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revision 1.39 by teddy, Wed Feb 6 11:39:20 2002 UTC revision 1.105 by masse, Tue Mar 12 14:53:19 2002 UTC
# Line 1  Line 1 
1  /* printf */  /*
2        stack - an interactive interpreter for a stack-based language
3        Copyright (C) 2002  Mats Alritzson and Teddy Hogeborn
4    
5        This program is free software; you can redistribute it and/or modify
6        it under the terms of the GNU General Public License as published by
7        the Free Software Foundation; either version 2 of the License, or
8        (at your option) any later version.
9    
10        This program is distributed in the hope that it will be useful,
11        but WITHOUT ANY WARRANTY; without even the implied warranty of
12        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13        GNU General Public License for more details.
14    
15        You should have received a copy of the GNU General Public License
16        along with this program; if not, write to the Free Software
17        Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18    
19        Authors: Mats Alritzson <masse@fukt.bth.se>
20                 Teddy Hogeborn <teddy@fukt.bth.se>
21    */
22    
23    #define CAR(X) X->content.c->car
24    #define CDR(X) X->content.c->cdr
25    
26    /* printf, sscanf, fgets, fprintf, fopen, perror */
27  #include <stdio.h>  #include <stdio.h>
28  /* EXIT_SUCCESS */  /* exit, EXIT_SUCCESS, malloc, free */
29  #include <stdlib.h>  #include <stdlib.h>
30  /* NULL */  /* NULL */
31  #include <stddef.h>  #include <stddef.h>
32  /* dlopen, dlsym, dlerror */  /* dlopen, dlsym, dlerror */
33  #include <dlfcn.h>  #include <dlfcn.h>
34  /* assert */  /* strcmp, strcpy, strlen, strcat, strdup */
35  #include <assert.h>  #include <string.h>
36    /* getopt, STDIN_FILENO, STDOUT_FILENO, usleep */
37  #define HASHTBLSIZE 65536  #include <unistd.h>
38    /* EX_NOINPUT, EX_USAGE */
39    #include <sysexits.h>
40    /* mtrace, muntrace */
41    #include <mcheck.h>
42    /* ioctl */
43    #include <sys/ioctl.h>
44    /* KDMKTONE */
45    #include <linux/kd.h>
46    
47  /* First, define some types. */  #include "stack.h"
   
 /* A value of some type */  
 typedef struct {  
   enum {  
     integer,  
     string,  
     func,                       /* Function pointer */  
     symb,  
     list  
   } type;                       /* Type of stack element */  
   
   union {  
     void *ptr;                  /* Pointer to the content */  
     int val;                    /* ...or an integer */  
   } content;                    /* Stores a pointer or an integer */  
   
   int refcount;                 /* Reference counter */  
   
 } value;  
   
 /* A symbol with a name and possible value */  
 /* (These do not need reference counters, they are kept unique by  
    hashing.) */  
 typedef struct symbol_struct {  
   char *id;                     /* Symbol name */  
   value *val;                   /* The value (if any) bound to it */  
   struct symbol_struct *next;   /* In case of hashing conflicts, a */  
 } symbol;                       /* symbol is a kind of stack item. */  
   
 /* A type for a hash table for symbols */  
 typedef symbol *hashtbl[HASHTBLSIZE]; /* Hash table declaration */  
   
 /* An item (value) on a stack */  
 typedef struct stackitem_struct  
 {  
   value *item;                  /* The value on the stack */  
   struct stackitem_struct *next; /* Next item */  
 } stackitem;  
   
 /* An environment; gives access to the stack and a hash table of  
    defined symbols */  
 typedef struct {  
   stackitem *head;              /* Head of the stack */  
   hashtbl symbols;              /* Hash table of all variable bindings */  
   int err;                      /* Error flag */  
 } environment;  
   
 /* A type for pointers to external functions */  
 typedef void (*funcp)(environment *); /* funcp is a pointer to a void  
                                          function (environment *) */  
48    
49  /* Initialize a newly created environment */  /* Initialize a newly created environment */
50  void init_env(environment *env)  void init_env(environment *env)
51  {  {
52    long i;    int i;
53    
54      env->gc_limit= 400000;
55      env->gc_count= 0;
56      env->gc_ref= NULL;
57    
58    env->err=0;    env->head= NULL;
59    for(i= 0; i<HASHTBLSIZE; i++)    for(i= 0; i<HASHTBLSIZE; i++)
60      env->symbols[i]= NULL;      env->symbols[i]= NULL;
61      env->err= 0;
62      env->in_string= NULL;
63      env->free_string= NULL;
64      env->inputstream= stdin;
65      env->interactive= 1;
66    }
67    
68    void printerr(const char* in_string)
69    {
70      fprintf(stderr, "Err: %s\n", in_string);
71    }
72    
73    /* Discard the top element of the stack. */
74    extern void toss(environment *env)
75    {
76      if(env->head==NULL) {
77        printerr("Too Few Arguments");
78        env->err= 1;
79        return;
80      }
81      
82      env->head= CDR(env->head); /* Remove the top stack item */
83  }  }
84    
85  /* Returns a pointer to a pointer to an element in the hash table. */  /* Returns a pointer to a pointer to an element in the hash table. */
86  symbol **hash(hashtbl in_hashtbl, const char *in_string)  symbol **hash(hashtbl in_hashtbl, const char *in_string)
87  {  {
88    long i= 0;    int i= 0;
89    unsigned long out_hash= 0;    unsigned int out_hash= 0;
90    char key= '\0';    char key= '\0';
91    symbol **position;    symbol **position;
92        
# Line 102  symbol **hash(hashtbl in_hashtbl, const Line 111  symbol **hash(hashtbl in_hashtbl, const
111    }    }
112  }  }
113    
114  /* Generic push function. */  /* Create new value */
115  void push(stackitem** stack_head, stackitem* in_item)  value* new_val(environment *env)
116    {
117      value *nval= malloc(sizeof(value));
118      stackitem *nitem= malloc(sizeof(stackitem));
119    
120      nval->content.ptr= NULL;
121    
122      nitem->item= nval;
123      nitem->next= env->gc_ref;
124    
125      env->gc_ref= nitem;
126    
127      env->gc_count += sizeof(value);
128      nval->gc.flag.mark= 0;
129      nval->gc.flag.protect= 0;
130    
131      return nval;
132    }
133    
134    /* Mark values recursively.
135       Marked values are not collected by the GC. */
136    inline void gc_mark(value *val)
137    {
138      if(val==NULL || val->gc.flag.mark)
139        return;
140    
141      val->gc.flag.mark= 1;
142    
143      if(val->type==tcons) {
144        gc_mark(CAR(val));
145        gc_mark(CDR(val));
146      }
147    }
148    
149    inline void gc_maybe(environment *env)
150    {
151      if(env->gc_count < env->gc_limit)
152        return;
153      else
154        return gc_init(env);
155    }
156    
157    /* Start GC */
158    extern void gc_init(environment *env)
159    {
160      stackitem *new_head= NULL, *titem;
161      cons *iterator;
162      symbol *tsymb;
163      int i;
164    
165      if(env->interactive)
166        printf("Garbage collecting.");
167    
168      /* Mark values on stack */
169      gc_mark(env->head);
170    
171      if(env->interactive)
172        printf(".");
173    
174    
175      /* Mark values in hashtable */
176      for(i= 0; i<HASHTBLSIZE; i++)
177        for(tsymb= env->symbols[i]; tsymb!=NULL; tsymb= tsymb->next)
178          if (tsymb->val != NULL)
179            gc_mark(tsymb->val);
180    
181    
182      if(env->interactive)
183        printf(".");
184    
185    
186      env->gc_count= 0;
187    
188      while(env->gc_ref!=NULL) {    /* Sweep unused values */
189    
190        if(!(env->gc_ref->item->gc.no_gc)){ /* neither mark nor protect */
191    
192          if(env->gc_ref->item->type==string) /* Remove content */
193            free(env->gc_ref->item->content.ptr);
194    
195          free(env->gc_ref->item);  /* Remove from gc_ref */
196          titem= env->gc_ref->next;
197          free(env->gc_ref);        /* Remove value */
198          env->gc_ref= titem;
199          continue;
200        }
201    
202        /* Keep values */    
203        env->gc_count += sizeof(value);
204        if(env->gc_ref->item->type==string)
205          env->gc_count += strlen(env->gc_ref->item->content.ptr);
206        
207        titem= env->gc_ref->next;
208        env->gc_ref->next= new_head;
209        new_head= env->gc_ref;
210        new_head->item->gc.flag.mark= 0;
211        env->gc_ref= titem;
212      }
213    
214      if (env->gc_limit < env->gc_count*2)
215        env->gc_limit= env->gc_count*2;
216    
217      env->gc_ref= new_head;
218    
219      if(env->interactive)
220        printf("done\n");
221    
222    }
223    
224    /* Protect values from GC */
225    void protect(value *val)
226  {  {
227    in_item->next= *stack_head;    if(val==NULL || val->gc.flag.protect)
228    *stack_head= in_item;      return;
229    
230      val->gc.flag.protect= 1;
231    
232      if(val->type==tcons) {
233        protect(CAR(val));
234        protect(CDR(val));
235      }
236    }
237    
238    /* Unprotect values from GC */
239    void unprotect(value *val)
240    {
241      if(val==NULL || !(val->gc.flag.protect))
242        return;
243    
244      val->gc.flag.protect= 0;
245    
246      if(val->type==tcons) {
247        unprotect(CAR(val));
248        unprotect(CDR(val));
249      }
250  }  }
251    
252  /* Push a value onto the stack */  /* Push a value onto the stack */
253  void push_val(stackitem **stack_head, value *val)  void push_val(environment *env, value *val)
254  {  {
255    stackitem *new_item= malloc(sizeof(stackitem));    value *new_value= new_val(env);
256    new_item->item= val;  
257    val->refcount++;    new_value->content.c= malloc(sizeof(cons));
258    push(stack_head, new_item);    new_value->type= tcons;
259      CAR(new_value)= val;
260      CDR(new_value)= env->head;
261      env->head= new_value;
262  }  }
263    
264  /* Push an integer onto the stack. */  /* Push an integer onto the stack */
265  void push_int(stackitem **stack_head, int in_val)  void push_int(environment *env, int in_val)
266  {  {
267    value *new_value= malloc(sizeof(value));    value *new_value= new_val(env);
   stackitem *new_item= malloc(sizeof(stackitem));  
   new_item->item= new_value;  
268        
269    new_value->content.val= in_val;    new_value->content.i= in_val;
270    new_value->type= integer;    new_value->type= integer;
   new_value->refcount=1;  
271    
272    push(stack_head, new_item);    push_val(env, new_value);
273    }
274    
275    /* Push a floating point number onto the stack */
276    void push_float(environment *env, float in_val)
277    {
278      value *new_value= new_val(env);
279    
280      new_value->content.f= in_val;
281      new_value->type= tfloat;
282    
283      push_val(env, new_value);
284  }  }
285    
286  /* Copy a string onto the stack. */  /* Copy a string onto the stack. */
287  void push_cstring(stackitem **stack_head, const char *in_string)  void push_cstring(environment *env, const char *in_string)
288  {  {
289    value *new_value= malloc(sizeof(value));    value *new_value= new_val(env);
290    stackitem *new_item= malloc(sizeof(stackitem));    int length= strlen(in_string)+1;
   new_item->item=new_value;  
291    
292    new_value->content.ptr= malloc(strlen(in_string)+1);    new_value->content.ptr= malloc(length);
293      env->gc_count += length;
294    strcpy(new_value->content.ptr, in_string);    strcpy(new_value->content.ptr, in_string);
295    new_value->type= string;    new_value->type= string;
   new_value->refcount=1;  
296    
297    push(stack_head, new_item);    push_val(env, new_value);
298    }
299    
300    /* Mangle a symbol name to a valid C identifier name */
301    char *mangle_str(const char *old_string)
302    {
303      char validchars[]= "0123456789abcdef";
304      char *new_string, *current;
305    
306      new_string= malloc((strlen(old_string)*2)+4);
307      strcpy(new_string, "sx_");    /* Stack eXternal */
308      current= new_string+3;
309      while(old_string[0] != '\0'){
310        current[0]= validchars[(unsigned char)(old_string[0])/16];
311        current[1]= validchars[(unsigned char)(old_string[0])%16];
312        current+= 2;
313        old_string++;
314      }
315      current[0]= '\0';
316    
317      return new_string;            /* The caller must free() it */
318    }
319    
320    extern void mangle(environment *env)
321    {
322      char *new_string;
323    
324      if(env->head==NULL) {
325        printerr("Too Few Arguments");
326        env->err= 1;
327        return;
328      }
329    
330      if(CAR(env->head)->type!=string) {
331        printerr("Bad Argument Type");
332        env->err= 2;
333        return;
334      }
335    
336      new_string=
337        mangle_str((const char *)(CAR(env->head)->content.ptr));
338    
339      toss(env);
340      if(env->err) return;
341    
342      push_cstring(env, new_string);
343  }  }
344    
345  /* Push a symbol onto the stack. */  /* Push a symbol onto the stack. */
346  void push_sym(environment *env, const char *in_string)  void push_sym(environment *env, const char *in_string)
347  {  {
   stackitem *new_item;          /* The new stack item */  
   /* ...which will contain... */  
348    value *new_value;             /* A new symbol value */    value *new_value;             /* A new symbol value */
349    /* ...which might point to... */    /* ...which might point to... */
350    symbol **new_symbol;          /* (if needed) A new actual symbol */    symbol **new_symbol;          /* (if needed) A new actual symbol */
# Line 161  void push_sym(environment *env, const ch Line 354  void push_sym(environment *env, const ch
354    void *funcptr;                /* A function pointer */    void *funcptr;                /* A function pointer */
355    
356    static void *handle= NULL;    /* Dynamic linker handle */    static void *handle= NULL;    /* Dynamic linker handle */
357      const char *dlerr;            /* Dynamic linker error */
358      char *mangled;                /* Mangled function name */
359    
360    /* Create a new stack item containing a new value */    new_value= new_val(env);
361    new_item= malloc(sizeof(stackitem));    protect(new_value);
362    new_value= malloc(sizeof(value));    new_fvalue= new_val(env);
363    new_item->item=new_value;    protect(new_fvalue);
364    
365    /* The new value is a symbol */    /* The new value is a symbol */
366    new_value->type= symb;    new_value->type= symb;
   new_value->refcount= 1;  
367    
368    /* Look up the symbol name in the hash table */    /* Look up the symbol name in the hash table */
369    new_symbol= hash(env->symbols, in_string);    new_symbol= hash(env->symbols, in_string);
# Line 192  void push_sym(environment *env, const ch Line 386  void push_sym(environment *env, const ch
386      if(handle==NULL)            /* If no handle */      if(handle==NULL)            /* If no handle */
387        handle= dlopen(NULL, RTLD_LAZY);        handle= dlopen(NULL, RTLD_LAZY);
388    
389      funcptr= dlsym(handle, in_string); /* Get function pointer */      mangled= mangle_str(in_string); /* mangle the name */
390      if(dlerror()==NULL) {       /* If a function was found */      funcptr= dlsym(handle, mangled); /* and try to find it */
391        new_fvalue= malloc(sizeof(value)); /* Create a new value */  
392        new_fvalue->type=func;    /* The new value is a function pointer */      dlerr= dlerror();
393        new_fvalue->content.ptr=funcptr; /* Store function pointer */      if(dlerr != NULL) {         /* If no function was found */
394          funcptr= dlsym(handle, in_string); /* Get function pointer */
395          dlerr= dlerror();
396        }
397    
398        if(dlerr==NULL) {           /* If a function was found */
399          new_fvalue->type= func;   /* The new value is a function pointer */
400          new_fvalue->content.ptr= funcptr; /* Store function pointer */
401        (*new_symbol)->val= new_fvalue; /* Bind the symbol to the new        (*new_symbol)->val= new_fvalue; /* Bind the symbol to the new
402                                           function value */                                           function value */
       new_fvalue->refcount= 1;  
403      }      }
   }  
   push(&(env->head), new_item);  
 }  
   
 void printerr(const char* in_string) {  
   fprintf(stderr, "Err: %s\n", in_string);  
 }  
404    
405  /* Throw away a value */      free(mangled);
 void free_val(value *val){  
   stackitem *item, *temp;  
   
   val->refcount--;              /* Decrease the reference count */  
   if(val->refcount == 0){  
     switch (val->type){         /* and free the contents if necessary */  
     case string:  
       free(val->content.ptr);  
       break;  
     case list:                  /* lists needs to be freed recursively */  
       item=val->content.ptr;  
       while(item != NULL) {     /* for all stack items */  
         free_val(item->item);   /* free the value */  
         temp=item->next;        /* save next ptr */  
         free(item);             /* free the stackitem */  
         item=temp;              /* go to next stackitem */  
       }  
       free(val);                /* Free the actual list value */  
       break;  
     default:  
       break;  
     }  
406    }    }
 }  
407    
408  /* Discard the top element of the stack. */    push_val(env, new_value);
409  extern void toss(environment *env)    unprotect(new_value); unprotect(new_fvalue);
 {  
   stackitem *temp= env->head;  
   
   if((env->head)==NULL) {  
     printerr("Too Few Arguments");  
     env->err=1;  
     return;  
   }  
     
   free_val(env->head->item);    /* Free the value */  
   env->head= env->head->next;   /* Remove the top stack item */  
   free(temp);                   /* Free the old top stack item */  
410  }  }
411    
412  /* Print newline. */  /* Print newline. */
# Line 258  extern void nl() Line 416  extern void nl()
416  }  }
417    
418  /* Gets the type of a value */  /* Gets the type of a value */
419  extern void type(environment *env){  extern void type(environment *env)
420    {
421    int typenum;    int typenum;
422    
423    if((env->head)==NULL) {    if(env->head==NULL) {
424      printerr("Too Few Arguments");      printerr("Too Few Arguments");
425      env->err=1;      env->err= 1;
426      return;      return;
427    }    }
428    typenum=env->head->item->type;  
429      typenum= CAR(env->head)->type;
430    toss(env);    toss(env);
431    switch(typenum){    switch(typenum){
432    case integer:    case integer:
433      push_sym(env, "integer");      push_sym(env, "integer");
434      break;      break;
435      case tfloat:
436        push_sym(env, "float");
437        break;
438    case string:    case string:
439      push_sym(env, "string");      push_sym(env, "string");
440      break;      break;
# Line 281  extern void type(environment *env){ Line 444  extern void type(environment *env){
444    case func:    case func:
445      push_sym(env, "function");      push_sym(env, "function");
446      break;      break;
447    case list:    case tcons:
448      push_sym(env, "list");      push_sym(env, "list");
449      break;      break;
   default:  
     push_sym(env, "unknown");  
     break;  
450    }    }
451  }      }    
452    
453  /* Prints the top element of the stack. */  /* Prints the top element of the stack. */
454  void print_h(stackitem *stack_head)  void print_h(value *stack_head, int noquote)
455  {  {
456    switch(stack_head->item->type) {    switch(CAR(stack_head)->type) {
457    case integer:    case integer:
458      printf("%d", stack_head->item->content.val);      printf("%d", CAR(stack_head)->content.i);
459        break;
460      case tfloat:
461        printf("%f", CAR(stack_head)->content.f);
462      break;      break;
463    case string:    case string:
464      printf("\"%s\"", (char*)stack_head->item->content.ptr);      if(noquote)
465          printf("%s", (char*)CAR(stack_head)->content.ptr);
466        else
467          printf("\"%s\"", (char*)CAR(stack_head)->content.ptr);
468      break;      break;
469    case symb:    case symb:
470      printf("'%s'", ((symbol *)(stack_head->item->content.ptr))->id);      printf("%s", CAR(stack_head)->content.sym->id);
471      break;      break;
472    case func:    case func:
473      printf("#<function %p>", (funcp)(stack_head->item->content.ptr));      printf("#<function %p>", (funcp)(CAR(stack_head)->content.ptr));
474      break;      break;
475    case list:    case tcons:
476      /* A list is just a stack, so make stack_head point to it */      /* A list is just a stack, so make stack_head point to it */
477      stack_head=(stackitem *)(stack_head->item->content.ptr);      stack_head= CAR(stack_head);
478      printf("[ ");      printf("[ ");
479      while(stack_head != NULL) {      while(stack_head != NULL) {
480        print_h(stack_head);        print_h(stack_head, noquote);
481        printf(" ");        printf(" ");
482        stack_head=stack_head->next;        stack_head= CDR(stack_head);
483      }      }
484      printf("]");      printf("]");
485      break;      break;
   default:  
     printf("#<unknown %p>", (stack_head->item->content.ptr));  
     break;  
486    }    }
487  }  }
488    
489  extern void print_(environment *env) {  extern void print_(environment *env)
490    {
491    if(env->head==NULL) {    if(env->head==NULL) {
492      printerr("Too Few Arguments");      printerr("Too Few Arguments");
493      env->err=1;      env->err= 1;
494      return;      return;
495    }    }
496    print_h(env->head);    print_h(env->head, 0);
497      nl();
498  }  }
499    
500  /* Prints the top element of the stack and then discards it. */  /* Prints the top element of the stack and then discards it. */
# Line 340  extern void print(environment *env) Line 505  extern void print(environment *env)
505    toss(env);    toss(env);
506  }  }
507    
508    extern void princ_(environment *env)
509    {
510      if(env->head==NULL) {
511        printerr("Too Few Arguments");
512        env->err= 1;
513        return;
514      }
515      print_h(env->head, 1);
516    }
517    
518    /* Prints the top element of the stack and then discards it. */
519    extern void princ(environment *env)
520    {
521      princ_(env);
522      if(env->err) return;
523      toss(env);
524    }
525    
526  /* Only to be called by function printstack. */  /* Only to be called by function printstack. */
527  void print_st(stackitem *stack_head, long counter)  void print_st(value *stack_head, long counter)
528  {  {
529    if(stack_head->next != NULL)    if(CDR(stack_head) != NULL)
530      print_st(stack_head->next, counter+1);      print_st(CDR(stack_head), counter+1);
531    printf("%ld: ", counter);    printf("%ld: ", counter);
532    print_h(stack_head);    print_h(stack_head, 0);
533    nl();    nl();
534  }  }
535    
   
   
536  /* Prints the stack. */  /* Prints the stack. */
537  extern void printstack(environment *env)  extern void printstack(environment *env)
538  {  {
539    if(env->head == NULL) {    if(env->head == NULL) {
540        printf("Stack Empty\n");
541      return;      return;
542    }    }
543    
544    print_st(env->head, 1);    print_st(env->head, 1);
   nl();  
545  }  }
546    
547  /* Swap the two top elements on the stack. */  /* Swap the two top elements on the stack. */
548  extern void swap(environment *env)  extern void swap(environment *env)
549  {  {
550    stackitem *temp= env->head;    value *temp= env->head;
551        
552    if((env->head)==NULL) {    if(env->head==NULL || CDR(env->head)==NULL) {
553      printerr("Too Few Arguments");      printerr("Too Few Arguments");
554      env->err=1;      env->err=1;
555      return;      return;
556    }    }
557    
558    if(env->head->next==NULL) {    env->head= CDR(env->head);
559      printerr("Too Few Arguments");    CDR(temp)= CDR(env->head);
560      env->err=1;    CDR(env->head)= temp;
     return;  
   }  
   
   env->head= env->head->next;  
   temp->next= env->head->next;  
   env->head->next= temp;  
561  }  }
562    
563  stackitem* copy(stackitem* in_item)  /* Rotate the first three elements on the stack. */
564    extern void rot(environment *env)
565  {  {
566    stackitem *out_item= malloc(sizeof(stackitem));    value *temp= env->head;
567      
568    memcpy(out_item, in_item, sizeof(stackitem));    if(env->head==NULL || CDR(env->head)==NULL
569    out_item->next= NULL;       || CDR(CDR(env->head))==NULL) {
570        printerr("Too Few Arguments");
571    return out_item;      env->err= 1;
572        return;
573      }
574      
575      env->head= CDR(CDR(env->head));
576      CDR(CDR(temp))= CDR(env->head);
577      CDR(env->head)= temp;
578  }  }
579    
580  /* Recall a value from a symbol, if bound */  /* Recall a value from a symbol, if bound */
# Line 399  extern void rcl(environment *env) Line 582  extern void rcl(environment *env)
582  {  {
583    value *val;    value *val;
584    
585    if(env->head == NULL) {    if(env->head==NULL) {
586      printerr("Too Few Arguments");      printerr("Too Few Arguments");
587      env->err=1;      env->err= 1;
588      return;      return;
589    }    }
590    
591    if(env->head->item->type!=symb) {    if(CAR(env->head)->type!=symb) {
592      printerr("Bad Argument Type");      printerr("Bad Argument Type");
593      env->err=2;      env->err= 2;
594      return;      return;
595    }    }
596    
597    val=((symbol *)(env->head->item->content.ptr))->val;    val= CAR(env->head)->content.sym->val;
598    if(val == NULL){    if(val == NULL){
599      printerr("Unbound Variable");      printerr("Unbound Variable");
600      env->err=3;      env->err= 3;
601      return;      return;
602    }    }
603      protect(val);
604    toss(env);            /* toss the symbol */    toss(env);            /* toss the symbol */
605    if(env->err) return;    if(env->err) return;
606    push_val(&(env->head), val); /* Return its bound value */    push_val(env, val); /* Return its bound value */
607      unprotect(val);
608  }  }
609    
610  /* If the top element is a symbol, determine if it's bound to a  /* If the top element is a symbol, determine if it's bound to a
# Line 428  extern void rcl(environment *env) Line 613  extern void rcl(environment *env)
613  extern void eval(environment *env)  extern void eval(environment *env)
614  {  {
615    funcp in_func;    funcp in_func;
616      value* temp_val;
617      value* iterator;
618    
619     eval_start:
620    
621      gc_maybe(env);
622    
623    if(env->head==NULL) {    if(env->head==NULL) {
624      printerr("Too Few Arguments");      printerr("Too Few Arguments");
625      env->err=1;      env->err= 1;
626      return;      return;
627    }    }
628    
629    /* if it's a symbol */    switch(CAR(env->head)->type) {
630    if(env->head->item->type==symb) {      /* if it's a symbol */
631      case symb:
632      rcl(env);                   /* get its contents */      rcl(env);                   /* get its contents */
633      if(env->err) return;      if(env->err) return;
634      if(env->head->item->type!=symb){ /* don't recurse symbols */      if(CAR(env->head)->type!=symb){ /* don't recurse symbols */
635        eval(env);                        /* evaluate the value */        goto eval_start;
       return;  
636      }      }
637    }      return;
638    
639    /* If it's a lone function value, run it */      /* If it's a lone function value, run it */
640    if(env->head->item->type==func) {    case func:
641      in_func= (funcp)(env->head->item->content.ptr);      in_func= (funcp)(CAR(env->head)->content.ptr);
642      toss(env);      toss(env);
643      if(env->err) return;      if(env->err) return;
644      (*in_func)(env);      return in_func(env);
645    
646        /* If it's a list */
647      case tcons:
648        temp_val= CAR(env->head);
649        protect(temp_val);
650    
651        toss(env); if(env->err) return;
652        iterator= temp_val;
653        
654        while(iterator!=NULL) {
655          push_val(env, CAR(iterator));
656          
657          if(CAR(env->head)->type==symb
658             && CAR(env->head)->content.sym->id[0]==';') {
659            toss(env);
660            if(env->err) return;
661            
662            if(CDR(iterator)==NULL){
663              goto eval_start;
664            }
665            eval(env);
666            if(env->err) return;
667          }
668          if (CDR(iterator)->type == tcons)
669            iterator= CDR(iterator);
670          else {
671            printerr("Bad Argument Type"); /* Improper list */
672            env->err= 2;
673            return;
674          }
675        }
676        unprotect(temp_val);
677        return;
678    
679      default:
680        return;
681    }    }
682  }  }
683    
684    /* Reverse (flip) a list */
685    extern void rev(environment *env)
686    {
687      value *old_head, *new_head, *item;
688    
689      if(env->head==NULL) {
690        printerr("Too Few Arguments");
691        env->err= 1;
692        return;
693      }
694    
695      if(CAR(env->head)->type!=tcons) {
696        printerr("Bad Argument Type");
697        env->err= 2;
698        return;
699      }
700    
701      old_head= CAR(env->head);
702      new_head= NULL;
703      while(old_head!=NULL) {
704        item= old_head;
705        old_head= CDR(old_head);
706        CDR(item)= new_head;
707        new_head= item;
708      }
709      CAR(env->head)= new_head;
710    }
711    
712  /* Make a list. */  /* Make a list. */
713  extern void pack(environment *env)  extern void pack(environment *env)
714  {  {
715    void* delimiter;    value *iterator, *temp;
   stackitem *iterator, *temp;  
   value *pack;  
   
   delimiter= env->head->item->content.ptr; /* Get delimiter */  
   toss(env);  
716    
717    iterator= env->head;    iterator= env->head;
718      if(iterator==NULL
719    if(iterator==NULL || iterator->item->content.ptr==delimiter) {       || (CAR(iterator)->type==symb
720         && CAR(iterator)->content.sym->id[0]=='[')) {
721      temp= NULL;      temp= NULL;
722      toss(env);      toss(env);
723    } else {    } else {
724      /* Search for first delimiter */      /* Search for first delimiter */
725      while(iterator->next!=NULL      while(CDR(iterator)!=NULL
726            && iterator->next->item->content.ptr!=delimiter)            && (CAR(CDR(iterator))->type!=symb
727        iterator= iterator->next;             || CAR(CDR(iterator))->content.sym->id[0]!='['))
728          iterator= CDR(iterator);
729            
730      /* Extract list */      /* Extract list */
731      temp= env->head;      temp= env->head;
732      env->head= iterator->next;      env->head= CDR(iterator);
733      iterator->next= NULL;      CDR(iterator)= NULL;
734        
735      if(env->head!=NULL)      if(env->head!=NULL)
736        toss(env);        toss(env);
737    }    }
738    
739    /* Push list */    /* Push list */
   pack= malloc(sizeof(value));  
   pack->type= list;  
   pack->content.ptr= temp;  
   pack->refcount= 1;  
   
   temp= malloc(sizeof(stackitem));  
   temp->item= pack;  
740    
741    push(&(env->head), temp);    push_val(env, temp);
742  }    rev(env);
   
 /* Parse input. */  
 void stack_read(environment *env, char *in_line)  
 {  
   char *temp, *rest;  
   int itemp;  
   size_t inlength= strlen(in_line)+1;  
   int convert= 0;  
   static int non_eval_flag= 0;  
   
   temp= malloc(inlength);  
   rest= malloc(inlength);  
   
   do {  
     /* If string */  
     if((convert= sscanf(in_line, "\"%[^\"\n\r]\" %[^\n\r]", temp, rest))) {  
       push_cstring(&(env->head), temp);  
       break;  
     }  
     /* If integer */  
     if((convert= sscanf(in_line, "%d %[^\n\r]", &itemp, rest))) {  
       push_int(&(env->head), itemp);  
       break;  
     }  
     /* Escape ';' with '\' */  
     if((convert= sscanf(in_line, "\\%c%[^\n\r]", temp, rest))) {  
       temp[1]= '\0';  
       push_sym(env, temp);  
       break;  
     }  
     /* If symbol */  
     if((convert= sscanf(in_line, "%[^][ ;\n\r]%[^\n\r]", temp, rest))) {  
         push_sym(env, temp);  
         break;  
     }  
     /* If single char */  
     if((convert= sscanf(in_line, "%c%[^\n\r]", temp, rest))) {  
       if(*temp==';') {  
         if(!non_eval_flag) {  
           eval(env);            /* Evaluate top element */  
           break;  
         }  
           
         push_sym(env, ";");  
         break;  
       }  
   
       if(*temp==']') {  
         push_sym(env, "[");  
         pack(env);  
         if(non_eval_flag!=0)  
           non_eval_flag--;  
         break;  
       }  
   
       if(*temp=='[') {  
         push_sym(env, "[");  
         non_eval_flag++;  
         break;  
       }  
     }  
   } while(0);  
   
   free(temp);  
   
   if(convert<2) {  
     free(rest);  
     return;  
   }  
     
   stack_read(env, rest);  
     
   free(rest);  
743  }  }
744    
745  /* Relocate elements of the list on the stack. */  /* Relocate elements of the list on the stack. */
746  extern void expand(environment *env)  extern void expand(environment *env)
747  {  {
748    stackitem *temp, *new_head;    value *temp, *new_head;
749    
750    /* Is top element a list? */    /* Is top element a list? */
751    if(env->head==NULL) {    if(env->head==NULL) {
752      printerr("Too Few Arguments");      printerr("Too Few Arguments");
753      env->err=1;      env->err= 1;
754      return;      return;
755    }    }
756    if(env->head->item->type!=list) {  
757      if(CAR(env->head)->type!=tcons) {
758      printerr("Bad Argument Type");      printerr("Bad Argument Type");
759      env->err=2;      env->err= 2;
760      return;      return;
761    }    }
762    
763      rev(env);
764    
765      if(env->err)
766        return;
767    
768    /* The first list element is the new stack head */    /* The first list element is the new stack head */
769    new_head= temp= env->head->item->content.ptr;    new_head= temp= CAR(env->head);
770    
   env->head->item->refcount++;  
771    toss(env);    toss(env);
772    
773    /* Find the end of the list */    /* Find the end of the list */
774    while(temp->next!=NULL)    while(CDR(temp)->content.ptr != NULL) {
775      temp= temp->next;      if (CDR(temp)->type == tcons)
776          temp= CDR(temp);
777        else {
778          printerr("Bad Argument Type"); /* Improper list */
779          env->err= 2;
780          return;
781        }
782      }
783    
784    /* Connect the tail of the list with the old stack head */    /* Connect the tail of the list with the old stack head */
785    temp->next= env->head;    CDR(temp)= env->head;
786    env->head= new_head;          /* ...and voila! */    env->head= new_head;          /* ...and voila! */
787    
788  }  }
789    
 /* Reverse a list */  
 extern void rev(environment *env){  
   stackitem *old_head, *new_head, *item;  
   
   if((env->head)==NULL) {  
     printerr("Too Few Arguments");  
     env->err=1;  
     return;  
   }  
   
   if(env->head->item->type!=list) {  
     printerr("Bad Argument Type");  
     env->err=2;  
     return;  
   }  
   
   old_head=(stackitem *)(env->head->item->content.ptr);  
   new_head=NULL;  
   while(old_head != NULL){  
     item=old_head;  
     old_head=old_head->next;  
     item->next=new_head;  
     new_head=item;  
   }  
   env->head->item->content.ptr=new_head;  
 }  
   
790  /* Compares two elements by reference. */  /* Compares two elements by reference. */
791  extern void eq(environment *env)  extern void eq(environment *env)
792  {  {
793    void *left, *right;    void *left, *right;
   int result;  
794    
795    if((env->head)==NULL || env->head->next==NULL) {    if(env->head==NULL || CDR(env->head)==NULL) {
796      printerr("Too Few Arguments");      printerr("Too Few Arguments");
797      env->err=1;      env->err= 1;
798      return;      return;
799    }    }
800    
801    left= env->head->item->content.ptr;    left= CAR(env->head)->content.ptr;
802    swap(env);    right= CAR(CDR(env->head))->content.ptr;
   right= env->head->item->content.ptr;  
   result= (left==right);  
     
803    toss(env); toss(env);    toss(env); toss(env);
804    push_int(&(env->head), result);  
805      push_int(env, left==right);
806  }  }
807    
808  /* Negates the top element on the stack. */  /* Negates the top element on the stack. */
# Line 656  extern void not(environment *env) Line 810  extern void not(environment *env)
810  {  {
811    int val;    int val;
812    
813    if((env->head)==NULL) {    if(env->head==NULL) {
814      printerr("Too Few Arguments");      printerr("Too Few Arguments");
815      env->err=1;      env->err= 1;
816      return;      return;
817    }    }
818    
819    if(env->head->item->type!=integer) {    if(CAR(env->head)->type!=integer) {
820      printerr("Bad Argument Type");      printerr("Bad Argument Type");
821      env->err=2;      env->err= 2;
822      return;      return;
823    }    }
824    
825    val= env->head->item->content.val;    val= CAR(env->head)->content.i;
826    toss(env);    toss(env);
827    push_int(&(env->head), !val);    push_int(env, !val);
828  }  }
829    
830  /* Compares the two top elements on the stack and return 0 if they're the  /* Compares the two top elements on the stack and return 0 if they're the
# Line 687  extern void def(environment *env) Line 841  extern void def(environment *env)
841    symbol *sym;    symbol *sym;
842    
843    /* Needs two values on the stack, the top one must be a symbol */    /* Needs two values on the stack, the top one must be a symbol */
844    if(env->head==NULL || env->head->next==NULL) {    if(env->head==NULL || CDR(env->head)==NULL) {
845      printerr("Too Few Arguments");      printerr("Too Few Arguments");
846      env->err=1;      env->err= 1;
847      return;      return;
848    }    }
849    
850    if(env->head->item->type!=symb) {    if(CAR(env->head)->type!=symb) {
851      printerr("Bad Argument Type");      printerr("Bad Argument Type");
852      env->err=2;      env->err= 2;
853      return;      return;
854    }    }
855    
856    /* long names are a pain */    /* long names are a pain */
857    sym=env->head->item->content.ptr;    sym= CAR(env->head)->content.ptr;
   
   /* if the symbol was bound to something else, throw it away */  
   if(sym->val != NULL)  
     free_val(sym->val);  
858    
859    /* Bind the symbol to the value */    /* Bind the symbol to the value */
860    sym->val= env->head->next->item;    sym->val= CAR(CDR(env->head));
   sym->val->refcount++;         /* Increase the reference counter */  
861    
862    toss(env); toss(env);    toss(env); toss(env);
863  }  }
# Line 716  extern void def(environment *env) Line 865  extern void def(environment *env)
865  /* Quit stack. */  /* Quit stack. */
866  extern void quit(environment *env)  extern void quit(environment *env)
867  {  {
868      int i;
869    
870      clear(env);
871    
872      if (env->err) return;
873      for(i= 0; i<HASHTBLSIZE; i++) {
874        while(env->symbols[i]!= NULL) {
875          forget_sym(&(env->symbols[i]));
876        }
877        env->symbols[i]= NULL;
878      }
879    
880      env->gc_limit= 0;
881      gc_maybe(env);
882    
883      if(env->free_string!=NULL)
884        free(env->free_string);
885      
886      muntrace();
887    
888    exit(EXIT_SUCCESS);    exit(EXIT_SUCCESS);
889  }  }
890    
# Line 741  extern void words(environment *env) Line 910  extern void words(environment *env)
910    }    }
911  }  }
912    
913    /* Internal forget function */
914    void forget_sym(symbol **hash_entry)
915    {
916      symbol *temp;
917    
918      temp= *hash_entry;
919      *hash_entry= (*hash_entry)->next;
920      
921      free(temp->id);
922      free(temp);
923    }
924    
925  /* Forgets a symbol (remove it from the hash table) */  /* Forgets a symbol (remove it from the hash table) */
926  extern void forget(environment *env)  extern void forget(environment *env)
927  {  {
928    char* sym_id;    char* sym_id;
929    stackitem *stack_head= env->head;    value *stack_head= env->head;
   symbol **hash_entry, *temp;  
930    
931    if(stack_head==NULL) {    if(stack_head==NULL) {
932      printerr("Too Few Arguments");      printerr("Too Few Arguments");
933      env->err=1;      env->err= 1;
934      return;      return;
935    }    }
936        
937    if(stack_head->item->type!=symb) {    if(CAR(stack_head)->type!=symb) {
938      printerr("Bad Argument Type");      printerr("Bad Argument Type");
939      env->err=2;      env->err= 2;
940      return;      return;
941    }    }
942    
943    sym_id= ((symbol*)(stack_head->item->content.ptr))->id;    sym_id= CAR(stack_head)->content.sym->id;
944    toss(env);    toss(env);
945    
946    hash_entry= hash(env->symbols, sym_id);    return forget_sym(hash(env->symbols, sym_id));
   temp= *hash_entry;  
   *hash_entry= (*hash_entry)->next;  
     
   if(temp->val!=NULL) {  
     free_val(temp->val);  
   }  
   free(temp->id);  
   free(temp);  
947  }  }
948    
949  /* Returns the current error number to the stack */  /* Returns the current error number to the stack */
950  extern void errn(environment *env){  extern void errn(environment *env)
951    push_int(&(env->head), env->err);  {
952      push_int(env, env->err);
953  }  }
954    
955  int main()  int main(int argc, char **argv)
956  {  {
957    environment myenv;    environment myenv;
958    char in_string[100];  
959      int c;                        /* getopt option character */
960    
961      mtrace();
962    
963    init_env(&myenv);    init_env(&myenv);
964    
965    printf("okidok\n ");    myenv.interactive = isatty(STDIN_FILENO) && isatty(STDOUT_FILENO);
966    
967      while ((c = getopt (argc, argv, "i")) != -1)
968        switch (c)
969          {
970          case 'i':
971            myenv.interactive = 1;
972            break;
973          case '?':
974            fprintf (stderr,
975                     "Unknown option character `\\x%x'.\n",
976                     optopt);
977            return EX_USAGE;
978          default:
979            abort ();
980          }
981      
982      if (optind < argc) {
983        myenv.interactive = 0;
984        myenv.inputstream= fopen(argv[optind], "r");
985        if(myenv.inputstream== NULL) {
986          perror(argv[0]);
987          exit (EX_NOINPUT);
988        }
989      }
990    
991      if(myenv.interactive) {
992        printf("Stack version $Revision$\n\
993    Copyright (C) 2002  Mats Alritzson and Teddy Hogeborn\n\
994    Stack comes with ABSOLUTELY NO WARRANTY; for details type `warranty;'.\n\
995    This is free software, and you are welcome to redistribute it\n\
996    under certain conditions; type `copying;' for details.\n");
997      }
998    
999    while(fgets(in_string, 100, stdin) != NULL) {    while(1) {
1000      stack_read(&myenv, in_string);      if(myenv.in_string==NULL) {
1001      if(myenv.err) {        if (myenv.interactive) {
1002        printf("(error %d) ", myenv.err);          if(myenv.err) {
1003              printf("(error %d)\n", myenv.err);
1004            }
1005            nl();
1006            printstack(&myenv);
1007            printf("> ");
1008          }
1009        myenv.err=0;        myenv.err=0;
1010      }      }
1011      printf("okidok\n ");      sx_72656164(&myenv);
1012        if (myenv.err==4) {
1013          return EXIT_SUCCESS;      /* EOF */
1014        } else if(myenv.head!=NULL
1015                  && CAR(myenv.head)->type==symb
1016                  && CAR(myenv.head)->content.sym->id[0]
1017                  ==';') {
1018          toss(&myenv);             /* No error check in main */
1019          eval(&myenv);
1020        }
1021        gc_maybe(&myenv);
1022    }    }
1023      quit(&myenv);
1024      return EXIT_FAILURE;
1025    }
1026    
1027    exit(EXIT_SUCCESS);  /* "+" */
1028    extern void sx_2b(environment *env)
1029    {
1030      int a, b;
1031      float fa, fb;
1032      size_t len;
1033      char* new_string;
1034      value *a_val, *b_val;
1035    
1036      if(env->head==NULL || CDR(env->head)==NULL) {
1037        printerr("Too Few Arguments");
1038        env->err= 1;
1039        return;
1040      }
1041    
1042      if(CAR(env->head)->type==string
1043         && CAR(CDR(env->head))->type==string) {
1044        a_val= CAR(env->head);
1045        b_val= CAR(CDR(env->head));
1046        protect(a_val); protect(b_val);
1047        toss(env); if(env->err) return;
1048        toss(env); if(env->err) return;
1049        len= strlen(a_val->content.ptr)+strlen(b_val->content.ptr)+1;
1050        new_string= malloc(len);
1051        strcpy(new_string, b_val->content.ptr);
1052        strcat(new_string, a_val->content.ptr);
1053        push_cstring(env, new_string);
1054        unprotect(a_val); unprotect(b_val);
1055        free(new_string);
1056        
1057        return;
1058      }
1059      
1060      if(CAR(env->head)->type==integer
1061         && CAR(CDR(env->head))->type==integer) {
1062        a= CAR(env->head)->content.i;
1063        toss(env); if(env->err) return;
1064        b= CAR(env->head)->content.i;
1065        toss(env); if(env->err) return;
1066        push_int(env, b+a);
1067    
1068        return;
1069      }
1070    
1071      if(CAR(env->head)->type==tfloat
1072         && CAR(CDR(env->head))->type==tfloat) {
1073        fa= CAR(env->head)->content.f;
1074        toss(env); if(env->err) return;
1075        fb= CAR(env->head)->content.f;
1076        toss(env); if(env->err) return;
1077        push_float(env, fb+fa);
1078        
1079        return;
1080      }
1081    
1082      if(CAR(env->head)->type==tfloat
1083         && CAR(CDR(env->head))->type==integer) {
1084        fa= CAR(env->head)->content.f;
1085        toss(env); if(env->err) return;
1086        b= CAR(env->head)->content.i;
1087        toss(env); if(env->err) return;
1088        push_float(env, b+fa);
1089        
1090        return;
1091      }
1092    
1093      if(CAR(env->head)->type==integer
1094         && CAR(CDR(env->head))->type==tfloat) {
1095        a= CAR(env->head)->content.i;
1096        toss(env); if(env->err) return;
1097        fb= CAR(env->head)->content.f;
1098        toss(env); if(env->err) return;
1099        push_float(env, fb+a);
1100    
1101        return;
1102      }
1103    
1104      printerr("Bad Argument Type");
1105      env->err=2;
1106    }
1107    
1108    /* "-" */
1109    extern void sx_2d(environment *env)
1110    {
1111      int a, b;
1112      float fa, fb;
1113    
1114      if(env->head==NULL || CDR(env->head)==NULL) {
1115        printerr("Too Few Arguments");
1116        env->err=1;
1117        return;
1118      }
1119      
1120      if(CAR(env->head)->type==integer
1121         && CAR(CDR(env->head))->type==integer) {
1122        a= CAR(env->head)->content.i;
1123        toss(env); if(env->err) return;
1124        b= CAR(env->head)->content.i;
1125        toss(env); if(env->err) return;
1126        push_int(env, b-a);
1127    
1128        return;
1129      }
1130    
1131      if(CAR(env->head)->type==tfloat
1132         && CAR(CDR(env->head))->type==tfloat) {
1133        fa= CAR(env->head)->content.f;
1134        toss(env); if(env->err) return;
1135        fb= CAR(env->head)->content.f;
1136        toss(env); if(env->err) return;
1137        push_float(env, fb-fa);
1138        
1139        return;
1140      }
1141    
1142      if(CAR(env->head)->type==tfloat
1143         && CAR(CDR(env->head))->type==integer) {
1144        fa= CAR(env->head)->content.f;
1145        toss(env); if(env->err) return;
1146        b= CAR(env->head)->content.i;
1147        toss(env); if(env->err) return;
1148        push_float(env, b-fa);
1149        
1150        return;
1151      }
1152    
1153      if(CAR(env->head)->type==integer
1154         && CAR(CDR(env->head))->type==tfloat) {
1155        a= CAR(env->head)->content.i;
1156        toss(env); if(env->err) return;
1157        fb= CAR(env->head)->content.f;
1158        toss(env); if(env->err) return;
1159        push_float(env, fb-a);
1160    
1161        return;
1162      }
1163    
1164      printerr("Bad Argument Type");
1165      env->err=2;
1166    }
1167    
1168    /* ">" */
1169    extern void sx_3e(environment *env)
1170    {
1171      int a, b;
1172      float fa, fb;
1173    
1174      if(env->head==NULL || CDR(env->head)==NULL) {
1175        printerr("Too Few Arguments");
1176        env->err= 1;
1177        return;
1178      }
1179      
1180      if(CAR(env->head)->type==integer
1181         && CAR(CDR(env->head))->type==integer) {
1182        a= CAR(env->head)->content.i;
1183        toss(env); if(env->err) return;
1184        b= CAR(env->head)->content.i;
1185        toss(env); if(env->err) return;
1186        push_int(env, b>a);
1187    
1188        return;
1189      }
1190    
1191      if(CAR(env->head)->type==tfloat
1192         && CAR(CDR(env->head))->type==tfloat) {
1193        fa= CAR(env->head)->content.f;
1194        toss(env); if(env->err) return;
1195        fb= CAR(env->head)->content.f;
1196        toss(env); if(env->err) return;
1197        push_int(env, fb>fa);
1198        
1199        return;
1200      }
1201    
1202      if(CAR(env->head)->type==tfloat
1203         && CAR(CDR(env->head))->type==integer) {
1204        fa= CAR(env->head)->content.f;
1205        toss(env); if(env->err) return;
1206        b= CAR(env->head)->content.i;
1207        toss(env); if(env->err) return;
1208        push_int(env, b>fa);
1209        
1210        return;
1211      }
1212    
1213      if(CAR(env->head)->type==integer
1214         && CAR(CDR(env->head))->type==tfloat) {
1215        a= CAR(env->head)->content.i;
1216        toss(env); if(env->err) return;
1217        fb= CAR(env->head)->content.f;
1218        toss(env); if(env->err) return;
1219        push_int(env, fb>a);
1220    
1221        return;
1222      }
1223    
1224      printerr("Bad Argument Type");
1225      env->err= 2;
1226    }
1227    
1228    /* "<" */
1229    extern void sx_3c(environment *env)
1230    {
1231      swap(env); if(env->err) return;
1232      sx_3e(env);
1233    }
1234    
1235    /* "<=" */
1236    extern void sx_3c3d(environment *env)
1237    {
1238      sx_3e(env); if(env->err) return;
1239      not(env);
1240    }
1241    
1242    /* ">=" */
1243    extern void sx_3e3d(environment *env)
1244    {
1245      sx_3c(env); if(env->err) return;
1246      not(env);
1247    }
1248    
1249    /* Return copy of a value */
1250    value *copy_val(environment *env, value *old_value)
1251    {
1252      value *new_value;
1253    
1254      if(old_value==NULL)
1255        return NULL;
1256    
1257      protect(old_value);
1258      new_value= new_val(env);
1259      protect(new_value);
1260      new_value->type= old_value->type;
1261    
1262      switch(old_value->type){
1263      case tfloat:
1264      case integer:
1265      case func:
1266      case symb:
1267        new_value->content= old_value->content;
1268        break;
1269      case string:
1270        (char *)(new_value->content.ptr)=
1271          strdup((char *)(old_value->content.ptr));
1272        break;
1273      case tcons:
1274        new_value= NULL;
1275    
1276        new_value->content.c= malloc(sizeof(cons));
1277        CAR(new_value)= copy_val(env, CAR(old_value)); /* recurse */
1278        CDR(new_value)= copy_val(env, CDR(old_value)); /* recurse */
1279        break;
1280      }
1281    
1282      unprotect(old_value); unprotect(new_value);
1283    
1284      return new_value;
1285    }
1286    
1287    /* "dup"; duplicates an item on the stack */
1288    extern void sx_647570(environment *env)
1289    {
1290      if(env->head==NULL) {
1291        printerr("Too Few Arguments");
1292        env->err= 1;
1293        return;
1294      }
1295      push_val(env, copy_val(env, CAR(env->head)));
1296    }
1297    
1298    /* "if", If-Then */
1299    extern void sx_6966(environment *env)
1300    {
1301      int truth;
1302    
1303      if(env->head==NULL || CDR(env->head)==NULL) {
1304        printerr("Too Few Arguments");
1305        env->err= 1;
1306        return;
1307      }
1308    
1309      if(CAR(CDR(env->head))->type != integer) {
1310        printerr("Bad Argument Type");
1311        env->err= 2;
1312        return;
1313      }
1314      
1315      swap(env);
1316      if(env->err) return;
1317      
1318      truth= CAR(env->head)->content.i;
1319    
1320      toss(env);
1321      if(env->err) return;
1322    
1323      if(truth)
1324        eval(env);
1325      else
1326        toss(env);
1327    }
1328    
1329    /* If-Then-Else */
1330    extern void ifelse(environment *env)
1331    {
1332      int truth;
1333    
1334      if(env->head==NULL || CDR(env->head)==NULL
1335         || CDR(CDR(env->head))==NULL) {
1336        printerr("Too Few Arguments");
1337        env->err= 1;
1338        return;
1339      }
1340    
1341      if(CAR(CDR(CDR(env->head)))->type!=integer) {
1342        printerr("Bad Argument Type");
1343        env->err= 2;
1344        return;
1345      }
1346      
1347      rot(env);
1348      if(env->err) return;
1349      
1350      truth= CAR(env->head)->content.i;
1351    
1352      toss(env);
1353      if(env->err) return;
1354    
1355      if(!truth)
1356        swap(env);
1357      if(env->err) return;
1358    
1359      toss(env);
1360      if(env->err) return;
1361    
1362      eval(env);
1363    }
1364    
1365    /* "while" */
1366    extern void sx_7768696c65(environment *env)
1367    {
1368      int truth;
1369      value *loop, *test;
1370    
1371      if(env->head==NULL || CDR(env->head)==NULL) {
1372        printerr("Too Few Arguments");
1373        env->err= 1;
1374        return;
1375      }
1376    
1377      loop= CAR(env->head);
1378      protect(loop);
1379      toss(env); if(env->err) return;
1380    
1381      test= CAR(env->head);
1382      protect(test);
1383      toss(env); if(env->err) return;
1384    
1385      do {
1386        push_val(env, test);
1387        eval(env);
1388        
1389        if(CAR(env->head)->type != integer) {
1390          printerr("Bad Argument Type");
1391          env->err= 2;
1392          return;
1393        }
1394        
1395        truth= CAR(env->head)->content.i;
1396        toss(env); if(env->err) return;
1397        
1398        if(truth) {
1399          push_val(env, loop);
1400          eval(env);
1401        } else {
1402          toss(env);
1403        }
1404      
1405      } while(truth);
1406    
1407      unprotect(loop); unprotect(test);
1408    }
1409    
1410    
1411    /* "for"; for-loop */
1412    extern void sx_666f72(environment *env)
1413    {
1414      value *loop;
1415      int foo1, foo2;
1416    
1417      if(env->head==NULL || CDR(env->head)==NULL
1418         || CDR(CDR(env->head))==NULL) {
1419        printerr("Too Few Arguments");
1420        env->err= 1;
1421        return;
1422      }
1423    
1424      if(CAR(CDR(env->head))->type!=integer
1425         || CAR(CDR(CDR(env->head)))->type!=integer) {
1426        printerr("Bad Argument Type");
1427        env->err= 2;
1428        return;
1429      }
1430    
1431      loop= CAR(env->head);
1432      protect(loop);
1433      toss(env); if(env->err) return;
1434    
1435      foo2= CAR(env->head)->content.i;
1436      toss(env); if(env->err) return;
1437    
1438      foo1= CAR(env->head)->content.i;
1439      toss(env); if(env->err) return;
1440    
1441      if(foo1<=foo2) {
1442        while(foo1<=foo2) {
1443          push_int(env, foo1);
1444          push_val(env, loop);
1445          eval(env); if(env->err) return;
1446          foo1++;
1447        }
1448      } else {
1449        while(foo1>=foo2) {
1450          push_int(env, foo1);
1451          push_val(env, loop);
1452          eval(env); if(env->err) return;
1453          foo1--;
1454        }
1455      }
1456      unprotect(loop);
1457    }
1458    
1459    /* Variant of for-loop */
1460    extern void foreach(environment *env)
1461    {  
1462      value *loop, *foo;
1463      value *iterator;
1464      
1465      if(env->head==NULL || CDR(env->head)==NULL) {
1466        printerr("Too Few Arguments");
1467        env->err= 1;
1468        return;
1469      }
1470    
1471      if(CAR(CDR(env->head))->type!=tcons) {
1472        printerr("Bad Argument Type");
1473        env->err= 2;
1474        return;
1475      }
1476    
1477      loop= CAR(env->head);
1478      protect(loop);
1479      toss(env); if(env->err) return;
1480    
1481      foo= CAR(env->head);
1482      protect(foo);
1483      toss(env); if(env->err) return;
1484    
1485      iterator= foo;
1486    
1487      while(iterator!=NULL) {
1488        push_val(env, CAR(iterator));
1489        push_val(env, loop);
1490        eval(env); if(env->err) return;
1491        if (iterator->type == tcons){
1492          iterator= CDR(iterator);
1493        } else {
1494          printerr("Bad Argument Type"); /* Improper list */
1495          env->err= 2;
1496          break;
1497        }
1498      }
1499      unprotect(loop); unprotect(foo);
1500    }
1501    
1502    /* "to" */
1503    extern void to(environment *env)
1504    {
1505      int ending, start, i;
1506      value *iterator, *temp;
1507    
1508      if(env->head==NULL || CDR(env->head)==NULL) {
1509        printerr("Too Few Arguments");
1510        env->err= 1;
1511        return;
1512      }
1513    
1514      if(CAR(env->head)->type!=integer
1515         || CAR(CDR(env->head))->type!=integer) {
1516        printerr("Bad Argument Type");
1517        env->err= 2;
1518        return;
1519      }
1520    
1521      ending= CAR(env->head)->content.i;
1522      toss(env); if(env->err) return;
1523      start= CAR(env->head)->content.i;
1524      toss(env); if(env->err) return;
1525    
1526      push_sym(env, "[");
1527    
1528      if(ending>=start) {
1529        for(i= ending; i>=start; i--)
1530          push_int(env, i);
1531      } else {
1532        for(i= ending; i<=start; i++)
1533          push_int(env, i);
1534      }
1535    
1536      iterator= env->head;
1537    
1538      if(iterator==NULL
1539         || (CAR(iterator)->type==symb
1540             && CAR(iterator)->content.sym->id[0]=='[')) {
1541        temp= NULL;
1542        toss(env);
1543      } else {
1544        /* Search for first delimiter */
1545        while(CDR(iterator)!=NULL
1546              && (CAR(CDR(iterator))->type!=symb
1547                  || CAR(CDR(iterator))->content.sym->id[0]!='['))
1548          iterator= CDR(iterator);
1549        
1550        /* Extract list */
1551        temp= env->head;
1552        env->head= CDR(iterator);
1553        CDR(iterator)= NULL;
1554    
1555        if(env->head!=NULL)
1556          toss(env);
1557      }
1558    
1559      /* Push list */
1560      push_val(env, temp);
1561    }
1562    
1563    /* Read a string */
1564    extern void readline(environment *env)
1565    {
1566      char in_string[101];
1567    
1568      if(fgets(in_string, 100, env->inputstream)==NULL)
1569        push_cstring(env, "");
1570      else
1571        push_cstring(env, in_string);
1572    }
1573    
1574    /* "read"; Read a value and place on stack */
1575    extern void sx_72656164(environment *env)
1576    {
1577      const char symbform[]= "%[a-zA-Z0-9!$%*+./:<=>?@^_~-]%n";
1578      const char strform[]= "\"%[^\"]\"%n";
1579      const char intform[]= "%i%n";
1580      const char fltform[]= "%f%n";
1581      const char blankform[]= "%*[ \t]%n";
1582      const char ebrackform[]= "]%n";
1583      const char semicform[]= ";%n";
1584      const char bbrackform[]= "[%n";
1585    
1586      int itemp, readlength= -1;
1587      int count= -1;
1588      float ftemp;
1589      static int depth= 0;
1590      char *match, *ctemp;
1591      size_t inlength;
1592    
1593      if(env->in_string==NULL) {
1594        if(depth > 0 && env->interactive) {
1595          printf("]> ");
1596        }
1597        readline(env); if(env->err) return;
1598    
1599        if(((char *)(CAR(env->head)->content.ptr))[0]=='\0'){
1600          env->err= 4;              /* "" means EOF */
1601          return;
1602        }
1603        
1604        env->in_string= malloc(strlen(CAR(env->head)->content.ptr)+1);
1605        env->free_string= env->in_string; /* Save the original pointer */
1606        strcpy(env->in_string, CAR(env->head)->content.ptr);
1607        toss(env); if(env->err) return;
1608      }
1609      
1610      inlength= strlen(env->in_string)+1;
1611      match= malloc(inlength);
1612    
1613      if(sscanf(env->in_string, blankform, &readlength) != EOF
1614         && readlength != -1) {
1615        ;
1616      } else if(sscanf(env->in_string, fltform, &ftemp, &readlength) != EOF
1617                && readlength != -1) {
1618        if(sscanf(env->in_string, intform, &itemp, &count) != EOF
1619           && count==readlength) {
1620          push_int(env, itemp);
1621        } else {
1622          push_float(env, ftemp);
1623        }
1624      } else if(sscanf(env->in_string, strform, match, &readlength) != EOF
1625                && readlength != -1) {
1626        push_cstring(env, match);
1627      } else if(sscanf(env->in_string, symbform, match, &readlength) != EOF
1628                && readlength != -1) {
1629        push_sym(env, match);
1630      } else if(sscanf(env->in_string, ebrackform, &readlength) != EOF
1631                && readlength != -1) {
1632        pack(env); if(env->err) return;
1633        if(depth != 0) depth--;
1634      } else if(sscanf(env->in_string, semicform, &readlength) != EOF
1635                && readlength != -1) {
1636        push_sym(env, ";");
1637      } else if(sscanf(env->in_string, bbrackform, &readlength) != EOF
1638                && readlength != -1) {
1639        push_sym(env, "[");
1640        depth++;
1641      } else {
1642        free(env->free_string);
1643        env->in_string = env->free_string = NULL;
1644      }
1645      if (env->in_string != NULL) {
1646        env->in_string += readlength;
1647      }
1648    
1649      free(match);
1650    
1651      if(depth)
1652        return sx_72656164(env);
1653    }
1654    
1655    extern void beep(environment *env)
1656    {
1657      int freq, dur, period, ticks;
1658    
1659      if(env->head==NULL || CDR(env->head)==NULL) {
1660        printerr("Too Few Arguments");
1661        env->err= 1;
1662        return;
1663      }
1664    
1665      if(CAR(env->head)->type!=integer
1666         || CAR(CDR(env->head))->type!=integer) {
1667        printerr("Bad Argument Type");
1668        env->err= 2;
1669        return;
1670      }
1671    
1672      dur= CAR(env->head)->content.i;
1673      toss(env);
1674      freq= CAR(env->head)->content.i;
1675      toss(env);
1676    
1677      period= 1193180/freq;         /* convert freq from Hz to period
1678                                       length */
1679      ticks= dur*.001193180;        /* convert duration from µseconds to
1680                                       timer ticks */
1681    
1682    /*    ticks=dur/1000; */
1683    
1684          /*  if (ioctl(STDOUT_FILENO, KDMKTONE, (125<<16) + 0x637)==0) */
1685      switch (ioctl(STDOUT_FILENO, KDMKTONE, (ticks<<16) | period)){
1686      case 0:
1687        usleep(dur);
1688        return;
1689      case -1:
1690        perror("beep");
1691        env->err= 5;
1692        return;
1693      default:
1694        abort();
1695      }
1696    }
1697    
1698    /* "wait" */
1699    extern void sx_77616974(environment *env)
1700    {
1701      int dur;
1702    
1703      if(env->head==NULL) {
1704        printerr("Too Few Arguments");
1705        env->err= 1;
1706        return;
1707      }
1708    
1709      if(CAR(env->head)->type!=integer) {
1710        printerr("Bad Argument Type");
1711        env->err= 2;
1712        return;
1713      }
1714    
1715      dur= CAR(env->head)->content.i;
1716      toss(env);
1717    
1718      usleep(dur);
1719    }
1720    
1721    extern void copying(environment *env)
1722    {
1723      printf("GNU GENERAL PUBLIC LICENSE\n\
1724                           Version 2, June 1991\n\
1725    \n\
1726     Copyright (C) 1989, 1991 Free Software Foundation, Inc.\n\
1727         59 Temple Place, Suite 330, Boston, MA  02111-1307  USA\n\
1728     Everyone is permitted to copy and distribute verbatim copies\n\
1729     of this license document, but changing it is not allowed.\n\
1730    \n\
1731                                Preamble\n\
1732    \n\
1733      The licenses for most software are designed to take away your\n\
1734    freedom to share and change it.  By contrast, the GNU General Public\n\
1735    License is intended to guarantee your freedom to share and change free\n\
1736    software--to make sure the software is free for all its users.  This\n\
1737    General Public License applies to most of the Free Software\n\
1738    Foundation's software and to any other program whose authors commit to\n\
1739    using it.  (Some other Free Software Foundation software is covered by\n\
1740    the GNU Library General Public License instead.)  You can apply it to\n\
1741    your programs, too.\n\
1742    \n\
1743      When we speak of free software, we are referring to freedom, not\n\
1744    price.  Our General Public Licenses are designed to make sure that you\n\
1745    have the freedom to distribute copies of free software (and charge for\n\
1746    this service if you wish), that you receive source code or can get it\n\
1747    if you want it, that you can change the software or use pieces of it\n\
1748    in new free programs; and that you know you can do these things.\n\
1749    \n\
1750      To protect your rights, we need to make restrictions that forbid\n\
1751    anyone to deny you these rights or to ask you to surrender the rights.\n\
1752    These restrictions translate to certain responsibilities for you if you\n\
1753    distribute copies of the software, or if you modify it.\n\
1754    \n\
1755      For example, if you distribute copies of such a program, whether\n\
1756    gratis or for a fee, you must give the recipients all the rights that\n\
1757    you have.  You must make sure that they, too, receive or can get the\n\
1758    source code.  And you must show them these terms so they know their\n\
1759    rights.\n\
1760    \n\
1761      We protect your rights with two steps: (1) copyright the software, and\n\
1762    (2) offer you this license which gives you legal permission to copy,\n\
1763    distribute and/or modify the software.\n\
1764    \n\
1765      Also, for each author's protection and ours, we want to make certain\n\
1766    that everyone understands that there is no warranty for this free\n\
1767    software.  If the software is modified by someone else and passed on, we\n\
1768    want its recipients to know that what they have is not the original, so\n\
1769    that any problems introduced by others will not reflect on the original\n\
1770    authors' reputations.\n\
1771    \n\
1772      Finally, any free program is threatened constantly by software\n\
1773    patents.  We wish to avoid the danger that redistributors of a free\n\
1774    program will individually obtain patent licenses, in effect making the\n\
1775    program proprietary.  To prevent this, we have made it clear that any\n\
1776    patent must be licensed for everyone's free use or not licensed at all.\n\
1777    \n\
1778      The precise terms and conditions for copying, distribution and\n\
1779    modification follow.\n\
1780    \n\
1781                        GNU GENERAL PUBLIC LICENSE\n\
1782       TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION\n\
1783    \n\
1784      0. This License applies to any program or other work which contains\n\
1785    a notice placed by the copyright holder saying it may be distributed\n\
1786    under the terms of this General Public License.  The \"Program\", below,\n\
1787    refers to any such program or work, and a \"work based on the Program\"\n\
1788    means either the Program or any derivative work under copyright law:\n\
1789    that is to say, a work containing the Program or a portion of it,\n\
1790    either verbatim or with modifications and/or translated into another\n\
1791    language.  (Hereinafter, translation is included without limitation in\n\
1792    the term \"modification\".)  Each licensee is addressed as \"you\".\n\
1793    \n\
1794    Activities other than copying, distribution and modification are not\n\
1795    covered by this License; they are outside its scope.  The act of\n\
1796    running the Program is not restricted, and the output from the Program\n\
1797    is covered only if its contents constitute a work based on the\n\
1798    Program (independent of having been made by running the Program).\n\
1799    Whether that is true depends on what the Program does.\n\
1800    \n\
1801      1. You may copy and distribute verbatim copies of the Program's\n\
1802    source code as you receive it, in any medium, provided that you\n\
1803    conspicuously and appropriately publish on each copy an appropriate\n\
1804    copyright notice and disclaimer of warranty; keep intact all the\n\
1805    notices that refer to this License and to the absence of any warranty;\n\
1806    and give any other recipients of the Program a copy of this License\n\
1807    along with the Program.\n\
1808    \n\
1809    You may charge a fee for the physical act of transferring a copy, and\n\
1810    you may at your option offer warranty protection in exchange for a fee.\n\
1811    \n\
1812      2. You may modify your copy or copies of the Program or any portion\n\
1813    of it, thus forming a work based on the Program, and copy and\n\
1814    distribute such modifications or work under the terms of Section 1\n\
1815    above, provided that you also meet all of these conditions:\n\
1816    \n\
1817        a) You must cause the modified files to carry prominent notices\n\
1818        stating that you changed the files and the date of any change.\n\
1819    \n\
1820        b) You must cause any work that you distribute or publish, that in\n\
1821        whole or in part contains or is derived from the Program or any\n\
1822        part thereof, to be licensed as a whole at no charge to all third\n\
1823        parties under the terms of this License.\n\
1824    \n\
1825        c) If the modified program normally reads commands interactively\n\
1826        when run, you must cause it, when started running for such\n\
1827        interactive use in the most ordinary way, to print or display an\n\
1828        announcement including an appropriate copyright notice and a\n\
1829        notice that there is no warranty (or else, saying that you provide\n\
1830        a warranty) and that users may redistribute the program under\n\
1831        these conditions, and telling the user how to view a copy of this\n\
1832        License.  (Exception: if the Program itself is interactive but\n\
1833        does not normally print such an announcement, your work based on\n\
1834        the Program is not required to print an announcement.)\n\
1835    \n\
1836    These requirements apply to the modified work as a whole.  If\n\
1837    identifiable sections of that work are not derived from the Program,\n\
1838    and can be reasonably considered independent and separate works in\n\
1839    themselves, then this License, and its terms, do not apply to those\n\
1840    sections when you distribute them as separate works.  But when you\n\
1841    distribute the same sections as part of a whole which is a work based\n\
1842    on the Program, the distribution of the whole must be on the terms of\n\
1843    this License, whose permissions for other licensees extend to the\n\
1844    entire whole, and thus to each and every part regardless of who wrote it.\n\
1845    \n\
1846    Thus, it is not the intent of this section to claim rights or contest\n\
1847    your rights to work written entirely by you; rather, the intent is to\n\
1848    exercise the right to control the distribution of derivative or\n\
1849    collective works based on the Program.\n\
1850    \n\
1851    In addition, mere aggregation of another work not based on the Program\n\
1852    with the Program (or with a work based on the Program) on a volume of\n\
1853    a storage or distribution medium does not bring the other work under\n\
1854    the scope of this License.\n\
1855    \n\
1856      3. You may copy and distribute the Program (or a work based on it,\n\
1857    under Section 2) in object code or executable form under the terms of\n\
1858    Sections 1 and 2 above provided that you also do one of the following:\n\
1859    \n\
1860        a) Accompany it with the complete corresponding machine-readable\n\
1861        source code, which must be distributed under the terms of Sections\n\
1862        1 and 2 above on a medium customarily used for software interchange; or,\n\
1863    \n\
1864        b) Accompany it with a written offer, valid for at least three\n\
1865        years, to give any third party, for a charge no more than your\n\
1866        cost of physically performing source distribution, a complete\n\
1867        machine-readable copy of the corresponding source code, to be\n\
1868        distributed under the terms of Sections 1 and 2 above on a medium\n\
1869        customarily used for software interchange; or,\n\
1870    \n\
1871        c) Accompany it with the information you received as to the offer\n\
1872        to distribute corresponding source code.  (This alternative is\n\
1873        allowed only for noncommercial distribution and only if you\n\
1874        received the program in object code or executable form with such\n\
1875        an offer, in accord with Subsection b above.)\n\
1876    \n\
1877    The source code for a work means the preferred form of the work for\n\
1878    making modifications to it.  For an executable work, complete source\n\
1879    code means all the source code for all modules it contains, plus any\n\
1880    associated interface definition files, plus the scripts used to\n\
1881    control compilation and installation of the executable.  However, as a\n\
1882    special exception, the source code distributed need not include\n\
1883    anything that is normally distributed (in either source or binary\n\
1884    form) with the major components (compiler, kernel, and so on) of the\n\
1885    operating system on which the executable runs, unless that component\n\
1886    itself accompanies the executable.\n\
1887    \n\
1888    If distribution of executable or object code is made by offering\n\
1889    access to copy from a designated place, then offering equivalent\n\
1890    access to copy the source code from the same place counts as\n\
1891    distribution of the source code, even though third parties are not\n\
1892    compelled to copy the source along with the object code.\n\
1893    \n\
1894      4. You may not copy, modify, sublicense, or distribute the Program\n\
1895    except as expressly provided under this License.  Any attempt\n\
1896    otherwise to copy, modify, sublicense or distribute the Program is\n\
1897    void, and will automatically terminate your rights under this License.\n\
1898    However, parties who have received copies, or rights, from you under\n\
1899    this License will not have their licenses terminated so long as such\n\
1900    parties remain in full compliance.\n\
1901    \n\
1902      5. You are not required to accept this License, since you have not\n\
1903    signed it.  However, nothing else grants you permission to modify or\n\
1904    distribute the Program or its derivative works.  These actions are\n\
1905    prohibited by law if you do not accept this License.  Therefore, by\n\
1906    modifying or distributing the Program (or any work based on the\n\
1907    Program), you indicate your acceptance of this License to do so, and\n\
1908    all its terms and conditions for copying, distributing or modifying\n\
1909    the Program or works based on it.\n\
1910    \n\
1911      6. Each time you redistribute the Program (or any work based on the\n\
1912    Program), the recipient automatically receives a license from the\n\
1913    original licensor to copy, distribute or modify the Program subject to\n\
1914    these terms and conditions.  You may not impose any further\n\
1915    restrictions on the recipients' exercise of the rights granted herein.\n\
1916    You are not responsible for enforcing compliance by third parties to\n\
1917    this License.\n\
1918    \n\
1919      7. If, as a consequence of a court judgment or allegation of patent\n\
1920    infringement or for any other reason (not limited to patent issues),\n\
1921    conditions are imposed on you (whether by court order, agreement or\n\
1922    otherwise) that contradict the conditions of this License, they do not\n\
1923    excuse you from the conditions of this License.  If you cannot\n\
1924    distribute so as to satisfy simultaneously your obligations under this\n\
1925    License and any other pertinent obligations, then as a consequence you\n\
1926    may not distribute the Program at all.  For example, if a patent\n\
1927    license would not permit royalty-free redistribution of the Program by\n\
1928    all those who receive copies directly or indirectly through you, then\n\
1929    the only way you could satisfy both it and this License would be to\n\
1930    refrain entirely from distribution of the Program.\n\
1931    \n\
1932    If any portion of this section is held invalid or unenforceable under\n\
1933    any particular circumstance, the balance of the section is intended to\n\
1934    apply and the section as a whole is intended to apply in other\n\
1935    circumstances.\n\
1936    \n\
1937    It is not the purpose of this section to induce you to infringe any\n\
1938    patents or other property right claims or to contest validity of any\n\
1939    such claims; this section has the sole purpose of protecting the\n\
1940    integrity of the free software distribution system, which is\n\
1941    implemented by public license practices.  Many people have made\n\
1942    generous contributions to the wide range of software distributed\n\
1943    through that system in reliance on consistent application of that\n\
1944    system; it is up to the author/donor to decide if he or she is willing\n\
1945    to distribute software through any other system and a licensee cannot\n\
1946    impose that choice.\n\
1947    \n\
1948    This section is intended to make thoroughly clear what is believed to\n\
1949    be a consequence of the rest of this License.\n\
1950    \n\
1951      8. If the distribution and/or use of the Program is restricted in\n\
1952    certain countries either by patents or by copyrighted interfaces, the\n\
1953    original copyright holder who places the Program under this License\n\
1954    may add an explicit geographical distribution limitation excluding\n\
1955    those countries, so that distribution is permitted only in or among\n\
1956    countries not thus excluded.  In such case, this License incorporates\n\
1957    the limitation as if written in the body of this License.\n\
1958    \n\
1959      9. The Free Software Foundation may publish revised and/or new versions\n\
1960    of the General Public License from time to time.  Such new versions will\n\
1961    be similar in spirit to the present version, but may differ in detail to\n\
1962    address new problems or concerns.\n\
1963    \n\
1964    Each version is given a distinguishing version number.  If the Program\n\
1965    specifies a version number of this License which applies to it and \"any\n\
1966    later version\", you have the option of following the terms and conditions\n\
1967    either of that version or of any later version published by the Free\n\
1968    Software Foundation.  If the Program does not specify a version number of\n\
1969    this License, you may choose any version ever published by the Free Software\n\
1970    Foundation.\n\
1971    \n\
1972      10. If you wish to incorporate parts of the Program into other free\n\
1973    programs whose distribution conditions are different, write to the author\n\
1974    to ask for permission.  For software which is copyrighted by the Free\n\
1975    Software Foundation, write to the Free Software Foundation; we sometimes\n\
1976    make exceptions for this.  Our decision will be guided by the two goals\n\
1977    of preserving the free status of all derivatives of our free software and\n\
1978    of promoting the sharing and reuse of software generally.\n");
1979    }
1980    
1981    extern void warranty(environment *env)
1982    {
1983      printf("                          NO WARRANTY\n\
1984    \n\
1985      11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY\n\
1986    FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.  EXCEPT WHEN\n\
1987    OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES\n\
1988    PROVIDE THE PROGRAM \"AS IS\" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED\n\
1989    OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF\n\
1990    MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS\n\
1991    TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE\n\
1992    PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,\n\
1993    REPAIR OR CORRECTION.\n\
1994    \n\
1995      12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING\n\
1996    WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR\n\
1997    REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,\n\
1998    INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING\n\
1999    OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED\n\
2000    TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY\n\
2001    YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER\n\
2002    PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE\n\
2003    POSSIBILITY OF SUCH DAMAGES.\n");
2004    }
2005    
2006    /* "*" */
2007    extern void sx_2a(environment *env)
2008    {
2009      int a, b;
2010      float fa, fb;
2011    
2012      if(env->head==NULL || CDR(env->head)==NULL) {
2013        printerr("Too Few Arguments");
2014        env->err= 1;
2015        return;
2016      }
2017      
2018      if(CAR(env->head)->type==integer
2019         && CAR(CDR(env->head))->type==integer) {
2020        a= CAR(env->head)->content.i;
2021        toss(env); if(env->err) return;
2022        b= CAR(env->head)->content.i;
2023        toss(env); if(env->err) return;
2024        push_int(env, b*a);
2025    
2026        return;
2027      }
2028    
2029      if(CAR(env->head)->type==tfloat
2030         && CAR(CDR(env->head))->type==tfloat) {
2031        fa= CAR(env->head)->content.f;
2032        toss(env); if(env->err) return;
2033        fb= CAR(env->head)->content.f;
2034        toss(env); if(env->err) return;
2035        push_float(env, fb*fa);
2036        
2037        return;
2038      }
2039    
2040      if(CAR(env->head)->type==tfloat
2041         && CAR(CDR(env->head))->type==integer) {
2042        fa= CAR(env->head)->content.f;
2043        toss(env); if(env->err) return;
2044        b= CAR(env->head)->content.i;
2045        toss(env); if(env->err) return;
2046        push_float(env, b*fa);
2047        
2048        return;
2049      }
2050    
2051      if(CAR(env->head)->type==integer
2052         && CAR(CDR(env->head))->type==tfloat) {
2053        a= CAR(env->head)->content.i;
2054        toss(env); if(env->err) return;
2055        fb= CAR(env->head)->content.f;
2056        toss(env); if(env->err) return;
2057        push_float(env, fb*a);
2058    
2059        return;
2060      }
2061    
2062      printerr("Bad Argument Type");
2063      env->err= 2;
2064    }
2065    
2066    /* "/" */
2067    extern void sx_2f(environment *env)
2068    {
2069      int a, b;
2070      float fa, fb;
2071    
2072      if(env->head==NULL || CDR(env->head)==NULL) {
2073        printerr("Too Few Arguments");
2074        env->err= 1;
2075        return;
2076      }
2077      
2078      if(CAR(env->head)->type==integer
2079         && CAR(CDR(env->head))->type==integer) {
2080        a= CAR(env->head)->content.i;
2081        toss(env); if(env->err) return;
2082        b= CAR(env->head)->content.i;
2083        toss(env); if(env->err) return;
2084        push_float(env, b/a);
2085    
2086        return;
2087      }
2088    
2089      if(CAR(env->head)->type==tfloat
2090         && CAR(CDR(env->head))->type==tfloat) {
2091        fa= CAR(env->head)->content.f;
2092        toss(env); if(env->err) return;
2093        fb= CAR(env->head)->content.f;
2094        toss(env); if(env->err) return;
2095        push_float(env, fb/fa);
2096        
2097        return;
2098      }
2099    
2100      if(CAR(env->head)->type==tfloat
2101         && CAR(CDR(env->head))->type==integer) {
2102        fa= CAR(env->head)->content.f;
2103        toss(env); if(env->err) return;
2104        b= CAR(env->head)->content.i;
2105        toss(env); if(env->err) return;
2106        push_float(env, b/fa);
2107        
2108        return;
2109      }
2110    
2111      if(CAR(env->head)->type==integer
2112         && CAR(CDR(env->head))->type==tfloat) {
2113        a= CAR(env->head)->content.i;
2114        toss(env); if(env->err) return;
2115        fb= CAR(env->head)->content.f;
2116        toss(env); if(env->err) return;
2117        push_float(env, fb/a);
2118    
2119        return;
2120      }
2121    
2122      printerr("Bad Argument Type");
2123      env->err= 2;
2124    }
2125    
2126    /* "mod" */
2127    extern void mod(environment *env)
2128    {
2129      int a, b;
2130    
2131      if(env->head==NULL || CDR(env->head)==NULL) {
2132        printerr("Too Few Arguments");
2133        env->err= 1;
2134        return;
2135      }
2136      
2137      if(CAR(env->head)->type==integer
2138         && CAR(CDR(env->head))->type==integer) {
2139        a= CAR(env->head)->content.i;
2140        toss(env); if(env->err) return;
2141        b= CAR(env->head)->content.i;
2142        toss(env); if(env->err) return;
2143        push_int(env, b%a);
2144    
2145        return;
2146      }
2147    
2148      printerr("Bad Argument Type");
2149      env->err= 2;
2150    }
2151    
2152    /* "div" */
2153    extern void sx_646976(environment *env)
2154    {
2155      int a, b;
2156      
2157      if(env->head==NULL || CDR(env->head)==NULL) {
2158        printerr("Too Few Arguments");
2159        env->err= 1;
2160        return;
2161      }
2162    
2163      if(CAR(env->head)->type==integer
2164         && CAR(CDR(env->head))->type==integer) {
2165        a= CAR(env->head)->content.i;
2166        toss(env); if(env->err) return;
2167        b= CAR(env->head)->content.i;
2168        toss(env); if(env->err) return;
2169        push_int(env, (int)b/a);
2170    
2171        return;
2172      }
2173    
2174      printerr("Bad Argument Type");
2175      env->err= 2;
2176  }  }
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