1 |
/* printf, sscanf, fgets, fprintf, fopen, perror */ |
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 |
/* getopt, STDIN_FILENO, STDOUT_FILENO */ |
12 |
#include <unistd.h> |
13 |
/* EX_NOINPUT, EX_USAGE */ |
14 |
#include <sysexits.h> |
15 |
/* mtrace, muntrace */ |
16 |
#include <mcheck.h> |
17 |
|
18 |
#define HASHTBLSIZE 2048 |
19 |
|
20 |
/* First, define some types. */ |
21 |
|
22 |
/* A value of some type */ |
23 |
typedef struct { |
24 |
enum { |
25 |
integer, |
26 |
string, |
27 |
func, /* Function pointer */ |
28 |
symb, |
29 |
list |
30 |
} type; /* Type of stack element */ |
31 |
|
32 |
union { |
33 |
void *ptr; /* Pointer to the content */ |
34 |
int val; /* ...or an integer */ |
35 |
} content; /* Stores a pointer or an integer */ |
36 |
|
37 |
int refcount; /* Reference counter */ |
38 |
|
39 |
} value; |
40 |
|
41 |
/* A symbol with a name and possible value */ |
42 |
/* (These do not need reference counters, they are kept unique by |
43 |
hashing.) */ |
44 |
typedef struct symbol_struct { |
45 |
char *id; /* Symbol name */ |
46 |
value *val; /* The value (if any) bound to it */ |
47 |
struct symbol_struct *next; /* In case of hashing conflicts, a */ |
48 |
} symbol; /* symbol is a kind of stack item. */ |
49 |
|
50 |
/* A type for a hash table for symbols */ |
51 |
typedef symbol *hashtbl[HASHTBLSIZE]; /* Hash table declaration */ |
52 |
|
53 |
/* An item (value) on a stack */ |
54 |
typedef struct stackitem_struct |
55 |
{ |
56 |
value *item; /* The value on the stack */ |
57 |
/* (This is never NULL) */ |
58 |
struct stackitem_struct *next; /* Next item */ |
59 |
} stackitem; |
60 |
|
61 |
/* An environment; gives access to the stack and a hash table of |
62 |
defined symbols */ |
63 |
typedef struct { |
64 |
stackitem *head; /* Head of the stack */ |
65 |
hashtbl symbols; /* Hash table of all variable bindings */ |
66 |
int err; /* Error flag */ |
67 |
char *in_string; /* Input pending to be read */ |
68 |
char *free_string; /* Free this string when all input is |
69 |
read from in_string */ |
70 |
FILE *inputstream; /* stdin or a file, most likely */ |
71 |
int interactive; /* print prompts, stack, etc */ |
72 |
} environment; |
73 |
|
74 |
/* A type for pointers to external functions */ |
75 |
typedef void (*funcp)(environment *); /* funcp is a pointer to a void |
76 |
function (environment *) */ |
77 |
|
78 |
/* Initialize a newly created environment */ |
79 |
void init_env(environment *env) |
80 |
{ |
81 |
int i; |
82 |
|
83 |
env->head= NULL; |
84 |
for(i= 0; i<HASHTBLSIZE; i++) |
85 |
env->symbols[i]= NULL; |
86 |
env->err= 0; |
87 |
env->in_string= NULL; |
88 |
env->free_string= NULL; |
89 |
env->inputstream= stdin; |
90 |
env->interactive= 1; |
91 |
} |
92 |
|
93 |
void printerr(const char* in_string) { |
94 |
fprintf(stderr, "Err: %s\n", in_string); |
95 |
} |
96 |
|
97 |
/* Throw away a value */ |
98 |
void free_val(value *val){ |
99 |
stackitem *item, *temp; |
100 |
|
101 |
val->refcount--; /* Decrease the reference count */ |
102 |
if(val->refcount == 0){ |
103 |
switch (val->type){ /* and free the contents if necessary */ |
104 |
case string: |
105 |
free(val->content.ptr); |
106 |
break; |
107 |
case list: /* lists needs to be freed recursively */ |
108 |
item=val->content.ptr; |
109 |
while(item != NULL) { /* for all stack items */ |
110 |
free_val(item->item); /* free the value */ |
111 |
temp=item->next; /* save next ptr */ |
112 |
free(item); /* free the stackitem */ |
113 |
item=temp; /* go to next stackitem */ |
114 |
} |
115 |
break; |
116 |
case integer: |
117 |
case func: |
118 |
break; |
119 |
case symb: |
120 |
free(((symbol*)(val->content.ptr))->id); |
121 |
if(((symbol*)(val->content.ptr))->val!=NULL) |
122 |
free_val(((symbol*)(val->content.ptr))->val); |
123 |
free(val->content.ptr); |
124 |
break; |
125 |
} |
126 |
free(val); /* Free the actual value structure */ |
127 |
} |
128 |
} |
129 |
|
130 |
/* Discard the top element of the stack. */ |
131 |
extern void toss(environment *env) |
132 |
{ |
133 |
stackitem *temp= env->head; |
134 |
|
135 |
if((env->head)==NULL) { |
136 |
printerr("Too Few Arguments"); |
137 |
env->err=1; |
138 |
return; |
139 |
} |
140 |
|
141 |
free_val(env->head->item); /* Free the value */ |
142 |
env->head= env->head->next; /* Remove the top stack item */ |
143 |
free(temp); /* Free the old top stack item */ |
144 |
} |
145 |
|
146 |
/* Returns a pointer to a pointer to an element in the hash table. */ |
147 |
symbol **hash(hashtbl in_hashtbl, const char *in_string) |
148 |
{ |
149 |
int i= 0; |
150 |
unsigned int out_hash= 0; |
151 |
char key= '\0'; |
152 |
symbol **position; |
153 |
|
154 |
while(1){ /* Hash in_string */ |
155 |
key= in_string[i++]; |
156 |
if(key=='\0') |
157 |
break; |
158 |
out_hash= out_hash*32+key; |
159 |
} |
160 |
|
161 |
out_hash= out_hash%HASHTBLSIZE; |
162 |
position= &(in_hashtbl[out_hash]); |
163 |
|
164 |
while(1){ |
165 |
if(*position==NULL) /* If empty */ |
166 |
return position; |
167 |
|
168 |
if(strcmp(in_string, (*position)->id)==0) /* If match */ |
169 |
return position; |
170 |
|
171 |
position= &((*position)->next); /* Try next */ |
172 |
} |
173 |
} |
174 |
|
175 |
/* Push a value onto the stack */ |
176 |
void push_val(environment *env, value *val) |
177 |
{ |
178 |
stackitem *new_item= malloc(sizeof(stackitem)); |
179 |
new_item->item= val; |
180 |
val->refcount++; |
181 |
new_item->next= env->head; |
182 |
env->head= new_item; |
183 |
} |
184 |
|
185 |
/* Push an integer onto the stack. */ |
186 |
void push_int(environment *env, int in_val) |
187 |
{ |
188 |
value *new_value= malloc(sizeof(value)); |
189 |
|
190 |
new_value->content.val= in_val; |
191 |
new_value->type= integer; |
192 |
new_value->refcount= 0; |
193 |
|
194 |
push_val(env, new_value); |
195 |
} |
196 |
|
197 |
/* Copy a string onto the stack. */ |
198 |
void push_cstring(environment *env, const char *in_string) |
199 |
{ |
200 |
value *new_value= malloc(sizeof(value)); |
201 |
|
202 |
new_value->content.ptr= malloc(strlen(in_string)+1); |
203 |
strcpy(new_value->content.ptr, in_string); |
204 |
new_value->type= string; |
205 |
new_value->refcount= 0; |
206 |
|
207 |
push_val(env, new_value); |
208 |
} |
209 |
|
210 |
/* Mangle a symbol name to a valid C identifier name */ |
211 |
char *mangle_str(const char *old_string){ |
212 |
char validchars[] |
213 |
="0123456789abcdef"; |
214 |
char *new_string, *current; |
215 |
|
216 |
new_string=malloc((strlen(old_string)*2)+4); |
217 |
strcpy(new_string, "sx_"); /* Stack eXternal */ |
218 |
current=new_string+3; |
219 |
while(old_string[0] != '\0'){ |
220 |
current[0]=validchars[(unsigned char)(old_string[0])/16]; |
221 |
current[1]=validchars[(unsigned char)(old_string[0])%16]; |
222 |
current+=2; |
223 |
old_string++; |
224 |
} |
225 |
current[0]='\0'; |
226 |
|
227 |
return new_string; /* The caller must free() it */ |
228 |
} |
229 |
|
230 |
extern void mangle(environment *env){ |
231 |
char *new_string; |
232 |
|
233 |
if((env->head)==NULL) { |
234 |
printerr("Too Few Arguments"); |
235 |
env->err=1; |
236 |
return; |
237 |
} |
238 |
|
239 |
if(env->head->item->type!=string) { |
240 |
printerr("Bad Argument Type"); |
241 |
env->err=2; |
242 |
return; |
243 |
} |
244 |
|
245 |
new_string= mangle_str((const char *)(env->head->item->content.ptr)); |
246 |
|
247 |
toss(env); |
248 |
if(env->err) return; |
249 |
|
250 |
push_cstring(env, new_string); |
251 |
} |
252 |
|
253 |
/* Push a symbol onto the stack. */ |
254 |
void push_sym(environment *env, const char *in_string) |
255 |
{ |
256 |
value *new_value; /* A new symbol value */ |
257 |
/* ...which might point to... */ |
258 |
symbol **new_symbol; /* (if needed) A new actual symbol */ |
259 |
/* ...which, if possible, will be bound to... */ |
260 |
value *new_fvalue; /* (if needed) A new function value */ |
261 |
/* ...which will point to... */ |
262 |
void *funcptr; /* A function pointer */ |
263 |
|
264 |
static void *handle= NULL; /* Dynamic linker handle */ |
265 |
const char *dlerr; /* Dynamic linker error */ |
266 |
char *mangled; /* Mangled function name */ |
267 |
|
268 |
new_value= malloc(sizeof(value)); |
269 |
|
270 |
/* The new value is a symbol */ |
271 |
new_value->type= symb; |
272 |
new_value->refcount= 1; |
273 |
|
274 |
/* Look up the symbol name in the hash table */ |
275 |
new_symbol= hash(env->symbols, in_string); |
276 |
new_value->content.ptr= *new_symbol; |
277 |
|
278 |
if(*new_symbol==NULL) { /* If symbol was undefined */ |
279 |
|
280 |
/* Create a new symbol */ |
281 |
(*new_symbol)= malloc(sizeof(symbol)); |
282 |
(*new_symbol)->val= NULL; /* undefined value */ |
283 |
(*new_symbol)->next= NULL; |
284 |
(*new_symbol)->id= malloc(strlen(in_string)+1); |
285 |
strcpy((*new_symbol)->id, in_string); |
286 |
|
287 |
/* Intern the new symbol in the hash table */ |
288 |
new_value->content.ptr= *new_symbol; |
289 |
|
290 |
/* Try to load the symbol name as an external function, to see if |
291 |
we should bind the symbol to a new function pointer value */ |
292 |
if(handle==NULL) /* If no handle */ |
293 |
handle= dlopen(NULL, RTLD_LAZY); |
294 |
|
295 |
funcptr= dlsym(handle, in_string); /* Get function pointer */ |
296 |
dlerr=dlerror(); |
297 |
if(dlerr != NULL) { /* If no function was found */ |
298 |
mangled=mangle_str(in_string); |
299 |
funcptr= dlsym(handle, mangled); /* try mangling it */ |
300 |
free(mangled); |
301 |
dlerr=dlerror(); |
302 |
} |
303 |
if(dlerr==NULL) { /* If a function was found */ |
304 |
new_fvalue= malloc(sizeof(value)); /* Create a new value */ |
305 |
new_fvalue->type=func; /* The new value is a function pointer */ |
306 |
new_fvalue->content.ptr=funcptr; /* Store function pointer */ |
307 |
(*new_symbol)->val= new_fvalue; /* Bind the symbol to the new |
308 |
function value */ |
309 |
new_fvalue->refcount= 1; |
310 |
} |
311 |
} |
312 |
push_val(env, new_value); |
313 |
} |
314 |
|
315 |
/* Print newline. */ |
316 |
extern void nl() |
317 |
{ |
318 |
printf("\n"); |
319 |
} |
320 |
|
321 |
/* Gets the type of a value */ |
322 |
extern void type(environment *env){ |
323 |
int typenum; |
324 |
|
325 |
if((env->head)==NULL) { |
326 |
printerr("Too Few Arguments"); |
327 |
env->err=1; |
328 |
return; |
329 |
} |
330 |
typenum=env->head->item->type; |
331 |
toss(env); |
332 |
switch(typenum){ |
333 |
case integer: |
334 |
push_sym(env, "integer"); |
335 |
break; |
336 |
case string: |
337 |
push_sym(env, "string"); |
338 |
break; |
339 |
case symb: |
340 |
push_sym(env, "symbol"); |
341 |
break; |
342 |
case func: |
343 |
push_sym(env, "function"); |
344 |
break; |
345 |
case list: |
346 |
push_sym(env, "list"); |
347 |
break; |
348 |
} |
349 |
} |
350 |
|
351 |
/* Prints the top element of the stack. */ |
352 |
void print_h(stackitem *stack_head, int noquote) |
353 |
{ |
354 |
switch(stack_head->item->type) { |
355 |
case integer: |
356 |
printf("%d", stack_head->item->content.val); |
357 |
break; |
358 |
case string: |
359 |
if(noquote) |
360 |
printf("%s", (char*)stack_head->item->content.ptr); |
361 |
else |
362 |
printf("\"%s\"", (char*)stack_head->item->content.ptr); |
363 |
break; |
364 |
case symb: |
365 |
printf("%s", ((symbol *)(stack_head->item->content.ptr))->id); |
366 |
break; |
367 |
case func: |
368 |
printf("#<function %p>", (funcp)(stack_head->item->content.ptr)); |
369 |
break; |
370 |
case list: |
371 |
/* A list is just a stack, so make stack_head point to it */ |
372 |
stack_head=(stackitem *)(stack_head->item->content.ptr); |
373 |
printf("[ "); |
374 |
while(stack_head != NULL) { |
375 |
print_h(stack_head, noquote); |
376 |
printf(" "); |
377 |
stack_head=stack_head->next; |
378 |
} |
379 |
printf("]"); |
380 |
break; |
381 |
} |
382 |
} |
383 |
|
384 |
extern void print_(environment *env) { |
385 |
if(env->head==NULL) { |
386 |
printerr("Too Few Arguments"); |
387 |
env->err=1; |
388 |
return; |
389 |
} |
390 |
print_h(env->head, 0); |
391 |
nl(); |
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 |
extern void princ_(environment *env) { |
403 |
if(env->head==NULL) { |
404 |
printerr("Too Few Arguments"); |
405 |
env->err=1; |
406 |
return; |
407 |
} |
408 |
print_h(env->head, 1); |
409 |
} |
410 |
|
411 |
/* Prints the top element of the stack and then discards it. */ |
412 |
extern void princ(environment *env) |
413 |
{ |
414 |
princ_(env); |
415 |
if(env->err) return; |
416 |
toss(env); |
417 |
} |
418 |
|
419 |
/* Only to be called by function printstack. */ |
420 |
void print_st(stackitem *stack_head, long counter) |
421 |
{ |
422 |
if(stack_head->next != NULL) |
423 |
print_st(stack_head->next, counter+1); |
424 |
printf("%ld: ", counter); |
425 |
print_h(stack_head, 0); |
426 |
nl(); |
427 |
} |
428 |
|
429 |
/* Prints the stack. */ |
430 |
extern void printstack(environment *env) |
431 |
{ |
432 |
if(env->head == NULL) { |
433 |
printf("Stack Empty\n"); |
434 |
return; |
435 |
} |
436 |
print_st(env->head, 1); |
437 |
} |
438 |
|
439 |
/* Swap the two top elements on the stack. */ |
440 |
extern void swap(environment *env) |
441 |
{ |
442 |
stackitem *temp= env->head; |
443 |
|
444 |
if(env->head==NULL || env->head->next==NULL) { |
445 |
printerr("Too Few Arguments"); |
446 |
env->err=1; |
447 |
return; |
448 |
} |
449 |
|
450 |
env->head= env->head->next; |
451 |
temp->next= env->head->next; |
452 |
env->head->next= temp; |
453 |
} |
454 |
|
455 |
/* Rotate the first three elements on the stack. */ |
456 |
extern void rot(environment *env) |
457 |
{ |
458 |
stackitem *temp= env->head; |
459 |
|
460 |
if(env->head==NULL || env->head->next==NULL |
461 |
|| env->head->next->next==NULL) { |
462 |
printerr("Too Few Arguments"); |
463 |
env->err=1; |
464 |
return; |
465 |
} |
466 |
|
467 |
env->head= env->head->next->next; |
468 |
temp->next->next= env->head->next; |
469 |
env->head->next= temp; |
470 |
} |
471 |
|
472 |
/* Recall a value from a symbol, if bound */ |
473 |
extern void rcl(environment *env) |
474 |
{ |
475 |
value *val; |
476 |
|
477 |
if(env->head == NULL) { |
478 |
printerr("Too Few Arguments"); |
479 |
env->err=1; |
480 |
return; |
481 |
} |
482 |
|
483 |
if(env->head->item->type!=symb) { |
484 |
printerr("Bad Argument Type"); |
485 |
env->err=2; |
486 |
return; |
487 |
} |
488 |
|
489 |
val=((symbol *)(env->head->item->content.ptr))->val; |
490 |
if(val == NULL){ |
491 |
printerr("Unbound Variable"); |
492 |
env->err=3; |
493 |
return; |
494 |
} |
495 |
toss(env); /* toss the symbol */ |
496 |
if(env->err) return; |
497 |
push_val(env, val); /* Return its bound value */ |
498 |
} |
499 |
|
500 |
/* If the top element is a symbol, determine if it's bound to a |
501 |
function value, and if it is, toss the symbol and execute the |
502 |
function. */ |
503 |
extern void eval(environment *env) |
504 |
{ |
505 |
funcp in_func; |
506 |
value* temp_val; |
507 |
stackitem* iterator; |
508 |
|
509 |
eval_start: |
510 |
|
511 |
if(env->head==NULL) { |
512 |
printerr("Too Few Arguments"); |
513 |
env->err=1; |
514 |
return; |
515 |
} |
516 |
|
517 |
switch(env->head->item->type) { |
518 |
/* if it's a symbol */ |
519 |
case symb: |
520 |
rcl(env); /* get its contents */ |
521 |
if(env->err) return; |
522 |
if(env->head->item->type!=symb){ /* don't recurse symbols */ |
523 |
goto eval_start; |
524 |
} |
525 |
return; |
526 |
|
527 |
/* If it's a lone function value, run it */ |
528 |
case func: |
529 |
in_func= (funcp)(env->head->item->content.ptr); |
530 |
toss(env); |
531 |
if(env->err) return; |
532 |
return (*in_func)(env); |
533 |
|
534 |
/* If it's a list */ |
535 |
case list: |
536 |
temp_val= env->head->item; |
537 |
env->head->item->refcount++; |
538 |
toss(env); |
539 |
if(env->err) return; |
540 |
iterator= (stackitem*)temp_val->content.ptr; |
541 |
while(iterator!=NULL) { |
542 |
push_val(env, iterator->item); |
543 |
if(env->head->item->type==symb |
544 |
&& strcmp(";", ((symbol*)(env->head->item->content.ptr))->id)==0) { |
545 |
toss(env); |
546 |
if(env->err) return; |
547 |
if(iterator->next == NULL){ |
548 |
free_val(temp_val); |
549 |
goto eval_start; |
550 |
} |
551 |
eval(env); |
552 |
if(env->err) return; |
553 |
} |
554 |
iterator= iterator->next; |
555 |
} |
556 |
free_val(temp_val); |
557 |
return; |
558 |
|
559 |
default: |
560 |
return; |
561 |
} |
562 |
} |
563 |
|
564 |
/* Reverse (flip) a list */ |
565 |
extern void rev(environment *env){ |
566 |
stackitem *old_head, *new_head, *item; |
567 |
|
568 |
if((env->head)==NULL) { |
569 |
printerr("Too Few Arguments"); |
570 |
env->err=1; |
571 |
return; |
572 |
} |
573 |
|
574 |
if(env->head->item->type!=list) { |
575 |
printerr("Bad Argument Type"); |
576 |
env->err=2; |
577 |
return; |
578 |
} |
579 |
|
580 |
old_head=(stackitem *)(env->head->item->content.ptr); |
581 |
new_head=NULL; |
582 |
while(old_head != NULL){ |
583 |
item=old_head; |
584 |
old_head=old_head->next; |
585 |
item->next=new_head; |
586 |
new_head=item; |
587 |
} |
588 |
env->head->item->content.ptr=new_head; |
589 |
} |
590 |
|
591 |
/* Make a list. */ |
592 |
extern void pack(environment *env) |
593 |
{ |
594 |
stackitem *iterator, *temp; |
595 |
value *pack; |
596 |
|
597 |
iterator= env->head; |
598 |
|
599 |
if(iterator==NULL |
600 |
|| (iterator->item->type==symb |
601 |
&& ((symbol*)(iterator->item->content.ptr))->id[0]=='[')) { |
602 |
temp= NULL; |
603 |
toss(env); |
604 |
} else { |
605 |
/* Search for first delimiter */ |
606 |
while(iterator->next!=NULL |
607 |
&& (iterator->next->item->type!=symb |
608 |
|| ((symbol*)(iterator->next->item->content.ptr))->id[0]!='[')) |
609 |
iterator= iterator->next; |
610 |
|
611 |
/* Extract list */ |
612 |
temp= env->head; |
613 |
env->head= iterator->next; |
614 |
iterator->next= NULL; |
615 |
|
616 |
if(env->head!=NULL) |
617 |
toss(env); |
618 |
} |
619 |
|
620 |
/* Push list */ |
621 |
pack= malloc(sizeof(value)); |
622 |
pack->type= list; |
623 |
pack->content.ptr= temp; |
624 |
pack->refcount= 0; |
625 |
|
626 |
push_val(env, pack); |
627 |
rev(env); |
628 |
} |
629 |
|
630 |
/* Relocate elements of the list on the stack. */ |
631 |
extern void expand(environment *env) |
632 |
{ |
633 |
stackitem *temp, *new_head; |
634 |
|
635 |
/* Is top element a list? */ |
636 |
if(env->head==NULL) { |
637 |
printerr("Too Few Arguments"); |
638 |
env->err=1; |
639 |
return; |
640 |
} |
641 |
if(env->head->item->type!=list) { |
642 |
printerr("Bad Argument Type"); |
643 |
env->err=2; |
644 |
return; |
645 |
} |
646 |
|
647 |
rev(env); |
648 |
|
649 |
if(env->err) |
650 |
return; |
651 |
|
652 |
/* The first list element is the new stack head */ |
653 |
new_head= temp= env->head->item->content.ptr; |
654 |
|
655 |
env->head->item->refcount++; |
656 |
toss(env); |
657 |
|
658 |
/* Find the end of the list */ |
659 |
while(temp->next!=NULL) |
660 |
temp= temp->next; |
661 |
|
662 |
/* Connect the tail of the list with the old stack head */ |
663 |
temp->next= env->head; |
664 |
env->head= new_head; /* ...and voila! */ |
665 |
|
666 |
} |
667 |
|
668 |
/* Compares two elements by reference. */ |
669 |
extern void eq(environment *env) |
670 |
{ |
671 |
void *left, *right; |
672 |
int result; |
673 |
|
674 |
if((env->head)==NULL || env->head->next==NULL) { |
675 |
printerr("Too Few Arguments"); |
676 |
env->err=1; |
677 |
return; |
678 |
} |
679 |
|
680 |
left= env->head->item->content.ptr; |
681 |
swap(env); |
682 |
right= env->head->item->content.ptr; |
683 |
result= (left==right); |
684 |
|
685 |
toss(env); toss(env); |
686 |
push_int(env, result); |
687 |
} |
688 |
|
689 |
/* Negates the top element on the stack. */ |
690 |
extern void not(environment *env) |
691 |
{ |
692 |
int val; |
693 |
|
694 |
if((env->head)==NULL) { |
695 |
printerr("Too Few Arguments"); |
696 |
env->err=1; |
697 |
return; |
698 |
} |
699 |
|
700 |
if(env->head->item->type!=integer) { |
701 |
printerr("Bad Argument Type"); |
702 |
env->err=2; |
703 |
return; |
704 |
} |
705 |
|
706 |
val= env->head->item->content.val; |
707 |
toss(env); |
708 |
push_int(env, !val); |
709 |
} |
710 |
|
711 |
/* Compares the two top elements on the stack and return 0 if they're the |
712 |
same. */ |
713 |
extern void neq(environment *env) |
714 |
{ |
715 |
eq(env); |
716 |
not(env); |
717 |
} |
718 |
|
719 |
/* Give a symbol some content. */ |
720 |
extern void def(environment *env) |
721 |
{ |
722 |
symbol *sym; |
723 |
|
724 |
/* Needs two values on the stack, the top one must be a symbol */ |
725 |
if(env->head==NULL || env->head->next==NULL) { |
726 |
printerr("Too Few Arguments"); |
727 |
env->err=1; |
728 |
return; |
729 |
} |
730 |
|
731 |
if(env->head->item->type!=symb) { |
732 |
printerr("Bad Argument Type"); |
733 |
env->err=2; |
734 |
return; |
735 |
} |
736 |
|
737 |
/* long names are a pain */ |
738 |
sym=env->head->item->content.ptr; |
739 |
|
740 |
/* if the symbol was bound to something else, throw it away */ |
741 |
if(sym->val != NULL) |
742 |
free_val(sym->val); |
743 |
|
744 |
/* Bind the symbol to the value */ |
745 |
sym->val= env->head->next->item; |
746 |
sym->val->refcount++; /* Increase the reference counter */ |
747 |
|
748 |
toss(env); toss(env); |
749 |
} |
750 |
|
751 |
extern void clear(environment *); |
752 |
void forget_sym(symbol **); |
753 |
extern void words(environment *); |
754 |
|
755 |
/* Quit stack. */ |
756 |
extern void quit(environment *env) |
757 |
{ |
758 |
long i; |
759 |
|
760 |
clear(env); |
761 |
|
762 |
if (env->err) return; |
763 |
for(i= 0; i<HASHTBLSIZE; i++) { |
764 |
while(env->symbols[i]!= NULL) { |
765 |
forget_sym(&(env->symbols[i])); |
766 |
} |
767 |
env->symbols[i]= NULL; |
768 |
} |
769 |
|
770 |
if(env->free_string!=NULL) |
771 |
free(env->free_string); |
772 |
|
773 |
muntrace(); |
774 |
|
775 |
exit(EXIT_SUCCESS); |
776 |
} |
777 |
|
778 |
/* Clear stack */ |
779 |
extern void clear(environment *env) |
780 |
{ |
781 |
while(env->head!=NULL) |
782 |
toss(env); |
783 |
} |
784 |
|
785 |
/* List all defined words */ |
786 |
extern void words(environment *env) |
787 |
{ |
788 |
symbol *temp; |
789 |
int i; |
790 |
|
791 |
for(i= 0; i<HASHTBLSIZE; i++) { |
792 |
temp= env->symbols[i]; |
793 |
while(temp!=NULL) { |
794 |
printf("%s\n", temp->id); |
795 |
temp= temp->next; |
796 |
} |
797 |
} |
798 |
} |
799 |
|
800 |
/* Internal forget function */ |
801 |
void forget_sym(symbol **hash_entry) { |
802 |
symbol *temp; |
803 |
|
804 |
temp= *hash_entry; |
805 |
*hash_entry= (*hash_entry)->next; |
806 |
|
807 |
if(temp->val!=NULL) { |
808 |
free_val(temp->val); |
809 |
} |
810 |
free(temp->id); |
811 |
free(temp); |
812 |
} |
813 |
|
814 |
/* Forgets a symbol (remove it from the hash table) */ |
815 |
extern void forget(environment *env) |
816 |
{ |
817 |
char* sym_id; |
818 |
stackitem *stack_head= env->head; |
819 |
|
820 |
if(stack_head==NULL) { |
821 |
printerr("Too Few Arguments"); |
822 |
env->err=1; |
823 |
return; |
824 |
} |
825 |
|
826 |
if(stack_head->item->type!=symb) { |
827 |
printerr("Bad Argument Type"); |
828 |
env->err=2; |
829 |
return; |
830 |
} |
831 |
|
832 |
sym_id= ((symbol*)(stack_head->item->content.ptr))->id; |
833 |
toss(env); |
834 |
|
835 |
return forget_sym(hash(env->symbols, sym_id)); |
836 |
} |
837 |
|
838 |
/* Returns the current error number to the stack */ |
839 |
extern void errn(environment *env){ |
840 |
push_int(env, env->err); |
841 |
} |
842 |
|
843 |
extern void sx_72656164(environment*); |
844 |
|
845 |
int main(int argc, char **argv) |
846 |
{ |
847 |
environment myenv; |
848 |
|
849 |
int c; /* getopt option character */ |
850 |
|
851 |
mtrace(); |
852 |
|
853 |
init_env(&myenv); |
854 |
|
855 |
myenv.interactive = isatty(STDIN_FILENO) && isatty(STDOUT_FILENO); |
856 |
|
857 |
while ((c = getopt (argc, argv, "i")) != -1) |
858 |
switch (c) |
859 |
{ |
860 |
case 'i': |
861 |
myenv.interactive = 1; |
862 |
break; |
863 |
case '?': |
864 |
fprintf (stderr, |
865 |
"Unknown option character `\\x%x'.\n", |
866 |
optopt); |
867 |
return EX_USAGE; |
868 |
default: |
869 |
abort (); |
870 |
} |
871 |
|
872 |
if (optind < argc) { |
873 |
myenv.interactive = 0; |
874 |
myenv.inputstream= fopen(argv[optind], "r"); |
875 |
if(myenv.inputstream== NULL) { |
876 |
perror(argv[0]); |
877 |
exit (EX_NOINPUT); |
878 |
} |
879 |
} |
880 |
|
881 |
while(1) { |
882 |
if(myenv.in_string==NULL && myenv.interactive) { |
883 |
nl(); |
884 |
printstack(&myenv); |
885 |
printf("> "); |
886 |
} |
887 |
sx_72656164(&myenv); |
888 |
if(myenv.err) { |
889 |
printf("(error %d) ", myenv.err); |
890 |
if (myenv.err==4) |
891 |
return EX_NOINPUT; |
892 |
myenv.err=0; |
893 |
} else if(myenv.head!=NULL |
894 |
&& myenv.head->item->type==symb |
895 |
&& ((symbol*)(myenv.head->item->content.ptr))->id[0]==';') { |
896 |
toss(&myenv); /* No error check in main */ |
897 |
eval(&myenv); |
898 |
} |
899 |
} |
900 |
quit(&myenv); |
901 |
return EXIT_FAILURE; |
902 |
} |
903 |
|
904 |
/* + */ |
905 |
extern void sx_2b(environment *env) { |
906 |
int a, b; |
907 |
size_t len; |
908 |
char* new_string; |
909 |
value *a_val, *b_val; |
910 |
|
911 |
if((env->head)==NULL || env->head->next==NULL) { |
912 |
printerr("Too Few Arguments"); |
913 |
env->err=1; |
914 |
return; |
915 |
} |
916 |
|
917 |
if(env->head->item->type==string |
918 |
&& env->head->next->item->type==string) { |
919 |
a_val= env->head->item; |
920 |
b_val= env->head->next->item; |
921 |
a_val->refcount++; |
922 |
b_val->refcount++; |
923 |
toss(env); if(env->err) return; |
924 |
toss(env); if(env->err) return; |
925 |
len= strlen(a_val->content.ptr)+strlen(b_val->content.ptr)+1; |
926 |
new_string= malloc(len); |
927 |
strcpy(new_string, b_val->content.ptr); |
928 |
strcat(new_string, a_val->content.ptr); |
929 |
free_val(a_val); free_val(b_val); |
930 |
push_cstring(env, new_string); |
931 |
free(new_string); |
932 |
return; |
933 |
} |
934 |
|
935 |
if(env->head->item->type!=integer |
936 |
|| env->head->next->item->type!=integer) { |
937 |
printerr("Bad Argument Type"); |
938 |
env->err=2; |
939 |
return; |
940 |
} |
941 |
a=env->head->item->content.val; |
942 |
toss(env); |
943 |
if(env->err) return; |
944 |
if(env->head->item->refcount == 1) |
945 |
env->head->item->content.val += a; |
946 |
else { |
947 |
b=env->head->item->content.val; |
948 |
toss(env); |
949 |
if(env->err) return; |
950 |
push_int(env, a+b); |
951 |
} |
952 |
} |
953 |
|
954 |
/* - */ |
955 |
extern void sx_2d(environment *env) { |
956 |
int a, b; |
957 |
|
958 |
if((env->head)==NULL || env->head->next==NULL) { |
959 |
printerr("Too Few Arguments"); |
960 |
env->err=1; |
961 |
return; |
962 |
} |
963 |
|
964 |
if(env->head->item->type!=integer |
965 |
|| env->head->next->item->type!=integer) { |
966 |
printerr("Bad Argument Type"); |
967 |
env->err=2; |
968 |
return; |
969 |
} |
970 |
a=env->head->item->content.val; |
971 |
toss(env); |
972 |
if(env->err) return; |
973 |
if(env->head->item->refcount == 1) |
974 |
env->head->item->content.val -= a; |
975 |
else { |
976 |
b=env->head->item->content.val; |
977 |
toss(env); |
978 |
if(env->err) return; |
979 |
push_int(env, b-a); |
980 |
} |
981 |
} |
982 |
|
983 |
/* > */ |
984 |
extern void sx_3e(environment *env) { |
985 |
int a, b; |
986 |
|
987 |
if((env->head)==NULL || env->head->next==NULL) { |
988 |
printerr("Too Few Arguments"); |
989 |
env->err=1; |
990 |
return; |
991 |
} |
992 |
|
993 |
if(env->head->item->type!=integer |
994 |
|| env->head->next->item->type!=integer) { |
995 |
printerr("Bad Argument Type"); |
996 |
env->err=2; |
997 |
return; |
998 |
} |
999 |
a=env->head->item->content.val; |
1000 |
toss(env); |
1001 |
if(env->err) return; |
1002 |
if(env->head->item->refcount == 1) |
1003 |
env->head->item->content.val = (env->head->item->content.val > a); |
1004 |
else { |
1005 |
b=env->head->item->content.val; |
1006 |
toss(env); |
1007 |
if(env->err) return; |
1008 |
push_int(env, b>a); |
1009 |
} |
1010 |
} |
1011 |
|
1012 |
/* Return copy of a value */ |
1013 |
value *copy_val(value *old_value){ |
1014 |
stackitem *old_item, *new_item, *prev_item; |
1015 |
|
1016 |
value *new_value=malloc(sizeof(value)); |
1017 |
|
1018 |
new_value->type=old_value->type; |
1019 |
new_value->refcount=0; /* This is increased if/when this |
1020 |
value is referenced somewhere, like |
1021 |
in a stack item or a variable */ |
1022 |
switch(old_value->type){ |
1023 |
case integer: |
1024 |
new_value->content.val=old_value->content.val; |
1025 |
break; |
1026 |
case string: |
1027 |
(char *)(new_value->content.ptr) |
1028 |
= strdup((char *)(old_value->content.ptr)); |
1029 |
break; |
1030 |
case func: |
1031 |
case symb: |
1032 |
new_value->content.ptr=old_value->content.ptr; |
1033 |
break; |
1034 |
case list: |
1035 |
new_value->content.ptr=NULL; |
1036 |
|
1037 |
prev_item=NULL; |
1038 |
old_item=(stackitem *)(old_value->content.ptr); |
1039 |
|
1040 |
while(old_item != NULL) { /* While list is not empty */ |
1041 |
new_item= malloc(sizeof(stackitem)); |
1042 |
new_item->item=copy_val(old_item->item); /* recurse */ |
1043 |
new_item->next=NULL; |
1044 |
if(prev_item != NULL) /* If this wasn't the first item */ |
1045 |
prev_item->next=new_item; /* point the previous item to the |
1046 |
new item */ |
1047 |
else |
1048 |
new_value->content.ptr=new_item; |
1049 |
old_item=old_item->next; |
1050 |
prev_item=new_item; |
1051 |
} |
1052 |
break; |
1053 |
} |
1054 |
return new_value; |
1055 |
} |
1056 |
|
1057 |
/* "dup"; duplicates an item on the stack */ |
1058 |
extern void sx_647570(environment *env) { |
1059 |
if((env->head)==NULL) { |
1060 |
printerr("Too Few Arguments"); |
1061 |
env->err=1; |
1062 |
return; |
1063 |
} |
1064 |
push_val(env, copy_val(env->head->item)); |
1065 |
} |
1066 |
|
1067 |
/* "if", If-Then */ |
1068 |
extern void sx_6966(environment *env) { |
1069 |
|
1070 |
int truth; |
1071 |
|
1072 |
if((env->head)==NULL || env->head->next==NULL) { |
1073 |
printerr("Too Few Arguments"); |
1074 |
env->err=1; |
1075 |
return; |
1076 |
} |
1077 |
|
1078 |
if(env->head->next->item->type != integer) { |
1079 |
printerr("Bad Argument Type"); |
1080 |
env->err=2; |
1081 |
return; |
1082 |
} |
1083 |
|
1084 |
swap(env); |
1085 |
if(env->err) return; |
1086 |
|
1087 |
truth=env->head->item->content.val; |
1088 |
|
1089 |
toss(env); |
1090 |
if(env->err) return; |
1091 |
|
1092 |
if(truth) |
1093 |
eval(env); |
1094 |
else |
1095 |
toss(env); |
1096 |
} |
1097 |
|
1098 |
/* If-Then-Else */ |
1099 |
extern void ifelse(environment *env) { |
1100 |
|
1101 |
int truth; |
1102 |
|
1103 |
if((env->head)==NULL || env->head->next==NULL |
1104 |
|| env->head->next->next==NULL) { |
1105 |
printerr("Too Few Arguments"); |
1106 |
env->err=1; |
1107 |
return; |
1108 |
} |
1109 |
|
1110 |
if(env->head->next->next->item->type != integer) { |
1111 |
printerr("Bad Argument Type"); |
1112 |
env->err=2; |
1113 |
return; |
1114 |
} |
1115 |
|
1116 |
rot(env); |
1117 |
if(env->err) return; |
1118 |
|
1119 |
truth=env->head->item->content.val; |
1120 |
|
1121 |
toss(env); |
1122 |
if(env->err) return; |
1123 |
|
1124 |
if(!truth) |
1125 |
swap(env); |
1126 |
if(env->err) return; |
1127 |
|
1128 |
toss(env); |
1129 |
if(env->err) return; |
1130 |
|
1131 |
eval(env); |
1132 |
} |
1133 |
|
1134 |
/* while */ |
1135 |
extern void sx_7768696c65(environment *env) { |
1136 |
|
1137 |
int truth; |
1138 |
value *loop, *test; |
1139 |
|
1140 |
if((env->head)==NULL || env->head->next==NULL) { |
1141 |
printerr("Too Few Arguments"); |
1142 |
env->err=1; |
1143 |
return; |
1144 |
} |
1145 |
|
1146 |
loop= env->head->item; |
1147 |
loop->refcount++; |
1148 |
toss(env); if(env->err) return; |
1149 |
|
1150 |
test= env->head->item; |
1151 |
test->refcount++; |
1152 |
toss(env); if(env->err) return; |
1153 |
|
1154 |
do { |
1155 |
push_val(env, test); |
1156 |
eval(env); |
1157 |
|
1158 |
if(env->head->item->type != integer) { |
1159 |
printerr("Bad Argument Type"); |
1160 |
env->err=2; |
1161 |
return; |
1162 |
} |
1163 |
|
1164 |
truth= env->head->item->content.val; |
1165 |
toss(env); if(env->err) return; |
1166 |
|
1167 |
if(truth) { |
1168 |
push_val(env, loop); |
1169 |
eval(env); |
1170 |
} else { |
1171 |
toss(env); |
1172 |
} |
1173 |
|
1174 |
} while(truth); |
1175 |
|
1176 |
free_val(test); |
1177 |
free_val(loop); |
1178 |
} |
1179 |
|
1180 |
/* "for"; For-loop */ |
1181 |
extern void sx_666f72(environment *env) { |
1182 |
|
1183 |
value *loop, *foo; |
1184 |
stackitem *iterator; |
1185 |
|
1186 |
if((env->head)==NULL || env->head->next==NULL) { |
1187 |
printerr("Too Few Arguments"); |
1188 |
env->err=1; |
1189 |
return; |
1190 |
} |
1191 |
|
1192 |
if(env->head->next->item->type != list) { |
1193 |
printerr("Bad Argument Type"); |
1194 |
env->err=2; |
1195 |
return; |
1196 |
} |
1197 |
|
1198 |
loop= env->head->item; |
1199 |
loop->refcount++; |
1200 |
toss(env); if(env->err) return; |
1201 |
|
1202 |
foo= env->head->item; |
1203 |
foo->refcount++; |
1204 |
toss(env); if(env->err) return; |
1205 |
|
1206 |
iterator= foo->content.ptr; |
1207 |
|
1208 |
while(iterator!=NULL) { |
1209 |
push_val(env, iterator->item); |
1210 |
push_val(env, loop); |
1211 |
eval(env); if(env->err) return; |
1212 |
iterator= iterator->next; |
1213 |
} |
1214 |
|
1215 |
free_val(loop); |
1216 |
free_val(foo); |
1217 |
} |
1218 |
|
1219 |
/* 'to' */ |
1220 |
extern void to(environment *env) { |
1221 |
int i, start, ending; |
1222 |
stackitem *temp_head; |
1223 |
value *temp_val; |
1224 |
|
1225 |
if((env->head)==NULL || env->head->next==NULL) { |
1226 |
printerr("Too Few Arguments"); |
1227 |
env->err=1; |
1228 |
return; |
1229 |
} |
1230 |
|
1231 |
if(env->head->item->type!=integer |
1232 |
|| env->head->next->item->type!=integer) { |
1233 |
printerr("Bad Argument Type"); |
1234 |
env->err=2; |
1235 |
return; |
1236 |
} |
1237 |
|
1238 |
ending= env->head->item->content.val; |
1239 |
toss(env); if(env->err) return; |
1240 |
start= env->head->item->content.val; |
1241 |
toss(env); if(env->err) return; |
1242 |
|
1243 |
temp_head= env->head; |
1244 |
env->head= NULL; |
1245 |
|
1246 |
if(ending>=start) { |
1247 |
for(i= ending; i>=start; i--) |
1248 |
push_int(env, i); |
1249 |
} else { |
1250 |
for(i= ending; i<=start; i++) |
1251 |
push_int(env, i); |
1252 |
} |
1253 |
|
1254 |
temp_val= malloc(sizeof(value)); |
1255 |
temp_val->content.ptr= env->head; |
1256 |
temp_val->refcount= 0; |
1257 |
temp_val->type= list; |
1258 |
env->head= temp_head; |
1259 |
push_val(env, temp_val); |
1260 |
} |
1261 |
|
1262 |
/* Read a string */ |
1263 |
extern void readline(environment *env) { |
1264 |
char in_string[101]; |
1265 |
|
1266 |
if(fgets(in_string, 100, env->inputstream)==NULL) |
1267 |
push_cstring(env, ""); |
1268 |
else |
1269 |
push_cstring(env, in_string); |
1270 |
} |
1271 |
|
1272 |
/* "read"; Read a value and place on stack */ |
1273 |
extern void sx_72656164(environment *env) { |
1274 |
const char symbform[]= "%[a-zA-Z0-9!$%*+./:<=>?@^_~-]%n"; |
1275 |
const char strform[]= "\"%[^\"]\"%n"; |
1276 |
const char intform[]= "%i%n"; |
1277 |
const char blankform[]= "%*[ \t]%n"; |
1278 |
const char ebrackform[]= "%*1[]]%n"; |
1279 |
const char semicform[]= "%*1[;]%n"; |
1280 |
const char bbrackform[]= "%*1[[]%n"; |
1281 |
|
1282 |
int itemp, readlength= -1; |
1283 |
static int depth= 0; |
1284 |
char *match; |
1285 |
size_t inlength; |
1286 |
|
1287 |
if(env->in_string==NULL) { |
1288 |
if(depth > 0 && env->interactive) { |
1289 |
printf("]> "); |
1290 |
} |
1291 |
readline(env); if(env->err) return; |
1292 |
|
1293 |
if(((char *)(env->head->item->content.ptr))[0]=='\0'){ |
1294 |
env->err= 4; /* EOF */ |
1295 |
return; |
1296 |
} |
1297 |
|
1298 |
env->in_string= malloc(strlen(env->head->item->content.ptr)+1); |
1299 |
env->free_string= env->in_string; /* Save the original pointer */ |
1300 |
strcpy(env->in_string, env->head->item->content.ptr); |
1301 |
toss(env); if(env->err) return; |
1302 |
} |
1303 |
|
1304 |
inlength= strlen(env->in_string)+1; |
1305 |
match= malloc(inlength); |
1306 |
|
1307 |
if(sscanf(env->in_string, blankform, &readlength)!=EOF |
1308 |
&& readlength != -1) { |
1309 |
; |
1310 |
} else if(sscanf(env->in_string, intform, &itemp, &readlength) != EOF |
1311 |
&& readlength != -1) { |
1312 |
push_int(env, itemp); |
1313 |
} else if(sscanf(env->in_string, strform, match, &readlength) != EOF |
1314 |
&& readlength != -1) { |
1315 |
push_cstring(env, match); |
1316 |
} else if(sscanf(env->in_string, symbform, match, &readlength) != EOF |
1317 |
&& readlength != -1) { |
1318 |
push_sym(env, match); |
1319 |
} else if(sscanf(env->in_string, ebrackform, &readlength) != EOF |
1320 |
&& readlength != -1) { |
1321 |
pack(env); if(env->err) return; |
1322 |
if(depth != 0) depth--; |
1323 |
} else if(sscanf(env->in_string, semicform, &readlength) != EOF |
1324 |
&& readlength != -1) { |
1325 |
push_sym(env, ";"); |
1326 |
} else if(sscanf(env->in_string, bbrackform, &readlength) != EOF |
1327 |
&& readlength != -1) { |
1328 |
push_sym(env, "["); |
1329 |
depth++; |
1330 |
} else { |
1331 |
free(env->free_string); |
1332 |
env->in_string = env->free_string = NULL; |
1333 |
} |
1334 |
if ( env->in_string != NULL) { |
1335 |
env->in_string += readlength; |
1336 |
} |
1337 |
|
1338 |
free(match); |
1339 |
|
1340 |
if(depth) |
1341 |
return sx_72656164(env); |
1342 |
} |