp= malloc(inlength); |
644 |
rest= malloc(inlength); |
645 |
|
646 |
do { |
647 |
/* If comment */ |
648 |
if((convert= sscanf(in_line, "#%[^\n\r]", rest))) { |
649 |
free(temp); free(rest); |
650 |
return; |
651 |
} |
652 |
|
653 |
/* If string */ |
654 |
if((convert= sscanf(in_line, "\"%[^\"\n\r]\" %[^\n\r]", temp, rest))) { |
655 |
push_cstring(&(env->head), temp); |
656 |
break; |
657 |
} |
658 |
/* If integer */ |
659 |
if((convert= sscanf(in_line, "%d %[^\n\r]", &itemp, rest))) { |
660 |
push_int(&(env->head), itemp); |
661 |
break; |
662 |
} |
663 |
/* Escape ';' with '\' */ |
664 |
if((convert= sscanf(in_line, "\\%c%[^\n\r]", temp, rest))) { |
665 |
temp[1]= '\0'; |
666 |
push_sym(env, temp); |
667 |
break; |
668 |
} |
669 |
/* If symbol */ |
670 |
if((convert= sscanf(in_line, "%[^][ ;\n\r]%[^\n\r]", temp, rest))) { |
671 |
push_sym(env, temp); |
672 |
break; |
673 |
} |
674 |
/* If single char */ |
675 |
if((convert= sscanf(in_line, "%c%[^\n\r]", temp, rest))) { |
676 |
if(*temp==';') { |
677 |
if(!env->non_eval_flag) { |
678 |
eval(env); /* Evaluate top element */ |
679 |
break; |
680 |
} |
681 |
|
682 |
push_sym(env, ";"); |
683 |
break; |
684 |
} |
685 |
|
686 |
if(*temp==']') { |
687 |
push_sym(env, "["); |
688 |
pack(env); |
689 |
if(env->non_eval_flag) |
690 |
env->non_eval_flag--; |
691 |
break; |
692 |
} |
693 |
|
694 |
if(*temp=='[') { |
695 |
push_sym(env, "["); |
696 |
env->non_eval_flag++; |
697 |
break; |
698 |
} |
699 |
} |
700 |
} while(0); |
701 |
|
702 |
free(temp); |
703 |
|
704 |
if(convert<2) { |
705 |
free(rest); |
706 |
return; |
707 |
} |
708 |
|
709 |
stack_read(env, rest); |
710 |
|
711 |
free(rest); |
712 |
} |
713 |
|
714 |
/* Relocate elements of the list on the stack. */ |
715 |
extern void expand(environment *env) |
716 |
{ |
717 |
stackitem *temp, *new_head; |
718 |
|
719 |
/* Is top element a list? */ |
720 |
if(env->head==NULL) { |
721 |
printerr("Too Few Arguments"); |
722 |
env->err=1; |
723 |
return; |
724 |
} |
725 |
if(env->head->item->type!=list) { |
726 |
printerr("Bad Argument Type"); |
727 |
env->err=2; |
728 |
return; |
729 |
} |
730 |
|
731 |
rev(env); |
732 |
|
733 |
if(env->err) |
734 |
return; |
735 |
|
736 |
/* The first list element is the new stack head */ |
737 |
new_head= temp= env->head->item->content.ptr; |
738 |
|
739 |
env->head->item->refcount++; |
740 |
toss(env); |
741 |
|
742 |
/* Find the end of the list */ |
743 |
while(temp->next!=NULL) |
744 |
temp= temp->next; |
745 |
|
746 |
/* Connect the tail of the list with the old stack head */ |
747 |
temp->next= env->head; |
748 |
env->head= new_head; /* ...and voila! */ |
749 |
|
750 |
} |
751 |
|
752 |
/* Compares two elements by reference. */ |
753 |
extern void eq(environment *env) |
754 |
{ |
755 |
void *left, *right; |
756 |
int result; |
757 |
|
758 |
if((env->head)==NULL || env->head->next==NULL) { |
759 |
printerr("Too Few Arguments"); |
760 |
env->err=1; |
761 |
return; |
762 |
} |
763 |
|
764 |
left= env->head->item->content.ptr; |
765 |
swap(env); |
766 |
right= env->head->item->content.ptr; |
767 |
result= (left==right); |
768 |
|
769 |
toss(env); toss(env); |
770 |
push_int(&(env->head), result); |
771 |
} |
772 |
|
773 |
/* Negates the top element on the stack. */ |
774 |
extern void not(environment *env) |
775 |
{ |
776 |
int val; |
777 |
|
778 |
if((env->head)==NULL) { |
779 |
printerr("Too Few Arguments"); |
780 |
env->err=1; |
781 |
return; |
782 |
} |
783 |
|
784 |
if(env->head->item->type!=integer) { |
785 |
printerr("Bad Argument Type"); |
786 |
env->err=2; |
787 |
return; |
788 |
} |
789 |
|
790 |
val= env->head->item->content.val; |
791 |
toss(env); |
792 |
push_int(&(env->head), !val); |
793 |
} |
794 |
|
795 |
/* Compares the two top elements on the stack and return 0 if they're the |
796 |
same. */ |
797 |
extern void neq(environment *env) |
798 |
{ |
799 |
eq(env); |
800 |
not(env); |
801 |
} |
802 |
|
803 |
/* Give a symbol some content. */ |
804 |
extern void def(environment *env) |
805 |
{ |
806 |
symbol *sym; |
807 |
|
808 |
/* Needs two values on the stack, the top one must be a symbol */ |
809 |
if(env->head==NULL || env->head->next==NULL) { |
810 |
printerr("Too Few Arguments"); |
811 |
env->err=1; |
812 |
return; |
813 |
} |
814 |
|
815 |
if(env->head->item->type!=symb) { |
816 |
printerr("Bad Argument Type"); |
817 |
env->err=2; |
818 |
return; |
819 |
} |
820 |
|
821 |
/* long names are a pain */ |
822 |
sym=env->head->item->content.ptr; |
823 |
|
824 |
/* if the symbol was bound to something else, throw it away */ |
825 |
if(sym->val != NULL) |
826 |
free_val(sym->val); |
827 |
|
828 |
/* Bind the symbol to the value */ |
829 |
sym->val= env->head->next->item; |
830 |
sym->val->refcount++; /* Increase the reference counter */ |
831 |
|
832 |
toss(env); toss(env); |
833 |
} |
834 |
|
835 |
/* Quit stack. */ |
836 |
extern void quit(environment *env) |
837 |
{ |
838 |
exit(EXIT_SUCCESS); |
839 |
} |
840 |
|
841 |
/* Clear stack */ |
842 |
extern void clear(environment *env) |
843 |
{ |
844 |
while(env->head!=NULL) |
845 |
toss(env); |
846 |
} |
847 |
|
848 |
/* List all defined words */ |
849 |
extern void words(environment *env) |
850 |
{ |
851 |
symbol *temp; |
852 |
int i; |
853 |
|
854 |
for(i= 0; i<HASHTBLSIZE; i++) { |
855 |
temp= env->symbols[i]; |
856 |
while(temp!=NULL) { |
857 |
printf("%s\n", temp->id); |
858 |
temp= temp->next; |
859 |
} |
860 |
} |
861 |
} |
862 |
|
863 |
/* Forgets a symbol (remove it from the hash table) */ |
864 |
extern void forget(environment *env) |
865 |
{ |
866 |
char* sym_id; |
867 |
stackitem *stack_head= env->head; |
868 |
symbol **hash_entry, *temp; |
869 |
|
870 |
if(stack_head==NULL) { |
871 |
printerr("Too Few Arguments"); |
872 |
env->err=1; |
873 |
return; |
874 |
} |
875 |
|
876 |
if(stack_head->item->type!=symb) { |
877 |
printerr("Bad Argument Type"); |
878 |
env->err=2; |
879 |
return; |
880 |
} |
881 |
|
882 |
sym_id= ((symbol*)(stack_head->item->content.ptr))->id; |
883 |
toss(env); |
884 |
|
885 |
hash_entry= hash(env->symbols, sym_id); |
886 |
temp= *hash_entry; |
887 |
*hash_entry= (*hash_entry)->next; |
888 |
|
889 |
if(temp->val!=NULL) { |
890 |
free_val(temp->val); |
891 |
} |
892 |
free(temp->id); |
893 |
free(temp); |
894 |
} |
895 |
|
896 |
/* Returns the current error number to the stack */ |
897 |
extern void errn(environment *env){ |
898 |
push_int(&(env->head), env->err); |
899 |
} |
900 |
|
901 |
extern void read(environment*); |
902 |
|
903 |
int main() |
904 |
{ |
905 |
environment myenv; |
906 |
|
907 |
init_env(&myenv); |
908 |
|
909 |
while(1) { |
910 |
if(myenv.in_string==NULL) |
911 |
printf("okidok\n "); |
912 |
read(&myenv); |
913 |
if(myenv.err) { |
914 |
printf("(error %d) ", myenv.err); |
915 |
myenv.err=0; |
916 |
} else if(myenv.head->item->type==symb |
917 |
&& ((symbol*)(myenv.head->item->content.ptr))->id[0]==';') { |
918 |
toss(&myenv); /* No error check in main */ |
919 |
eval(&myenv); |
920 |
} |
921 |
} |
922 |
quit(&myenv); |
923 |
return EXIT_FAILURE; |
924 |
} |
925 |
|
926 |
/* + */ |
927 |
extern void sx_2b(environment *env) { |
928 |
int a, b; |
929 |
size_t len; |
930 |
char* new_string; |
931 |
value *a_val, *b_val; |
932 |
|
933 |
if((env->head)==NULL || env->head->next==NULL) { |
934 |
printerr("Too Few Arguments"); |
935 |
env->err=1; |
936 |
return; |
937 |
} |
938 |
|
939 |
if(env->head->item->type==string |
940 |
&& env->head->next->item->type==string) { |
941 |
a_val= env->head->item; |
942 |
b_val= env->head->next->item; |
943 |
a_val->refcount++; |
944 |
b_val->refcount++; |
945 |
toss(env); if(env->err) return; |
946 |
toss(env); if(env->err) return; |
947 |
len= strlen(a_val->content.ptr)+strlen(b_val->content.ptr)+1; |
948 |
new_string= malloc(len); |
949 |
strcpy(new_string, b_val->content.ptr); |
950 |
strcat(new_string, a_val->content.ptr); |
951 |
free_val(a_val); free_val(b_val); |
952 |
push_cstring(&(env->head), new_string); |
953 |
free(new_string); |
954 |
return; |
955 |
} |
956 |
|
957 |
if(env->head->item->type!=integer |
958 |
|| env->head->next->item->type!=integer) { |
959 |
printerr("Bad Argument Type"); |
960 |
env->err=2; |
961 |
return; |
962 |
} |
963 |
a=env->head->item->content.val; |
964 |
toss(env); |
965 |
if(env->err) return; |
966 |
if(env->head->item->refcount == 1) |
967 |
env->head->item->content.val += a; |
968 |
else { |
969 |
b=env->head->item->content.val; |
970 |
toss(env); |
971 |
if(env->err) return; |
972 |
push_int(&(env->head), a+b); |
973 |
} |
974 |
} |
975 |
|
976 |
/* - */ |
977 |
extern void sx_2d(environment *env) { |
978 |
int a, b; |
979 |
|
980 |
if((env->head)==NULL || env->head->next==NULL) { |
981 |
printerr("Too Few Arguments"); |
982 |
env->err=1; |
983 |
return; |
984 |
} |
985 |
|
986 |
if(env->head->item->type!=integer |
987 |
|| env->head->next->item->type!=integer) { |
988 |
printerr("Bad Argument Type"); |
989 |
env->err=2; |
990 |
return; |
991 |
} |
992 |
a=env->head->item->content.val; |
993 |
toss(env); |
994 |
if(env->err) return; |
995 |
if(env->head->item->refcount == 1) |
996 |
env->head->item->content.val -= a; |
997 |
else { |
998 |
b=env->head->item->content.val; |
999 |
toss(env); |
1000 |
if(env->err) return; |
1001 |
push_int(&(env->head), b-a); |
1002 |
} |
1003 |
} |
1004 |
|
1005 |
/* > */ |
1006 |
extern void sx_3e(environment *env) { |
1007 |
int a, b; |
1008 |
|
1009 |
if((env->head)==NULL || env->head->next==NULL) { |
1010 |
printerr("Too Few Arguments"); |
1011 |
env->err=1; |
1012 |
return; |
1013 |
} |
1014 |
|
1015 |
if(env->head->item->type!=integer |
1016 |
|| env->head->next->item->type!=integer) { |
1017 |
printerr("Bad Argument Type"); |
1018 |
env->err=2; |
1019 |
return; |
1020 |
} |
1021 |
a=env->head->item->content.val; |
1022 |
toss(env); |
1023 |
if(env->err) return; |
1024 |
if(env->head->item->refcount == 1) |
1025 |
env->head->item->content.val = (env->head->item->content.val > a); |
1026 |
else { |
1027 |
b=env->head->item->content.val; |
1028 |
toss(env); |
1029 |
if(env->err) return; |
1030 |
push_int(&(env->head), b>a); |
1031 |
} |
1032 |
} |
1033 |
|
1034 |
/* Return copy of a value */ |
1035 |
value *copy_val(value *old_value){ |
1036 |
stackitem *old_item, *new_item, *prev_item; |
1037 |
|
1038 |
value *new_value=malloc(sizeof(value)); |
1039 |
|
1040 |
new_value->type=old_value->type; |
1041 |
new_value->refcount=0; /* This is increased if/when this |
1042 |
value is referenced somewhere, like |
1043 |
in a stack item or a variable */ |
1044 |
switch(old_value->type){ |
1045 |
case integer: |
1046 |
new_value->content.val=old_value->content.val; |
1047 |
break; |
1048 |
case string: |
1049 |
(char *)(new_value->content.ptr) |
1050 |
= strdup((char *)(old_value->content.ptr)); |
1051 |
break; |
1052 |
case func: |
1053 |
case symb: |
1054 |
new_value->content.ptr=old_value->content.ptr; |
1055 |
break; |
1056 |
case list: |
1057 |
new_value->content.ptr=NULL; |
1058 |
|
1059 |
prev_item=NULL; |
1060 |
old_item=(stackitem *)(old_value->content.ptr); |
1061 |
|
1062 |
while(old_item != NULL) { /* While list is not empty */ |
1063 |
new_item= malloc(sizeof(stackitem)); |
1064 |
new_item->item=copy_val(old_item->item); /* recurse */ |
1065 |
new_item->next=NULL; |
1066 |
if(prev_item != NULL) /* If this wasn't the first item */ |
1067 |
prev_item->next=new_item; /* point the previous item to the |
1068 |
new item */ |
1069 |
else |
1070 |
new_value->content.ptr=new_item; |
1071 |
old_item=old_item->next; |
1072 |
prev_item=new_item; |
1073 |
} |
1074 |
break; |
1075 |
} |
1076 |
return new_value; |
1077 |
} |
1078 |
|
1079 |
/* duplicates an item on the stack */ |
1080 |
extern void dup(environment *env) { |
1081 |
if((env->head)==NULL) { |
1082 |
printerr("Too Few Arguments"); |
1083 |
env->err=1; |
1084 |
return; |
1085 |
} |
1086 |
push_val(&(env->head), copy_val(env->head->item)); |
1087 |
} |
1088 |
|
1089 |
/* "if", If-Then */ |
1090 |
extern void sx_6966(environment *env) { |
1091 |
|
1092 |
int truth; |
1093 |
|
1094 |
if((env->head)==NULL || env->head->next==NULL) { |
1095 |
printerr("Too Few Arguments"); |
1096 |
env->err=1; |
1097 |
return; |
1098 |
} |
1099 |
|
1100 |
if(env->head->next->item->type != integer) { |
1101 |
printerr("Bad Argument Type"); |
1102 |
env->err=2; |
1103 |
return; |
1104 |
} |
1105 |
|
1106 |
swap(env); |
1107 |
if(env->err) return; |
1108 |
|
1109 |
truth=env->head->item->content.val; |
1110 |
|
1111 |
toss(env); |
1112 |
if(env->err) return; |
1113 |
|
1114 |
if(truth) |
1115 |
eval(env); |
1116 |
else |
1117 |
toss(env); |
1118 |
} |
1119 |
|
1120 |
/* If-Then-Else */ |
1121 |
extern void ifelse(environment *env) { |
1122 |
|
1123 |
int truth; |
1124 |
|
1125 |
if((env->head)==NULL || env->head->next==NULL |
1126 |
|| env->head->next->next==NULL) { |
1127 |
printerr("Too Few Arguments"); |
1128 |
env->err=1; |
1129 |
return; |
1130 |
} |
1131 |
|
1132 |
if(env->head->next->next->item->type != integer) { |
1133 |
printerr("Bad Argument Type"); |
1134 |
env->err=2; |
1135 |
return; |
1136 |
} |
1137 |
|
1138 |
rot(env); |
1139 |
if(env->err) return; |
1140 |
|
1141 |
truth=env->head->item->content.val; |
1142 |
|
1143 |
toss(env); |
1144 |
if(env->err) return; |
1145 |
|
1146 |
if(!truth) |
1147 |
swap(env); |
1148 |
if(env->err) return; |
1149 |
|
1150 |
toss(env); |
1151 |
if(env->err) return; |
1152 |
|
1153 |
eval(env); |
1154 |
} |
1155 |
|
1156 |
/* while */ |
1157 |
extern void sx_7768696c65(environment *env) { |
1158 |
|
1159 |
int truth; |
1160 |
value *loop, *test; |
1161 |
|
1162 |
if((env->head)==NULL || env->head->next==NULL) { |
1163 |
printerr("Too Few Arguments"); |
1164 |
env->err=1; |
1165 |
return; |
1166 |
} |
1167 |
|
1168 |
loop= env->head->item; |
1169 |
loop->refcount++; |
1170 |
toss(env); if(env->err) return; |
1171 |
|
1172 |
test= env->head->item; |
1173 |
test->refcount++; |
1174 |
toss(env); if(env->err) return; |
1175 |
|
1176 |
do { |
1177 |
push_val(&(env->head), test); |
1178 |
eval(env); |
1179 |
|
1180 |
if(env->head->item->type != integer) { |
1181 |
printerr("Bad Argument Type"); |
1182 |
env->err=2; |
1183 |
return; |
1184 |
} |
1185 |
|
1186 |
truth= env->head->item->content.val; |
1187 |
toss(env); if(env->err) return; |
1188 |
|
1189 |
if(truth) { |
1190 |
push_val(&(env->head), loop); |
1191 |
eval(env); |
1192 |
} else { |
1193 |
toss(env); |
1194 |
} |
1195 |
|
1196 |
} while(truth); |
1197 |
|
1198 |
free_val(test); |
1199 |
free_val(loop); |
1200 |
} |
1201 |
|
1202 |
/* For-loop */ |
1203 |
extern void sx_666f72(environment *env) { |
1204 |
|
1205 |
value *loop, *foo; |
1206 |
stackitem *iterator; |
1207 |
|
1208 |
if((env->head)==NULL || env->head->next==NULL) { |
1209 |
printerr("Too Few Arguments"); |
1210 |
env->err=1; |
1211 |
return; |
1212 |
} |
1213 |
|
1214 |
if(env->head->next->item->type != list) { |
1215 |
printerr("Bad Argument Type"); |
1216 |
env->err=2; |
1217 |
return; |
1218 |
} |
1219 |
|
1220 |
loop= env->head->item; |
1221 |
loop->refcount++; |
1222 |
toss(env); if(env->err) return; |
1223 |
|
1224 |
foo= env->head->item; |
1225 |
foo->refcount++; |
1226 |
toss(env); if(env->err) return; |
1227 |
|
1228 |
iterator= foo->content.ptr; |
1229 |
|
1230 |
while(iterator!=NULL) { |
1231 |
push_val(&(env->head), iterator->item); |
1232 |
push_val(&(env->head), loop); |
1233 |
eval(env); if(env->err) return; |
1234 |
iterator= iterator->next; |
1235 |
} |
1236 |
|
1237 |
free_val(loop); |
1238 |
free_val(foo); |
1239 |
} |
1240 |
|
1241 |
/* 'to' */ |
1242 |
extern void to(environment *env) { |
1243 |
int i, start, ending; |
1244 |
|
1245 |
if((env->head)==NULL || env->head->next==NULL) { |
1246 |
printerr("Too Few Arguments"); |
1247 |
env->err=1; |
1248 |
return; |
1249 |
} |
1250 |
|
1251 |
if(env->head->item->type!=integer |
1252 |
|| env->head->next->item->type!=integer) { |
1253 |
printerr("Bad Argument Type"); |
1254 |
env->err=2; |
1255 |
return; |
1256 |
} |
1257 |
|
1258 |
ending= env->head->item->content.val; |
1259 |
toss(env); if(env->err) return; |
1260 |
start= env->head->item->content.val; |
1261 |
toss(env); if(env->err) return; |
1262 |
|
1263 |
push_sym(env, "["); |
1264 |
|
1265 |
if(ending>=start) { |
1266 |
for(i= start; i<=ending; i++) |
1267 |
push_int(&(env->head), i); |
1268 |
} else { |
1269 |
for(i= start; i>=ending; i--) |
1270 |
push_int(&(env->head), i); |
1271 |
} |
1272 |
|
1273 |
push_sym(env, "["); |
1274 |
pack(env); if(env->err) return; |
1275 |
} |
1276 |
|
1277 |
/* Read a string */ |
1278 |
extern void readline(environment *env) { |
1279 |
char in_string[101]; |
1280 |
|
1281 |
fgets(in_string, 100, stdin); |
1282 |
push_cstring(&(env->head), in_string); |
1283 |
} |
1284 |
|
1285 |
/* Read a value and place on stack */ |
1286 |
extern void read(environment *env) { |
1287 |
const char symbform[]= "%[a-zA-Z0-9!$%*+./:<=>?@^_~-]%100c"; |
1288 |
const char strform[]= "\"%[^\"]\"%100c"; |
1289 |
const char intform[]= "%i%100c"; |
1290 |
const char blankform[]= "%*[ \t]%100c"; |
1291 |
const char ebrackform[]= "%*1[]]%100c"; |
1292 |
const char semicform[]= "%*1[;]%100c"; |
1293 |
const char bbrackform[]= "%*1[[]%100c"; |
1294 |
|
1295 |
int itemp, rerun= 0; |
1296 |
static int depth= 0; |
1297 |
char *rest, *match; |
1298 |
size_t inlength; |
1299 |
|
1300 |
if(env->in_string==NULL) { |
1301 |
readline(env); if(env->err) return; |
1302 |
|
1303 |
env->in_string= malloc(strlen(env->head->item->content.ptr)+1); |
1304 |
strcpy(env->in_string, env->head->item->content.ptr); |
1305 |
toss(env); if(env->err) return; |
1306 |
} |
1307 |
|
1308 |
inlength= strlen(env->in_string)+1; |
1309 |
match= malloc(inlength); |
1310 |
rest= malloc(inlength); |
1311 |
|
1312 |
if(sscanf(env->in_string, blankform, rest)) { |
1313 |
rerun= 1; |
1314 |
} else if(sscanf(env->in_string, intform, &itemp, rest) > 0) { |
1315 |
push_int(&(env->head), itemp); |
1316 |
} else if(sscanf(env->in_string, strform, match, rest) > 0) { |
1317 |
push_cstring(&(env->head), match); |
1318 |
} else if(sscanf(env->in_string, symbform, match, rest) > 0) { |
1319 |
push_sym(env, match); |
1320 |
} else if(sscanf(env->in_string, ebrackform, rest) > 0) { |
1321 |
push_sym(env, "["); |
1322 |
pack(env); if(env->err) return; |
1323 |
if(depth!=0) depth--; |
1324 |
} else if(sscanf(env->in_string, semicform, rest) > 0) { |
1325 |
push_sym(env, ";"); |
1326 |
} else if(sscanf(env->in_string, bbrackform, rest) > 0) { |
1327 |
push_sym(env, "["); |
1328 |
depth++; |
1329 |
} else { |
1330 |
free(rest); |
1331 |
rest= NULL; |
1332 |
} |
1333 |
|
1334 |
free(env->in_string); |
1335 |
free(match); |
1336 |
|
1337 |
env->in_string= rest; |
1338 |
|
1339 |
if(rerun || depth) |
1340 |
return read(env); |
1341 |
} |