--- stack/stack.c	2002/02/06 00:30:14	1.35
+++ stack/stack.c	2002/02/06 11:15:05	1.38
@@ -218,6 +218,7 @@
     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 */
@@ -240,7 +241,7 @@
   stackitem *temp= env->head;
 
   if((env->head)==NULL) {
-    printerr("Stack empty");
+    printerr("Too Few Arguments");
     env->err=1;
     return;
   }
@@ -256,6 +257,39 @@
   printf("\n");
 }
 
+/* Gets the type of a value */
+extern void type(environment *env){
+  int typenum;
+
+  if((env->head)==NULL) {
+    printerr("Too Few Arguments");
+    env->err=1;
+    return;
+  }
+  typenum=env->head->item->type;
+  toss(env);
+  switch(typenum){
+  case integer:
+    push_sym(env, "integer");
+    break;
+  case string:
+    push_sym(env, "string");
+    break;
+  case symb:
+    push_sym(env, "symbol");
+    break;
+  case func:
+    push_sym(env, "function");
+    break;
+  case list:
+    push_sym(env, "list");
+    break;
+  default:
+    push_sym(env, "unknown");
+    break;
+  }
+}    
+
 /* Prints the top element of the stack. */
 void print_h(stackitem *stack_head)
 {
@@ -273,17 +307,25 @@
     printf("#<function %p>", (funcp)(stack_head->item->content.ptr));
     break;
   case list:
-    printf("#<list %p>", (funcp)(stack_head->item->content.ptr));
+    /* A list is just a stack, so make stack_head point to it */
+    stack_head=(stackitem *)(stack_head->item->content.ptr);
+    printf("[ ");
+    while(stack_head != NULL) {
+      print_h(stack_head);
+      printf(" ");
+      stack_head=stack_head->next;
+    }
+    printf("] ");
     break;
   default:
-    printf("#<unknown %p>", (funcp)(stack_head->item->content.ptr));
+    printf("#<unknown %p>", (stack_head->item->content.ptr));
     break;
   }
 }
 
 extern void print_(environment *env) {
   if(env->head==NULL) {
-    printerr("Stack empty");
+    printerr("Too Few Arguments");
     env->err=1;
     return;
   }
@@ -314,8 +356,6 @@
 extern void printstack(environment *env)
 {
   if(env->head == NULL) {
-    printerr("Stack empty");
-    env->err=1;
     return;
   }
   print_st(env->head, 1);
@@ -328,13 +368,13 @@
   stackitem *temp= env->head;
   
   if((env->head)==NULL) {
-    printerr("Stack empty");
+    printerr("Too Few Arguments");
     env->err=1;
     return;
   }
 
   if(env->head->next==NULL) {
-    printerr("Not enough arguments");
+    printerr("Too Few Arguments");
     env->err=1;
     return;
   }
@@ -360,21 +400,21 @@
   value *val;
 
   if(env->head == NULL) {
-    printerr("Stack empty");
+    printerr("Too Few Arguments");
     env->err=1;
     return;
   }
 
   if(env->head->item->type!=symb) {
-    printerr("Not a symbol");
-    env->err=1;
+    printerr("Bad Argument Type");
+    env->err=2;
     return;
   }
 
   val=((symbol *)(env->head->item->content.ptr))->val;
   if(val == NULL){
-    printerr("Unbound variable");
-    env->err=1;
+    printerr("Unbound Variable");
+    env->err=3;
     return;
   }
   toss(env);		/* toss the symbol */
@@ -389,7 +429,7 @@
 {
   funcp in_func;
   if(env->head==NULL) {
-    printerr("Stack empty");
+    printerr("Too Few Arguments");
     env->err=1;
     return;
   }
@@ -457,7 +497,7 @@
 }
 
 /* Parse input. */
-int stack_read(environment *env, char *in_line) 
+void stack_read(environment *env, char *in_line) 
 {
   char *temp, *rest;
   int itemp;
@@ -518,18 +558,16 @@
     }
   } while(0);
 
-
   free(temp);
 
   if(convert<2) {
     free(rest);
-    return 0;
+    return;
   }
    
   stack_read(env, rest);
   
   free(rest);
-  return 1;
 }
 
 /* Relocate elements of the list on the stack. */
@@ -538,11 +576,16 @@
   stackitem *temp, *new_head;
 
   /* Is top element a list? */
-  if(env->head==NULL || env->head->item->type!=list) {
-    printerr("Stack empty or not a list");
+  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;
+  }
 
   /* The first list element is the new stack head */
   new_head= temp= env->head->item->content.ptr;
@@ -567,7 +610,7 @@
   int result;
 
   if((env->head)==NULL || env->head->next==NULL) {
-    printerr("Not enough elements to compare");
+    printerr("Too Few Arguments");
     env->err=1;
     return;
   }
@@ -586,12 +629,18 @@
 {
   int val;
 
-  if((env->head)==NULL || env->head->item->type!=integer) {
-    printerr("Stack empty or element is not a integer");
+  if((env->head)==NULL) {
+    printerr("Too Few Arguments");
     env->err=1;
     return;
   }
 
+  if(env->head->item->type!=integer) {
+    printerr("Bad Argument Type");
+    env->err=2;
+    return;
+  }
+
   val= env->head->item->content.val;
   toss(env);
   push_int(&(env->head), !val);
@@ -611,13 +660,18 @@
   symbol *sym;
 
   /* Needs two values on the stack, the top one must be a symbol */
-  if(env->head==NULL || env->head->next==NULL 
-     || env->head->item->type!=symb) {
-    printerr("Define what?");
+  if(env->head==NULL || env->head->next==NULL) {
+    printerr("Too Few Arguments");
     env->err=1;
     return;
   }
 
+  if(env->head->item->type!=symb) {
+    printerr("Bad Argument Type");
+    env->err=2;
+    return;
+  }
+
   /* long names are a pain */
   sym=env->head->item->content.ptr;
 
@@ -667,8 +721,15 @@
   stackitem *stack_head= env->head;
   symbol **hash_entry, *temp;
 
-  if(stack_head==NULL || stack_head->item->type!=symb) {
-    printerr("Stack empty or not a symbol");
+  if(stack_head==NULL) {
+    printerr("Too Few Arguments");
+    env->err=1;
+    return;
+  }
+  
+  if(stack_head->item->type!=symb) {
+    printerr("Bad Argument Type");
+    env->err=2;
     return;
   }
 
@@ -684,7 +745,12 @@
   }
   free(temp->id);
   free(temp);
-} 
+}
+
+/* Returns the current error number to the stack */
+extern void errn(environment *env){
+  push_int(&(env->head), env->err);
+}
 
 int main()
 {