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revision 1.8 by masse, Tue Jan 8 14:17:33 2002 UTC revision 1.130 by masse, Mon Aug 4 14:32:27 2003 UTC
# Line 1  Line 1 
1  /* printf */  /* -*- coding: utf-8; -*- */
2  #include <stdio.h>  /*
3  /* EXIT_SUCCESS */      stack - an interactive interpreter for a stack-based language
4  #include <stdlib.h>      Copyright (C) 2002  Mats Alritzson and Teddy Hogeborn
 /* NULL */  
 #include <stddef.h>  
 /* dlopen, dlsym, dlerror */  
 #include <dlfcn.h>  
5    
6  #define HASHTBLSIZE 65536      This program is free software; you can redistribute it and/or modify
7        it under the terms of the GNU General Public License as published by
8        the Free Software Foundation; either version 2 of the License, or
9        (at your option) any later version.
10    
11  typedef struct stack_item      This program is distributed in the hope that it will be useful,
12  {      but WITHOUT ANY WARRANTY; without even the implied warranty of
13    enum {value, string, ref, func, symbol, list} type;      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14    union {      GNU General Public License for more details.
     void* ptr;  
     int val;  
   } content;  
15    
16    char* id;      You should have received a copy of the GNU General Public License
17    struct stack_item* next;      along with this program; if not, write to the Free Software
18  } stackitem;      Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19    
20        Authors: Mats Alritzson <masse@fukt.bth.se>
21                 Teddy Hogeborn <teddy@fukt.bth.se>
22    */
23    
24  typedef stackitem* hashtbl[HASHTBLSIZE];  #include "stack.h"
 typedef void (*funcp)(stackitem**);  
25    
26  void init_hashtbl(hashtbl out_hash)  /* Initialize a newly created environment */
27    void init_env(environment *env)
28  {  {
29    long i;    int i;
30    
31      env->gc_limit= 400000;
32      env->gc_count= 0;
33      env->gc_ref= NULL;
34    
35      env->head= new_val(env);
36    for(i= 0; i<HASHTBLSIZE; i++)    for(i= 0; i<HASHTBLSIZE; i++)
37      out_hash[i]= NULL;      env->symbols[i]= NULL;
38      env->err= 0;
39      env->in_string= NULL;
40      env->free_string= NULL;
41      env->inputstream= stdin;
42      env->interactive= 1;
43    }
44    
45    void printerr(const char* in_string)
46    {
47      fprintf(stderr, "Err: %s\n", in_string);
48  }  }
49    
50  stackitem** hash(hashtbl in_hashtbl, const char* in_string)  /* Returns a pointer to a pointer to an element in the hash table. */
51    symbol **hash(hashtbl in_hashtbl, const char *in_string)
52  {  {
53    long i= 0;    int i= 0;
54    unsigned long out_hash= 0;    unsigned int out_hash= 0;
55    char key= 0;    char key= '\0';
56    stackitem** position;    symbol **position;
57        
58    while(1){    while(1){                     /* Hash in_string */
59      key= in_string[i++];      key= in_string[i++];
60      if(key=='\0')      if(key=='\0')
61        break;        break;
# Line 51  stackitem** hash(hashtbl in_hashtbl, con Line 66  stackitem** hash(hashtbl in_hashtbl, con
66    position= &(in_hashtbl[out_hash]);    position= &(in_hashtbl[out_hash]);
67    
68    while(1){    while(1){
69      if(*position==NULL)      if(*position==NULL)         /* If empty */
70        return position;        return position;
71            
72      if(strcmp(in_string, (*position)->id)==0)      if(strcmp(in_string, (*position)->id)==0) /* If match */
73        return position;        return position;
74    
75      position= &((*position)->next);      position= &((*position)->next); /* Try next */
76    }    }
77  }  }
78    
79    /* Create new value */
80  int push(stackitem** stack_head, stackitem* in_item)  value* new_val(environment *env)
81  {  {
82    in_item->next= *stack_head;    value *nval= malloc(sizeof(value));
83    *stack_head= in_item;    stackitem *nitem= malloc(sizeof(stackitem));
84    return 1;  
85      assert(nval != NULL);
86      assert(nitem != NULL);
87    
88      nval->content.ptr= NULL;
89      nval->type= empty;
90    
91      nitem->item= nval;
92      nitem->next= env->gc_ref;
93    
94      env->gc_ref= nitem;
95    
96      env->gc_count += sizeof(value);
97      nval->gc.flag.mark= 0;
98      nval->gc.flag.protect= 0;
99    
100      return nval;
101  }  }
102    
103  int push_val(stackitem** stack_head, int in_val)  
104    /* Mark values recursively.
105       Marked values are not collected by the GC. */
106    inline void gc_mark(value *val)
107  {  {
108    stackitem* new_item= malloc(sizeof(stackitem));    if(val==NULL || val->gc.flag.mark)
109    new_item->content.val= in_val;      return;
110    new_item->type= value;  
111      val->gc.flag.mark= 1;
112    
113    push(stack_head, new_item);    if(val->type==tcons) {
114    return 1;      gc_mark(CAR(val));
115        gc_mark(CDR(val));
116      }
117  }  }
118    
119  int push_cstring(stackitem** stack_head, const char* in_string)  
120    /* Start GC */
121    extern void gc_init(environment *env)
122  {  {
123    stackitem* new_item= malloc(sizeof(stackitem));    stackitem *new_head= NULL, *titem;
124    new_item->content.ptr= malloc(strlen(in_string)+1);    symbol *tsymb;
125    strcpy(new_item->content.ptr, in_string);    int i;
126    new_item->type= string;  
127      if(env->interactive)
128        printf("Garbage collecting.");
129    
130      /* Mark values on stack */
131      gc_mark(env->head);
132    
133      if(env->interactive)
134        printf(".");
135    
136    
137    push(stack_head, new_item);    /* Mark values in hashtable */
138    return 1;    for(i= 0; i<HASHTBLSIZE; i++)
139        for(tsymb= env->symbols[i]; tsymb!=NULL; tsymb= tsymb->next)
140          if (tsymb->val != NULL)
141            gc_mark(tsymb->val);
142    
143    
144      if(env->interactive)
145        printf(".");
146    
147      env->gc_count= 0;
148    
149      while(env->gc_ref!=NULL) {    /* Sweep unused values */
150    
151        if(!(env->gc_ref->item->gc.no_gc)){ /* neither mark nor protect */
152    
153          /* Remove content */
154          switch(env->gc_ref->item->type){
155          case string:
156            free(env->gc_ref->item->content.string);
157            break;
158          case tcons:
159            free(env->gc_ref->item->content.c);
160            break;
161          case port:
162          case empty:
163          case integer:
164          case tfloat:
165          case func:
166          case symb:
167            /* Symbol strings are freed when walking the hash table */
168            break;
169          }
170    
171          free(env->gc_ref->item);  /* Remove from gc_ref */
172          titem= env->gc_ref->next;
173          free(env->gc_ref);        /* Remove value */
174          env->gc_ref= titem;
175          continue;
176        }
177    #ifdef DEBUG
178        printf("Kept value (%p)", env->gc_ref->item);
179        if(env->gc_ref->item->gc.flag.mark)
180          printf(" (marked)");
181        if(env->gc_ref->item->gc.flag.protect)
182          printf(" (protected)");
183        switch(env->gc_ref->item->type){
184        case integer:
185          printf(" integer: %d", env->gc_ref->item->content.i);
186          break;
187        case func:
188          printf(" func: %p", env->gc_ref->item->content.func);
189          break;
190        case symb:
191          printf(" symb: %s", env->gc_ref->item->content.sym->id);
192          break;
193        case tcons:
194          printf(" tcons: %p\t%p", CAR(env->gc_ref->item),
195                 CDR(env->gc_ref->item));
196          break;
197        default:
198          printf(" <unknown %d>", (env->gc_ref->item->type));
199        }
200        printf("\n");
201    #endif /* DEBUG */
202    
203        /* Keep values */    
204        env->gc_count += sizeof(value);
205        if(env->gc_ref->item->type==string)
206          env->gc_count += strlen(env->gc_ref->item->content.string)+1;
207        
208        titem= env->gc_ref->next;
209        env->gc_ref->next= new_head;
210        new_head= env->gc_ref;
211        new_head->item->gc.flag.mark= 0;
212        env->gc_ref= titem;
213      }
214    
215      if (env->gc_limit < env->gc_count*2)
216        env->gc_limit= env->gc_count*2;
217    
218      env->gc_ref= new_head;
219    
220      if(env->interactive)
221        printf("done (%d bytes still allocated)\n", env->gc_count);
222    
223    }
224    
225    inline void gc_maybe(environment *env)
226    {
227      if(env->gc_count < env->gc_limit)
228        return;
229      else
230        return gc_init(env);
231  }  }
232    
233  int mk_hashentry(hashtbl in_hashtbl, stackitem* in_item, const char* id)  /* Protect values from GC */
234    void protect(value *val)
235  {  {
236    in_item->id= malloc(strlen(id)+1);    if(val==NULL || val->gc.flag.protect)
237        return;
238    
239    strcpy(in_item->id, id);    val->gc.flag.protect= 1;
   push(hash(in_hashtbl, id), in_item);  
240    
241    return 1;    if(val->type==tcons) {
242        protect(CAR(val));
243        protect(CDR(val));
244      }
245  }  }
246    
247  void def_func(hashtbl in_hashtbl, funcp in_func, const char* id)  /* Unprotect values from GC */
248    void unprotect(value *val)
249  {  {
250    stackitem* temp= malloc(sizeof(stackitem));    if(val==NULL || !(val->gc.flag.protect))
251        return;
252    
253    temp->type= func;    val->gc.flag.protect= 0;
   temp->content.ptr= in_func;  
254    
255    mk_hashentry(in_hashtbl, temp, id);    if(val->type==tcons) {
256        unprotect(CAR(val));
257        unprotect(CDR(val));
258      }
259  }  }
260    
261  void def_sym(hashtbl in_hashtbl, const char* id)  /* Push a value onto the stack */
262    void push_val(environment *env, value *val)
263  {  {
264    stackitem* temp= malloc(sizeof(stackitem));    value *new_value= new_val(env);
     
   temp->type= symbol;  
265    
266    mk_hashentry(in_hashtbl, temp, id);    new_value->content.c= malloc(sizeof(pair));
267      assert(new_value->content.c!=NULL);
268      env->gc_count += sizeof(pair);
269      new_value->type= tcons;
270      CAR(new_value)= val;
271      CDR(new_value)= env->head;
272      env->head= new_value;
273  }  }
274    
275  int push_ref(stackitem** stack_head, hashtbl in_hash, const char* in_string)  /* Push an integer onto the stack */
276    void push_int(environment *env, int in_val)
277  {  {
278    static void* handle= NULL;    value *new_value= new_val(env);
279    void* symbol;    
280      new_value->content.i= in_val;
281      new_value->type= integer;
282    
283    stackitem* new_item= malloc(sizeof(stackitem));    push_val(env, new_value);
284    new_item->content.ptr= *hash(in_hash, in_string);  }
   new_item->type= ref;  
285    
286    if(handle==NULL)  /* Push a floating point number onto the stack */
287      handle= dlopen(NULL, RTLD_LAZY);  void push_float(environment *env, float in_val)
288    {
289      value *new_value= new_val(env);
290    
291    if(new_item->content.ptr==NULL) {    new_value->content.f= in_val;
292      symbol= dlsym(handle, in_string);    new_value->type= tfloat;
     if(dlerror()==NULL)  
       def_func(in_hash, symbol, in_string);  
     else  
       def_sym(in_hash, in_string);  
         
     new_item->content.ptr= *hash(in_hash, in_string);  
     new_item->type= ref;  
   }  
293    
294    push(stack_head, new_item);    push_val(env, new_value);
   return 1;  
295  }  }
296    
297  extern void toss(stackitem** stack_head)  /* Copy a string onto the stack. */
298    void push_cstring(environment *env, const char *in_string)
299  {  {
300    stackitem* temp= *stack_head;    value *new_value= new_val(env);
301      int length= strlen(in_string)+1;
302    
303    if((*stack_head)==NULL)    new_value->content.string= malloc(length);
304      return;    assert(new_value != NULL);
305        env->gc_count += length;
306    if((*stack_head)->type==string)    strcpy(new_value->content.string, in_string);
307      free((*stack_head)->content.ptr);    new_value->type= string;
308    
309    *stack_head= (*stack_head)->next;    push_val(env, new_value);
   free(temp);  
310  }  }
311    
312  extern void nl()  /* Mangle a symbol name to a valid C identifier name */
313    char *mangle_str(const char *old_string)
314  {  {
315    printf("\n");    char validchars[]= "0123456789abcdef";
316      char *new_string, *current;
317    
318      new_string= malloc((strlen(old_string)*2)+4);
319      assert(new_string != NULL);
320      strcpy(new_string, "sx_");    /* Stack eXternal */
321      current= new_string+3;
322      while(old_string[0] != '\0'){
323        current[0]= validchars[(unsigned char)(old_string[0])/16];
324        current[1]= validchars[(unsigned char)(old_string[0])%16];
325        current+= 2;
326        old_string++;
327      }
328      current[0]= '\0';
329    
330      return new_string;            /* The caller must free() it */
331  }  }
332    
333  void prin(stackitem** stack_head)  extern void mangle(environment *env)
334  {  {
335    if((*stack_head)==NULL)    char *new_string;
336    
337      if(env->head->type==empty) {
338        printerr("Too Few Arguments");
339        env->err= 1;
340        return;
341      }
342    
343      if(CAR(env->head)->type!=string) {
344        printerr("Bad Argument Type");
345        env->err= 2;
346      return;      return;
347      }
348    
349      new_string= mangle_str(CAR(env->head)->content.string);
350    
351      toss(env);
352      if(env->err) return;
353    
354      push_cstring(env, new_string);
355    }
356    
357    /* Push a symbol onto the stack. */
358    void push_sym(environment *env, const char *in_string)
359    {
360      value *new_value;             /* A new symbol value */
361      /* ...which might point to... */
362      symbol **new_symbol;          /* (if needed) A new actual symbol */
363      /* ...which, if possible, will be bound to... */
364      value *new_fvalue;            /* (if needed) A new function value */
365      /* ...which will point to... */
366      void *funcptr;                /* A function pointer */
367    
368      static void *handle= NULL;    /* Dynamic linker handle */
369      const char *dlerr;            /* Dynamic linker error */
370      char *mangled;                /* Mangled function name */
371    
372      new_value= new_val(env);
373      protect(new_value);
374      new_fvalue= new_val(env);
375      protect(new_fvalue);
376    
377      /* The new value is a symbol */
378      new_value->type= symb;
379    
380      /* Look up the symbol name in the hash table */
381      new_symbol= hash(env->symbols, in_string);
382      new_value->content.sym= *new_symbol;
383    
384      if(*new_symbol==NULL) { /* If symbol was undefined */
385    
386        /* Create a new symbol */
387        (*new_symbol)= malloc(sizeof(symbol));
388        assert((*new_symbol) != NULL);
389        (*new_symbol)->val= NULL;   /* undefined value */
390        (*new_symbol)->next= NULL;
391        (*new_symbol)->id= malloc(strlen(in_string)+1);
392        assert((*new_symbol)->id != NULL);
393        strcpy((*new_symbol)->id, in_string);
394    
395        /* Intern the new symbol in the hash table */
396        new_value->content.sym= *new_symbol;
397    
398        /* Try to load the symbol name as an external function, to see if
399           we should bind the symbol to a new function pointer value */
400        if(handle==NULL)            /* If no handle */
401          handle= dlopen(NULL, RTLD_LAZY);
402    
403        mangled= mangle_str(in_string); /* mangle the name */
404        funcptr= dlsym(handle, mangled); /* and try to find it */
405    
406        dlerr= dlerror();
407        if(dlerr != NULL) {         /* If no function was found */
408          funcptr= dlsym(handle, in_string); /* Get function pointer */
409          dlerr= dlerror();
410        }
411    
412        if(dlerr==NULL) {           /* If a function was found */
413          new_fvalue->type= func;   /* The new value is a function pointer */
414          new_fvalue->content.func= funcptr; /* Store function pointer */
415          (*new_symbol)->val= new_fvalue; /* Bind the symbol to the new
416                                             function value */
417        }
418    
419        free(mangled);
420      }
421    
422      push_val(env, new_value);
423      unprotect(new_value); unprotect(new_fvalue);
424    }
425    
426    switch((*stack_head)->type) {  /* Print a value */
427    case value:  void print_val(environment *env, value *val, int noquote, stackitem *stack, FILE *stream)
428      printf("%d", (*stack_head)->content.val);  {
429      stackitem *titem, *tstack;
430      int depth;
431    
432      switch(val->type) {
433      case empty:
434        if(fprintf(stream, "[]") < 0){
435          perror("print_val");
436          env->err= 5;
437          return;
438        }
439        break;
440      case integer:
441        if(fprintf(stream, "%d", val->content.i) < 0){
442          perror("print_val");
443          env->err= 5;
444          return;
445        }
446        break;
447      case tfloat:
448        if(fprintf(stream, "%f", val->content.f) < 0){
449          perror("print_val");
450          env->err= 5;
451          return;
452        }
453      break;      break;
454    case string:    case string:
455      printf("%s", (char*)(*stack_head)->content.ptr);      if(noquote){
456          if(fprintf(stream, "%s", val->content.string) < 0){
457            perror("print_val");
458            env->err= 5;
459            return;
460          }
461        } else {                    /* quote */
462          if(fprintf(stream, "\"%s\"", val->content.string) < 0){
463            perror("print_val");
464            env->err= 5;
465            return;
466          }
467        }
468        break;
469      case symb:
470        if(fprintf(stream, "%s", val->content.sym->id) < 0){
471          perror("print_val");
472          env->err= 5;
473          return;
474        }
475        break;
476      case func:
477        if(fprintf(stream, "#<function %p>", val->content.func) < 0){
478          perror("print_val");
479          env->err= 5;
480          return;
481        }
482      break;      break;
483    case ref:    case port:
484      printf("%s", ((stackitem*)(*stack_head)->content.ptr)->id);      if(fprintf(stream, "#<port %p>", val->content.p) < 0){
485          perror("print_val");
486          env->err= 5;
487          return;
488        }
489      break;      break;
490    case symbol:    case tcons:
491    default:      if(fprintf(stream, "[ ") < 0){
492      printf("%p", (*stack_head)->content.ptr);        perror("print_val");
493          env->err= 5;
494          return;
495        }
496        tstack= stack;
497        do {
498          titem=malloc(sizeof(stackitem));
499          assert(titem != NULL);
500          titem->item=val;
501          titem->next=tstack;
502          tstack=titem;             /* Put it on the stack */
503          /* Search a stack of values being printed to see if we are already
504             printing this value */
505          titem=tstack;
506          depth=0;
507          while(titem != NULL && titem->item != CAR(val)){
508            titem=titem->next;
509            depth++;
510          }
511          if(titem != NULL){        /* If we found it on the stack, */
512            if(fprintf(stream, "#%d#", depth) < 0){ /* print a depth reference */
513              perror("print_val");
514              env->err= 5;
515              free(titem);
516              return;
517            }
518          } else {
519            print_val(env, CAR(val), noquote, tstack, stream);
520          }
521          val= CDR(val);
522          switch(val->type){
523          case empty:
524            break;
525          case tcons:
526            /* Search a stack of values being printed to see if we are already
527               printing this value */
528            titem=tstack;
529            depth=0;
530            while(titem != NULL && titem->item != val){
531              titem=titem->next;
532              depth++;
533            }
534            if(titem != NULL){      /* If we found it on the stack, */
535              if(fprintf(stream, " . #%d#", depth) < 0){ /* print a depth reference */
536                perror("print_val");
537                env->err= 5;
538                goto printval_end;
539              }
540            } else {
541              if(fprintf(stream, " ") < 0){
542                perror("print_val");
543                env->err= 5;
544                goto printval_end;
545              }
546            }
547            break;
548          default:
549            if(fprintf(stream, " . ") < 0){ /* Improper list */
550              perror("print_val");
551              env->err= 5;
552              goto printval_end;
553            }
554            print_val(env, val, noquote, tstack, stream);
555          }
556        } while(val->type == tcons && titem == NULL);
557    
558      printval_end:
559    
560        titem=tstack;
561        while(titem != stack){
562          tstack=titem->next;
563          free(titem);
564          titem=tstack;
565        }
566    
567        if(! (env->err)){
568          if(fprintf(stream, " ]") < 0){
569            perror("print_val");
570            env->err= 5;
571          }
572        }
573      break;      break;
574    }    }
575  }  }
576    
577  extern void print(stackitem** stack_head)  /* Swap the two top elements on the stack. */
578    extern void swap(environment *env)
579  {  {
580    prin(stack_head);    value *temp= env->head;
581    toss(stack_head);    
582  }    if(env->head->type == empty || CDR(env->head)->type == empty) {
583        printerr("Too Few Arguments");
584        env->err=1;
585        return;
586      }
587    
588  /* print_stack(stack); */    env->head= CDR(env->head);
589  void print_st(stackitem* stack_head, long counter)    CDR(temp)= CDR(env->head);
590  {    CDR(env->head)= temp;
591    if(stack_head->next != NULL)  }
592      print_st(stack_head->next, counter+1);  
593    /* Recall a value from a symbol, if bound */
594    extern void rcl(environment *env)
595    {
596      value *val;
597    
598      if(env->head->type==empty) {
599        printerr("Too Few Arguments");
600        env->err= 1;
601        return;
602      }
603    
604    printf("%ld: ", counter);    if(CAR(env->head)->type!=symb) {
605    prin(&stack_head);      printerr("Bad Argument Type");
606    nl();      env->err= 2;
607  }      return;
608      }
609    
610  extern void printstack(stackitem** stack_head)    val= CAR(env->head)->content.sym->val;
611  {    if(val == NULL){
612    if(*stack_head != NULL) {      printerr("Unbound Variable");
613      print_st(*stack_head, 1);      env->err= 3;
614      printf("\n");      return;
615    }    }
616      push_val(env, val);           /* Return the symbol's bound value */
617      swap(env);
618      if(env->err) return;
619      toss(env);                    /* toss the symbol */
620      if(env->err) return;
621  }  }
622    
623    
624  extern void eval(stackitem** stack_head)  /* If the top element is a symbol, determine if it's bound to a
625       function value, and if it is, toss the symbol and execute the
626       function. */
627    extern void eval(environment *env)
628  {  {
629    funcp in_func;    funcp in_func;
630      value* temp_val;
631      value* iterator;
632    
633     eval_start:
634    
635      gc_maybe(env);
636    
637    if((*stack_head)==NULL || (*stack_head)->type!=ref)    if(env->head->type==empty) {
638        printerr("Too Few Arguments");
639        env->err= 1;
640      return;      return;
641      }
642    
643    if(((stackitem*)(*stack_head)->content.ptr)->type==func) {    switch(CAR(env->head)->type) {
644      in_func= (funcp)((stackitem*)(*stack_head)->content.ptr)->content.ptr;      /* if it's a symbol */
645      toss(stack_head);    case symb:
646      (*in_func)(stack_head);      rcl(env);                   /* get its contents */
647        if(env->err) return;
648        if(CAR(env->head)->type!=symb){ /* don't recurse symbols */
649          goto eval_start;
650        }
651        return;
652    
653        /* If it's a lone function value, run it */
654      case func:
655        in_func= CAR(env->head)->content.func;
656        toss(env);
657        if(env->err) return;
658        return in_func(env);
659    
660        /* If it's a list */
661      case tcons:
662        temp_val= CAR(env->head);
663        protect(temp_val);
664    
665        toss(env); if(env->err) return;
666        iterator= temp_val;
667        
668        while(iterator->type != empty) {
669          push_val(env, CAR(iterator));
670          
671          if(CAR(env->head)->type==symb
672             && CAR(env->head)->content.sym->id[0]==';') {
673            toss(env);
674            if(env->err) return;
675            
676            if(CDR(iterator)->type == empty){
677              goto eval_start;
678            }
679            eval(env);
680            if(env->err) return;
681          }
682          if (CDR(iterator)->type == empty || CDR(iterator)->type == tcons)
683            iterator= CDR(iterator);
684          else {
685            printerr("Bad Argument Type"); /* Improper list */
686            env->err= 2;
687            return;
688          }
689        }
690        unprotect(temp_val);
691        return;
692    
693      case empty:
694        toss(env);
695      case integer:
696      case tfloat:
697      case string:
698      case port:
699      return;      return;
700    }    }
701  }  }
702    
703  int stack_read(stackitem** stack_head, hashtbl in_hash, char* in_line)  /* List all defined words */
704    extern void words(environment *env)
705  {  {
706    char *temp, *rest;    symbol *temp;
707    int itemp;    int i;
708    size_t inlength= strlen(in_line)+1;    
709    int convert= 0;    for(i= 0; i<HASHTBLSIZE; i++) {
710        temp= env->symbols[i];
711    temp= malloc(inlength);      while(temp!=NULL) {
712    rest= malloc(inlength);  #ifdef DEBUG
713          if (temp->val != NULL && temp->val->gc.flag.protect)
714            printf("(protected) ");
715    #endif /* DEBUG */
716          printf("%s ", temp->id);
717          temp= temp->next;
718        }
719      }
720    }
721    
722    if((convert= sscanf(in_line, "\"%[^\"\n\r]\" %[^\n\r]", temp, rest)) >= 1)  /* Quit stack. */
723      push_cstring(stack_head, temp);  extern void quit(environment *env)
724    else if((convert= sscanf(in_line, "%d %[^\n\r]", &itemp, rest)) >= 1)  {
725      push_val(stack_head, itemp);    int i;
   else if((convert= sscanf(in_line, "%[^ ;\n\r]%[^\n\r]", temp, rest)) >= 1)  
     push_ref(stack_head, in_hash, temp);  
   else if((convert= sscanf(in_line, "%c%[^\n\r]", temp, rest)) >= 1)  
     if(*temp==';')  
       eval(stack_head);  
726    
727    free(temp);    while(env->head->type != empty)
728        toss(env);
729    
730    if(convert<2) {    if (env->err) return;
731      free(rest);    for(i= 0; i<HASHTBLSIZE; i++) {
732      return 0;      while(env->symbols[i]!= NULL) {
733          forget_sym(&(env->symbols[i]));
734        }
735        env->symbols[i]= NULL;
736    }    }
737      
738    stack_read(stack_head, in_hash, rest);    env->gc_limit= 0;
739      gc_maybe(env);
740    
741      words(env);
742    
743      if(env->free_string!=NULL)
744        free(env->free_string);
745        
746    free(rest);  #ifdef __linux__
747    return 1;    muntrace();
748    #endif
749    
750      exit(EXIT_SUCCESS);
751  }  }
752    
753  extern void pack(stackitem** stack_head)  /* Internal forget function */
754    void forget_sym(symbol **hash_entry)
755  {  {
756    void* delimiter;    symbol *temp;
   stackitem *iterator, *temp, *pack;  
757    
758    if((*stack_head)==NULL)    temp= *hash_entry;
759      *hash_entry= (*hash_entry)->next;
760      
761      free(temp->id);
762      free(temp);
763    }
764    
765    /* Only to be called by itself function printstack. */
766    void print_st(environment *env, value *stack_head, long counter)
767    {
768      if(CDR(stack_head)->type != empty)
769        print_st(env, CDR(stack_head), counter+1);
770      printf("%ld: ", counter);
771      print_val(env, CAR(stack_head), 0, NULL, stdout);
772      printf("\n");
773    }
774    
775    /* Prints the stack. */
776    extern void printstack(environment *env)
777    {
778      if(env->head->type == empty) {
779        printf("Stack Empty\n");
780      return;      return;
781      }
782    
783      print_st(env, env->head, 1);
784    }
785    
786    int main(int argc, char **argv)
787    {
788      environment myenv;
789    
790      int c;                        /* getopt option character */
791    
792    delimiter= (*stack_head)->content.ptr;  #ifdef __linux__
793    toss(stack_head);    mtrace();
794    #endif
795    
796    iterator= *stack_head;    init_env(&myenv);
797    
798    while(iterator->next!=NULL && iterator->next->content.ptr!=delimiter)    myenv.interactive = isatty(STDIN_FILENO) && isatty(STDOUT_FILENO);
     iterator= iterator->next;  
799    
800    temp= *stack_head;    while ((c = getopt (argc, argv, "i")) != -1)
801    *stack_head= iterator->next;      switch (c)
802    iterator->next= NULL;        {
803          case 'i':
804            myenv.interactive = 1;
805            break;
806          case '?':
807            fprintf (stderr,
808                     "Unknown option character '\\x%x'.\n",
809                     optopt);
810            return EX_USAGE;
811          default:
812            abort ();
813          }
814        
815    if(*stack_head!=NULL && (*stack_head)->content.ptr==delimiter)    if (optind < argc) {
816      toss(stack_head);      myenv.interactive = 0;
817        myenv.inputstream= fopen(argv[optind], "r");
818        if(myenv.inputstream== NULL) {
819          perror(argv[0]);
820          exit (EX_NOINPUT);
821        }
822      }
823    
824    pack= malloc(sizeof(stackitem));    if(myenv.interactive) {
825    pack->type= list;      printf("Stack version $Revision$\n\
826    pack->content.ptr= temp;  Copyright (C) 2002  Mats Alritzson and Teddy Hogeborn\n\
827    Stack comes with ABSOLUTELY NO WARRANTY; for details type 'warranty;'.\n\
828    This is free software, and you are welcome to redistribute it\n\
829    under certain conditions; type 'copying;' for details.\n");
830      }
831    
832    push(stack_head, pack);    while(1) {
833        if(myenv.in_string==NULL) {
834          if (myenv.interactive) {
835            if(myenv.err) {
836              printf("(error %d)\n", myenv.err);
837              myenv.err= 0;
838            }
839            printf("\n");
840            printstack(&myenv);
841            printf("> ");
842          }
843          myenv.err=0;
844        }
845        readstream(&myenv, myenv.inputstream);
846        if (myenv.err) {            /* EOF or other error */
847          myenv.err=0;
848          quit(&myenv);
849        } else if(myenv.head->type!=empty
850                  && CAR(myenv.head)->type==symb
851                  && CAR(myenv.head)->content.sym->id[0] == ';') {
852          toss(&myenv); if(myenv.err) continue;
853          eval(&myenv);
854        } else {
855          gc_maybe(&myenv);
856        }
857      }
858      quit(&myenv);
859      return EXIT_FAILURE;
860  }  }
861    
862  extern void expand(stackitem** stack_head)  /* Return copy of a value */
863    value *copy_val(environment *env, value *old_value)
864  {  {
865    stackitem *temp, *new_head;    value *new_value;
866    
867    if((*stack_head)==NULL || (*stack_head)->type!=list)    if(old_value==NULL)
868      return;      return NULL;
869    
870    new_head= temp= (*stack_head)->content.ptr;    new_value= new_val(env);
871    toss(stack_head);    new_value->type= old_value->type;
872    
873    while(temp->next!=NULL)    switch(old_value->type){
874      temp= temp->next;    case tfloat:
875      case integer:
876      case func:
877      case symb:
878      case empty:
879      case port:
880        new_value->content= old_value->content;
881        break;
882      case string:
883        new_value->content.string= strdup(old_value->content.string);
884        break;
885      case tcons:
886    
887        new_value->content.c= malloc(sizeof(pair));
888        assert(new_value->content.c!=NULL);
889        env->gc_count += sizeof(pair);
890    
891        CAR(new_value)= copy_val(env, CAR(old_value)); /* recurse */
892        CDR(new_value)= copy_val(env, CDR(old_value)); /* recurse */
893        break;
894      }
895    
896    temp->next= *stack_head;    return new_value;
   *stack_head= new_head;  
897  }  }
898    
899  extern void quit()  /* read a line from a stream; used by readline */
900    void readlinestream(environment *env, FILE *stream)
901  {  {
902    exit(EXIT_SUCCESS);    char in_string[101];
903    
904      if(fgets(in_string, 100, stream)==NULL) {
905        push_cstring(env, "");
906        if (! feof(stream)){
907          perror("readline");
908          env->err= 5;
909        }
910      } else {
911        push_cstring(env, in_string);
912      }
913    }
914    
915    /* Reverse (flip) a list */
916    extern void rev(environment *env)
917    {
918      value *old_head, *new_head, *item;
919    
920      if(env->head->type==empty) {
921        printerr("Too Few Arguments");
922        env->err= 1;
923        return;
924      }
925    
926      if(CAR(env->head)->type==empty)
927        return;                     /* Don't reverse an empty list */
928    
929      if(CAR(env->head)->type!=tcons) {
930        printerr("Bad Argument Type");
931        env->err= 2;
932        return;
933      }
934    
935      old_head= CAR(env->head);
936      new_head= new_val(env);
937      while(old_head->type != empty) {
938        item= old_head;
939        old_head= CDR(old_head);
940        CDR(item)= new_head;
941        new_head= item;
942      }
943      CAR(env->head)= new_head;
944  }  }
945    
946  int main()  /* Make a list. */
947    extern void pack(environment *env)
948  {  {
949    stackitem* s= NULL;    value *iterator, *temp, *ending;
   hashtbl myhash;  
   char in_string[100];  
950    
951    init_hashtbl(myhash);    ending=new_val(env);
952    
953      iterator= env->head;
954      if(iterator->type == empty
955         || (CAR(iterator)->type==symb
956         && CAR(iterator)->content.sym->id[0]=='[')) {
957        temp= ending;
958        toss(env);
959      } else {
960        /* Search for first delimiter */
961        while(CDR(iterator)->type != empty
962              && (CAR(CDR(iterator))->type!=symb
963               || CAR(CDR(iterator))->content.sym->id[0]!='['))
964          iterator= CDR(iterator);
965        
966        /* Extract list */
967        temp= env->head;
968        env->head= CDR(iterator);
969        CDR(iterator)= ending;
970    
971    printf("okidok\n ");      if(env->head->type != empty)
972          toss(env);
973      }
974    
975      /* Push list */
976    
977    while(fgets(in_string, 100, stdin) != NULL) {    push_val(env, temp);
978      stack_read(&s, myhash, in_string);    rev(env);
979      printf("okidok\n ");  }
980    
981    /* read from a stream; used by "read" and "readport" */
982    void readstream(environment *env, FILE *stream)
983    {
984      const char symbform[]= "%[a-zA-Z0-9!$%*+./:<=>?@^_~-]%n";
985      const char strform[]= "\"%[^\"]\"%n";
986      const char intform[]= "%i%n";
987      const char fltform[]= "%f%n";
988      const char blankform[]= "%*[ \t]%n";
989      const char ebrackform[]= "]%n";
990      const char semicform[]= ";%n";
991      const char bbrackform[]= "[%n";
992    
993      int itemp, readlength= -1;
994      int count= -1;
995      float ftemp;
996      static int depth= 0;
997      char *match;
998      size_t inlength;
999    
1000      if(env->in_string==NULL) {
1001        if(depth > 0 && env->interactive) {
1002          printf("]> ");
1003        }
1004        readlinestream(env, env->inputstream);
1005        if(env->err) return;
1006    
1007        if((CAR(env->head)->content.string)[0]=='\0'){
1008          env->err= 4;              /* "" means EOF */
1009          return;
1010        }
1011        
1012        env->in_string= malloc(strlen(CAR(env->head)->content.string)+1);
1013        assert(env->in_string != NULL);
1014        env->free_string= env->in_string; /* Save the original pointer */
1015        strcpy(env->in_string, CAR(env->head)->content.string);
1016        toss(env); if(env->err) return;
1017      }
1018      
1019      inlength= strlen(env->in_string)+1;
1020      match= malloc(inlength);
1021      assert(match != NULL);
1022    
1023      if(sscanf(env->in_string, blankform, &readlength) != EOF
1024         && readlength != -1) {
1025        ;
1026      } else if(sscanf(env->in_string, fltform, &ftemp, &readlength) != EOF
1027                && readlength != -1) {
1028        if(sscanf(env->in_string, intform, &itemp, &count) != EOF
1029           && count==readlength) {
1030          push_int(env, itemp);
1031        } else {
1032          push_float(env, ftemp);
1033        }
1034      } else if(sscanf(env->in_string, "\"\"%n", &readlength) != EOF
1035                && readlength != -1) {
1036        push_cstring(env, "");
1037      } else if(sscanf(env->in_string, strform, match, &readlength) != EOF
1038                && readlength != -1) {
1039        push_cstring(env, match);
1040      } else if(sscanf(env->in_string, symbform, match, &readlength) != EOF
1041                && readlength != -1) {
1042        push_sym(env, match);
1043      } else if(sscanf(env->in_string, ebrackform, &readlength) != EOF
1044                && readlength != -1) {
1045        pack(env); if(env->err) return;
1046        if(depth != 0) depth--;
1047      } else if(sscanf(env->in_string, semicform, &readlength) != EOF
1048                && readlength != -1) {
1049        push_sym(env, ";");
1050      } else if(sscanf(env->in_string, bbrackform, &readlength) != EOF
1051                && readlength != -1) {
1052        push_sym(env, "[");
1053        depth++;
1054      } else {
1055        free(env->free_string);
1056        env->in_string = env->free_string = NULL;
1057    }    }
1058      if (env->in_string != NULL) {
1059        env->in_string += readlength;
1060      }
1061    
1062      free(match);
1063    
1064      if(depth)
1065        return readstream(env, env->inputstream);
1066    }
1067    
1068    return EXIT_SUCCESS;  extern void copying(environment *env)
1069    {
1070      printf("                  GNU GENERAL PUBLIC LICENSE\n\
1071                           Version 2, June 1991\n\
1072    \n\
1073     Copyright (C) 1989, 1991 Free Software Foundation, Inc.\n\
1074         59 Temple Place, Suite 330, Boston, MA  02111-1307  USA\n\
1075     Everyone is permitted to copy and distribute verbatim copies\n\
1076     of this license document, but changing it is not allowed.\n\
1077    \n\
1078                                Preamble\n\
1079    \n\
1080      The licenses for most software are designed to take away your\n\
1081    freedom to share and change it.  By contrast, the GNU General Public\n\
1082    License is intended to guarantee your freedom to share and change free\n\
1083    software--to make sure the software is free for all its users.  This\n\
1084    General Public License applies to most of the Free Software\n\
1085    Foundation's software and to any other program whose authors commit to\n\
1086    using it.  (Some other Free Software Foundation software is covered by\n\
1087    the GNU Library General Public License instead.)  You can apply it to\n\
1088    your programs, too.\n\
1089    \n\
1090      When we speak of free software, we are referring to freedom, not\n\
1091    price.  Our General Public Licenses are designed to make sure that you\n\
1092    have the freedom to distribute copies of free software (and charge for\n\
1093    this service if you wish), that you receive source code or can get it\n\
1094    if you want it, that you can change the software or use pieces of it\n\
1095    in new free programs; and that you know you can do these things.\n\
1096    \n\
1097      To protect your rights, we need to make restrictions that forbid\n\
1098    anyone to deny you these rights or to ask you to surrender the rights.\n\
1099    These restrictions translate to certain responsibilities for you if you\n\
1100    distribute copies of the software, or if you modify it.\n\
1101    \n\
1102      For example, if you distribute copies of such a program, whether\n\
1103    gratis or for a fee, you must give the recipients all the rights that\n\
1104    you have.  You must make sure that they, too, receive or can get the\n\
1105    source code.  And you must show them these terms so they know their\n\
1106    rights.\n\
1107    \n\
1108      We protect your rights with two steps: (1) copyright the software, and\n\
1109    (2) offer you this license which gives you legal permission to copy,\n\
1110    distribute and/or modify the software.\n\
1111    \n\
1112      Also, for each author's protection and ours, we want to make certain\n\
1113    that everyone understands that there is no warranty for this free\n\
1114    software.  If the software is modified by someone else and passed on, we\n\
1115    want its recipients to know that what they have is not the original, so\n\
1116    that any problems introduced by others will not reflect on the original\n\
1117    authors' reputations.\n\
1118    \n\
1119      Finally, any free program is threatened constantly by software\n\
1120    patents.  We wish to avoid the danger that redistributors of a free\n\
1121    program will individually obtain patent licenses, in effect making the\n\
1122    program proprietary.  To prevent this, we have made it clear that any\n\
1123    patent must be licensed for everyone's free use or not licensed at all.\n\
1124    \n\
1125      The precise terms and conditions for copying, distribution and\n\
1126    modification follow.\n\
1127    \n\
1128                        GNU GENERAL PUBLIC LICENSE\n\
1129       TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION\n\
1130    \n\
1131      0. This License applies to any program or other work which contains\n\
1132    a notice placed by the copyright holder saying it may be distributed\n\
1133    under the terms of this General Public License.  The \"Program\", below,\n\
1134    refers to any such program or work, and a \"work based on the Program\"\n\
1135    means either the Program or any derivative work under copyright law:\n\
1136    that is to say, a work containing the Program or a portion of it,\n\
1137    either verbatim or with modifications and/or translated into another\n\
1138    language.  (Hereinafter, translation is included without limitation in\n\
1139    the term \"modification\".)  Each licensee is addressed as \"you\".\n\
1140    \n\
1141    Activities other than copying, distribution and modification are not\n\
1142    covered by this License; they are outside its scope.  The act of\n\
1143    running the Program is not restricted, and the output from the Program\n\
1144    is covered only if its contents constitute a work based on the\n\
1145    Program (independent of having been made by running the Program).\n\
1146    Whether that is true depends on what the Program does.\n\
1147    \n\
1148      1. You may copy and distribute verbatim copies of the Program's\n\
1149    source code as you receive it, in any medium, provided that you\n\
1150    conspicuously and appropriately publish on each copy an appropriate\n\
1151    copyright notice and disclaimer of warranty; keep intact all the\n\
1152    notices that refer to this License and to the absence of any warranty;\n\
1153    and give any other recipients of the Program a copy of this License\n\
1154    along with the Program.\n\
1155    \n\
1156    You may charge a fee for the physical act of transferring a copy, and\n\
1157    you may at your option offer warranty protection in exchange for a fee.\n\
1158    \n\
1159      2. You may modify your copy or copies of the Program or any portion\n\
1160    of it, thus forming a work based on the Program, and copy and\n\
1161    distribute such modifications or work under the terms of Section 1\n\
1162    above, provided that you also meet all of these conditions:\n\
1163    \n\
1164        a) You must cause the modified files to carry prominent notices\n\
1165        stating that you changed the files and the date of any change.\n\
1166    \n\
1167        b) You must cause any work that you distribute or publish, that in\n\
1168        whole or in part contains or is derived from the Program or any\n\
1169        part thereof, to be licensed as a whole at no charge to all third\n\
1170        parties under the terms of this License.\n\
1171    \n\
1172        c) If the modified program normally reads commands interactively\n\
1173        when run, you must cause it, when started running for such\n\
1174        interactive use in the most ordinary way, to print or display an\n\
1175        announcement including an appropriate copyright notice and a\n\
1176        notice that there is no warranty (or else, saying that you provide\n\
1177        a warranty) and that users may redistribute the program under\n\
1178        these conditions, and telling the user how to view a copy of this\n\
1179        License.  (Exception: if the Program itself is interactive but\n\
1180        does not normally print such an announcement, your work based on\n\
1181        the Program is not required to print an announcement.)\n\
1182    \n\
1183    These requirements apply to the modified work as a whole.  If\n\
1184    identifiable sections of that work are not derived from the Program,\n\
1185    and can be reasonably considered independent and separate works in\n\
1186    themselves, then this License, and its terms, do not apply to those\n\
1187    sections when you distribute them as separate works.  But when you\n\
1188    distribute the same sections as part of a whole which is a work based\n\
1189    on the Program, the distribution of the whole must be on the terms of\n\
1190    this License, whose permissions for other licensees extend to the\n\
1191    entire whole, and thus to each and every part regardless of who wrote it.\n\
1192    \n\
1193    Thus, it is not the intent of this section to claim rights or contest\n\
1194    your rights to work written entirely by you; rather, the intent is to\n\
1195    exercise the right to control the distribution of derivative or\n\
1196    collective works based on the Program.\n\
1197    \n\
1198    In addition, mere aggregation of another work not based on the Program\n\
1199    with the Program (or with a work based on the Program) on a volume of\n\
1200    a storage or distribution medium does not bring the other work under\n\
1201    the scope of this License.\n\
1202    \n\
1203      3. You may copy and distribute the Program (or a work based on it,\n\
1204    under Section 2) in object code or executable form under the terms of\n\
1205    Sections 1 and 2 above provided that you also do one of the following:\n\
1206    \n\
1207        a) Accompany it with the complete corresponding machine-readable\n\
1208        source code, which must be distributed under the terms of Sections\n\
1209        1 and 2 above on a medium customarily used for software interchange; or,\n\
1210    \n\
1211        b) Accompany it with a written offer, valid for at least three\n\
1212        years, to give any third party, for a charge no more than your\n\
1213        cost of physically performing source distribution, a complete\n\
1214        machine-readable copy of the corresponding source code, to be\n\
1215        distributed under the terms of Sections 1 and 2 above on a medium\n\
1216        customarily used for software interchange; or,\n\
1217    \n\
1218        c) Accompany it with the information you received as to the offer\n\
1219        to distribute corresponding source code.  (This alternative is\n\
1220        allowed only for noncommercial distribution and only if you\n\
1221        received the program in object code or executable form with such\n\
1222        an offer, in accord with Subsection b above.)\n\
1223    \n\
1224    The source code for a work means the preferred form of the work for\n\
1225    making modifications to it.  For an executable work, complete source\n\
1226    code means all the source code for all modules it contains, plus any\n\
1227    associated interface definition files, plus the scripts used to\n\
1228    control compilation and installation of the executable.  However, as a\n\
1229    special exception, the source code distributed need not include\n\
1230    anything that is normally distributed (in either source or binary\n\
1231    form) with the major components (compiler, kernel, and so on) of the\n\
1232    operating system on which the executable runs, unless that component\n\
1233    itself accompanies the executable.\n\
1234    \n\
1235    If distribution of executable or object code is made by offering\n\
1236    access to copy from a designated place, then offering equivalent\n\
1237    access to copy the source code from the same place counts as\n\
1238    distribution of the source code, even though third parties are not\n\
1239    compelled to copy the source along with the object code.\n\
1240    \n\
1241      4. You may not copy, modify, sublicense, or distribute the Program\n\
1242    except as expressly provided under this License.  Any attempt\n\
1243    otherwise to copy, modify, sublicense or distribute the Program is\n\
1244    void, and will automatically terminate your rights under this License.\n\
1245    However, parties who have received copies, or rights, from you under\n\
1246    this License will not have their licenses terminated so long as such\n\
1247    parties remain in full compliance.\n\
1248    \n\
1249      5. You are not required to accept this License, since you have not\n\
1250    signed it.  However, nothing else grants you permission to modify or\n\
1251    distribute the Program or its derivative works.  These actions are\n\
1252    prohibited by law if you do not accept this License.  Therefore, by\n\
1253    modifying or distributing the Program (or any work based on the\n\
1254    Program), you indicate your acceptance of this License to do so, and\n\
1255    all its terms and conditions for copying, distributing or modifying\n\
1256    the Program or works based on it.\n\
1257    \n\
1258      6. Each time you redistribute the Program (or any work based on the\n\
1259    Program), the recipient automatically receives a license from the\n\
1260    original licensor to copy, distribute or modify the Program subject to\n\
1261    these terms and conditions.  You may not impose any further\n\
1262    restrictions on the recipients' exercise of the rights granted herein.\n\
1263    You are not responsible for enforcing compliance by third parties to\n\
1264    this License.\n\
1265    \n\
1266      7. If, as a consequence of a court judgment or allegation of patent\n\
1267    infringement or for any other reason (not limited to patent issues),\n\
1268    conditions are imposed on you (whether by court order, agreement or\n\
1269    otherwise) that contradict the conditions of this License, they do not\n\
1270    excuse you from the conditions of this License.  If you cannot\n\
1271    distribute so as to satisfy simultaneously your obligations under this\n\
1272    License and any other pertinent obligations, then as a consequence you\n\
1273    may not distribute the Program at all.  For example, if a patent\n\
1274    license would not permit royalty-free redistribution of the Program by\n\
1275    all those who receive copies directly or indirectly through you, then\n\
1276    the only way you could satisfy both it and this License would be to\n\
1277    refrain entirely from distribution of the Program.\n\
1278    \n\
1279    If any portion of this section is held invalid or unenforceable under\n\
1280    any particular circumstance, the balance of the section is intended to\n\
1281    apply and the section as a whole is intended to apply in other\n\
1282    circumstances.\n\
1283    \n\
1284    It is not the purpose of this section to induce you to infringe any\n\
1285    patents or other property right claims or to contest validity of any\n\
1286    such claims; this section has the sole purpose of protecting the\n\
1287    integrity of the free software distribution system, which is\n\
1288    implemented by public license practices.  Many people have made\n\
1289    generous contributions to the wide range of software distributed\n\
1290    through that system in reliance on consistent application of that\n\
1291    system; it is up to the author/donor to decide if he or she is willing\n\
1292    to distribute software through any other system and a licensee cannot\n\
1293    impose that choice.\n\
1294    \n\
1295    This section is intended to make thoroughly clear what is believed to\n\
1296    be a consequence of the rest of this License.\n\
1297    \n\
1298      8. If the distribution and/or use of the Program is restricted in\n\
1299    certain countries either by patents or by copyrighted interfaces, the\n\
1300    original copyright holder who places the Program under this License\n\
1301    may add an explicit geographical distribution limitation excluding\n\
1302    those countries, so that distribution is permitted only in or among\n\
1303    countries not thus excluded.  In such case, this License incorporates\n\
1304    the limitation as if written in the body of this License.\n\
1305    \n\
1306      9. The Free Software Foundation may publish revised and/or new versions\n\
1307    of the General Public License from time to time.  Such new versions will\n\
1308    be similar in spirit to the present version, but may differ in detail to\n\
1309    address new problems or concerns.\n\
1310    \n\
1311    Each version is given a distinguishing version number.  If the Program\n\
1312    specifies a version number of this License which applies to it and \"any\n\
1313    later version\", you have the option of following the terms and conditions\n\
1314    either of that version or of any later version published by the Free\n\
1315    Software Foundation.  If the Program does not specify a version number of\n\
1316    this License, you may choose any version ever published by the Free Software\n\
1317    Foundation.\n\
1318    \n\
1319      10. If you wish to incorporate parts of the Program into other free\n\
1320    programs whose distribution conditions are different, write to the author\n\
1321    to ask for permission.  For software which is copyrighted by the Free\n\
1322    Software Foundation, write to the Free Software Foundation; we sometimes\n\
1323    make exceptions for this.  Our decision will be guided by the two goals\n\
1324    of preserving the free status of all derivatives of our free software and\n\
1325    of promoting the sharing and reuse of software generally.\n");
1326    }
1327    
1328    extern void warranty(environment *env)
1329    {
1330      printf("                          NO WARRANTY\n\
1331    \n\
1332      11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY\n\
1333    FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN\n\
1334    OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES\n\
1335    PROVIDE THE PROGRAM \"AS IS\" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED\n\
1336    OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF\n\
1337    MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS\n\
1338    TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE\n\
1339    PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,\n\
1340    REPAIR OR CORRECTION.\n\
1341    \n\
1342      12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING\n\
1343    WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR\n\
1344    REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,\n\
1345    INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING\n\
1346    OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED\n\
1347    TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY\n\
1348    YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER\n\
1349    PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE\n\
1350    POSSIBILITY OF SUCH DAMAGES.\n");
1351    }
1352    
1353    /* Discard the top element of the stack. */
1354    extern void toss(environment *env)
1355    {
1356      if(env->head->type==empty) {
1357        printerr("Too Few Arguments");
1358        env->err= 1;
1359        return;
1360      }
1361      
1362      env->head= CDR(env->head); /* Remove the top stack item */
1363  }  }
1364    
 /* Local Variables: */  
 /* compile-command:"make CFLAGS=\"-Wall -g -rdynamic -ldl\" stack" */  
 /* End: */  
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