--- stack/stack.c	2002/02/12 22:13:12	1.72
+++ stack/stack.c	2002/02/14 19:49:48	1.82
@@ -58,8 +58,9 @@
   stackitem *head;		/* Head of the stack */
   hashtbl symbols;		/* Hash table of all variable bindings */
   int err;			/* Error flag */
-  int non_eval_flag;
   char *in_string;		/* Input pending to be read */
+  char *free_string;		/* Free this string when all input is
+                                   read from in_string */
 } environment;
 
 /* A type for pointers to external functions */
@@ -73,7 +74,6 @@
 
   env->in_string= NULL;
   env->err= 0;
-  env->non_eval_flag= 0;
   for(i= 0; i<HASHTBLSIZE; i++)
     env->symbols[i]= NULL;
 }
@@ -100,13 +100,18 @@
 	free(item);		/* free the stackitem */
 	item=temp;		/* go to next stackitem */
       }
-      free(val);		/* Free the actual list value */
       break;
     case integer:
     case func:
+      break;
     case symb:
+      free(((symbol*)(val->content.ptr))->id);
+      if(((symbol*)(val->content.ptr))->val!=NULL)
+	free_val(((symbol*)(val->content.ptr))->val);
+      free(val->content.ptr);
       break;
     }
+    free(val);		/* Free the actual list value */
   }
 }
 
@@ -155,49 +160,39 @@
   }
 }
 
-/* Generic push function. */
-void push(environment *env, stackitem* in_item)
-{
-  in_item->next= env->head;
-  env->head= in_item;
-}
-
 /* Push a value onto the stack */
 void push_val(environment *env, value *val)
 {
   stackitem *new_item= malloc(sizeof(stackitem));
   new_item->item= val;
   val->refcount++;
-  push(env, new_item);
+  new_item->next= env->head;
+  env->head= new_item;
 }
 
 /* Push an integer onto the stack. */
 void push_int(environment *env, int in_val) 
 {
   value *new_value= malloc(sizeof(value));
-  stackitem *new_item= malloc(sizeof(stackitem));
-  new_item->item= new_value;
   
   new_value->content.val= in_val;
   new_value->type= integer;
-  new_value->refcount=1;
+  new_value->refcount= 1;
 
-  push(env, new_item);
+  push_val(env, new_value);
 }
 
 /* Copy a string onto the stack. */
 void push_cstring(environment *env, const char *in_string)
 {
   value *new_value= malloc(sizeof(value));
-  stackitem *new_item= malloc(sizeof(stackitem));
-  new_item->item=new_value;
 
   new_value->content.ptr= malloc(strlen(in_string)+1);
   strcpy(new_value->content.ptr, in_string);
   new_value->type= string;
-  new_value->refcount=1;
+  new_value->refcount= 1;
 
-  push(env, new_item);
+  push_val(env, new_value);
 }
 
 /* Mangle a symbol name to a valid C identifier name */
@@ -221,7 +216,6 @@
 }
 
 extern void mangle(environment *env){
-  value *new_value;
   char *new_string;
 
   if((env->head)==NULL) {
@@ -241,19 +235,12 @@
   toss(env);
   if(env->err) return;
 
-  new_value= malloc(sizeof(value));
-  new_value->content.ptr= new_string;
-  new_value->type= string;
-  new_value->refcount=1;
-
-  push_val(env, new_value);
+  push_cstring(env, new_string);
 }
 
 /* Push a symbol onto the stack. */
 void push_sym(environment *env, const char *in_string)
 {
-  stackitem *new_item;		/* The new stack item */
-  /* ...which will contain... */
   value *new_value;		/* A new symbol value */
   /* ...which might point to... */
   symbol **new_symbol;		/* (if needed) A new actual symbol */
@@ -266,10 +253,7 @@
   const char *dlerr;		/* Dynamic linker error */
   char *mangled;		/* Mangled function name */
 
-  /* Create a new stack item containing a new value */
-  new_item= malloc(sizeof(stackitem));
   new_value= malloc(sizeof(value));
-  new_item->item=new_value;
 
   /* The new value is a symbol */
   new_value->type= symb;
@@ -313,7 +297,7 @@
       new_fvalue->refcount= 1;
     }
   }
-  push(env, new_item);
+  push_val(env, new_value);
 }
 
 /* Print newline. */
@@ -353,14 +337,17 @@
 }    
 
 /* Prints the top element of the stack. */
-void print_h(stackitem *stack_head)
+void print_h(stackitem *stack_head, int noquote)
 {
   switch(stack_head->item->type) {
   case integer:
     printf("%d", stack_head->item->content.val);
     break;
   case string:
-    printf("%s", (char*)stack_head->item->content.ptr);
+    if(noquote)
+      printf("%s", (char*)stack_head->item->content.ptr);
+    else
+      printf("\"%s\"", (char*)stack_head->item->content.ptr);
     break;
   case symb:
     printf("%s", ((symbol *)(stack_head->item->content.ptr))->id);
@@ -373,7 +360,7 @@
     stack_head=(stackitem *)(stack_head->item->content.ptr);
     printf("[ ");
     while(stack_head != NULL) {
-      print_h(stack_head);
+      print_h(stack_head, noquote);
       printf(" ");
       stack_head=stack_head->next;
     }
@@ -388,7 +375,8 @@
     env->err=1;
     return;
   }
-  print_h(env->head);
+  print_h(env->head, 0);
+  nl();
 }
 
 /* Prints the top element of the stack and then discards it. */
@@ -399,13 +387,30 @@
   toss(env);
 }
 
+extern void princ_(environment *env) {
+  if(env->head==NULL) {
+    printerr("Too Few Arguments");
+    env->err=1;
+    return;
+  }
+  print_h(env->head, 1);
+}
+
+/* Prints the top element of the stack and then discards it. */
+extern void princ(environment *env)
+{
+  princ_(env);
+  if(env->err) return;
+  toss(env);
+}
+
 /* Only to be called by function printstack. */
 void print_st(stackitem *stack_head, long counter)
 { 
   if(stack_head->next != NULL)
     print_st(stack_head->next, counter+1);
   printf("%ld: ", counter);
-  print_h(stack_head);
+  print_h(stack_head, 0);
   nl();
 }
 
@@ -413,10 +418,10 @@
 extern void printstack(environment *env)
 {
   if(env->head == NULL) {
+    printf("Stack Empty\n");
     return;
   }
   print_st(env->head, 1);
-  nl();
 }
 
 /* Swap the two top elements on the stack. */
@@ -489,14 +494,14 @@
   value* temp_val;
   stackitem* iterator;
 
+ eval_start:
+
   if(env->head==NULL) {
     printerr("Too Few Arguments");
     env->err=1;
     return;
   }
 
- eval_start:
-
   switch(env->head->item->type) {
     /* if it's a symbol */
   case symb:
@@ -574,22 +579,21 @@
 /* Make a list. */
 extern void pack(environment *env)
 {
-  void* delimiter;
   stackitem *iterator, *temp;
   value *pack;
 
-  delimiter= env->head->item->content.ptr; /* Get delimiter */
-  toss(env);
-
   iterator= env->head;
 
-  if(iterator==NULL || iterator->item->content.ptr==delimiter) {
+  if(iterator==NULL
+     || (iterator->item->type==symb
+     && ((symbol*)(iterator->item->content.ptr))->id[0]=='[')) {
     temp= NULL;
     toss(env);
   } else {
     /* Search for first delimiter */
     while(iterator->next!=NULL
-	  && iterator->next->item->content.ptr!=delimiter)
+	  && (iterator->next->item->type!=symb
+	  || ((symbol*)(iterator->next->item->content.ptr))->id[0]!='['))
       iterator= iterator->next;
     
     /* Extract list */
@@ -607,10 +611,7 @@
   pack->content.ptr= temp;
   pack->refcount= 1;
 
-  temp= malloc(sizeof(stackitem));
-  temp->item= pack;
-
-  push(env, temp);
+  push_val(env, pack);
   rev(env);
 }
 
@@ -735,9 +736,22 @@
   toss(env); toss(env);
 } 
 
+extern void clear(environment *);
+void forget_sym(symbol **);
+
 /* Quit stack. */
 extern void quit(environment *env)
 {
+  long i;
+
+  clear(env);
+  if (env->err) return;
+  for(i= 0; i<HASHTBLSIZE; i++) {
+    while(env->symbols[i]!= NULL) {
+      forget_sym(&(env->symbols[i]));
+    }
+    env->symbols[i]= NULL;
+  }
   exit(EXIT_SUCCESS);
 }
 
@@ -763,12 +777,25 @@
   }
 }
 
+/* Internal forget function */
+void forget_sym(symbol **hash_entry) {
+  symbol *temp;
+
+  temp= *hash_entry;
+  *hash_entry= (*hash_entry)->next;
+  
+  if(temp->val!=NULL) {
+    free_val(temp->val);
+  }
+  free(temp->id);
+  free(temp);
+}
+
 /* Forgets a symbol (remove it from the hash table) */
 extern void forget(environment *env)
 {
   char* sym_id;
   stackitem *stack_head= env->head;
-  symbol **hash_entry, *temp;
 
   if(stack_head==NULL) {
     printerr("Too Few Arguments");
@@ -785,15 +812,7 @@
   sym_id= ((symbol*)(stack_head->item->content.ptr))->id;
   toss(env);
 
-  hash_entry= 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);
+  return forget_sym(hash(env->symbols, sym_id));
 }
 
 /* Returns the current error number to the stack */
@@ -810,8 +829,11 @@
   init_env(&myenv);
 
   while(1) {
-    if(myenv.in_string==NULL)
+    if(myenv.in_string==NULL) {
+      nl();
       printstack(&myenv);
+      printf("> ");
+    }
     read(&myenv);
     if(myenv.err) {
       printf("(error %d) ", myenv.err);
@@ -1145,6 +1167,8 @@
 /* 'to' */
 extern void to(environment *env) {
   int i, start, ending;
+  stackitem *temp_head;
+  value *temp_val;
   
   if((env->head)==NULL || env->head->next==NULL) {
     printerr("Too Few Arguments");
@@ -1164,18 +1188,23 @@
   start= env->head->item->content.val;
   toss(env); if(env->err) return;
 
-  push_sym(env, "[");
+  temp_head= env->head;
+  env->head= NULL;
 
   if(ending>=start) {
-    for(i= start; i<=ending; i++)
+    for(i= ending; i>=start; i--)
       push_int(env, i);
   } else {
-    for(i= start; i>=ending; i--)
+    for(i= ending; i<=start; i++)
       push_int(env, i);
   }
 
-  push_sym(env, "[");
-  pack(env); if(env->err) return;
+  temp_val= malloc(sizeof(value));
+  temp_val->content.ptr= env->head;
+  temp_val->refcount= 1;
+  temp_val->type= list;
+  env->head= temp_head;
+  push_val(env, temp_val);
 }
 
 /* Read a string */
@@ -1188,23 +1217,27 @@
 
 /* Read a value and place on stack */
 extern void read(environment *env) {
-  const char symbform[]= "%[a-zA-Z0-9!$%*+./:<=>?@^_~-]%[\001-\377]";
-  const char strform[]= "\"%[^\"]\"%[\001-\377]";
-  const char intform[]= "%i%[\001-\377]";
-  const char blankform[]= "%*[ \t]%[\001-\377]";
-  const char ebrackform[]= "%*1[]]%[\001-\377]";
-  const char semicform[]= "%*1[;]%[\001-\377]";
-  const char bbrackform[]= "%*1[[]%[\001-\377]";
+  const char symbform[]= "%[a-zA-Z0-9!$%*+./:<=>?@^_~-]%n";
+  const char strform[]= "\"%[^\"]\"%n";
+  const char intform[]= "%i%n";
+  const char blankform[]= "%*[ \t]%n";
+  const char ebrackform[]= "%*1[]]%n";
+  const char semicform[]= "%*1[;]%n";
+  const char bbrackform[]= "%*1[[]%n";
 
-  int itemp;
+  int itemp, readlength= -1;
   static int depth= 0;
   char *rest, *match;
   size_t inlength;
 
   if(env->in_string==NULL) {
+    if(depth > 0) {
+      printf("]> ");
+    }
     readline(env); if(env->err) return;
     
     env->in_string= malloc(strlen(env->head->item->content.ptr)+1);
+    env->free_string= env->in_string; /* Save the original pointer */
     strcpy(env->in_string, env->head->item->content.ptr);
     toss(env); if(env->err) return;
   }
@@ -1213,32 +1246,37 @@
   match= malloc(inlength);
   rest= malloc(inlength);
 
-  if(sscanf(env->in_string, blankform, rest)) {
+  if(sscanf(env->in_string, blankform, &readlength)!=EOF
+     && readlength != -1) {
     ; 
-  } else if(sscanf(env->in_string, intform, &itemp, rest) > 0) {
+  } else if(sscanf(env->in_string, intform, &itemp, &readlength) != EOF
+	    && readlength != -1) {
     push_int(env, itemp);
-  } else if(sscanf(env->in_string, strform, match, rest) > 0) {
+  } else if(sscanf(env->in_string, strform, match, &readlength) != EOF
+	    && readlength != -1) {
     push_cstring(env, match);
-  } else if(sscanf(env->in_string, symbform, match, rest) > 0) {
+  } else if(sscanf(env->in_string, symbform, match, &readlength) != EOF
+	    && readlength != -1) {
     push_sym(env, match);
-  } else if(sscanf(env->in_string, ebrackform, rest) > 0) {
-    push_sym(env, "[");
+  } else if(sscanf(env->in_string, ebrackform, &readlength) != EOF
+	    && readlength != -1) {
     pack(env); if(env->err) return;
-    if(depth!=0) depth--;
-  } else if(sscanf(env->in_string, semicform, rest) > 0) {
+    if(depth != 0) depth--;
+  } else if(sscanf(env->in_string, semicform, &readlength) != EOF
+	    && readlength != -1) {
     push_sym(env, ";");
-  } else if(sscanf(env->in_string, bbrackform, rest) > 0) {
+  } else if(sscanf(env->in_string, bbrackform, &readlength) != EOF
+	    && readlength != -1) {
     push_sym(env, "[");
     depth++;
   } else {
-    free(rest);
-    rest= NULL;
+    free(env->free_string);
+    env->in_string = env->free_string = NULL;
+    free(match);
+  }
+  if ( env->in_string != NULL) {
+    env->in_string += readlength;
   }
-      
-  free(env->in_string);
-  free(match);
-
-  env->in_string= rest;
 
   if(depth)
     return read(env);