--- stack/stack.c	2002/02/08 03:45:00	1.58
+++ stack/stack.c	2002/02/12 22:13:12	1.72
@@ -9,7 +9,7 @@
 /* strcmp, strcpy, strlen, strcat, strdup */
 #include <string.h>
 
-#define HASHTBLSIZE 65536
+#define HASHTBLSIZE 2048
 
 /* First, define some types. */
 
@@ -59,6 +59,7 @@
   hashtbl symbols;		/* Hash table of all variable bindings */
   int err;			/* Error flag */
   int non_eval_flag;
+  char *in_string;		/* Input pending to be read */
 } environment;
 
 /* A type for pointers to external functions */
@@ -70,6 +71,7 @@
 {
   int i;
 
+  env->in_string= NULL;
   env->err= 0;
   env->non_eval_flag= 0;
   for(i= 0; i<HASHTBLSIZE; i++)
@@ -154,23 +156,23 @@
 }
 
 /* Generic push function. */
-void push(stackitem** stack_head, stackitem* in_item)
+void push(environment *env, stackitem* in_item)
 {
-  in_item->next= *stack_head;
-  *stack_head= in_item;
+  in_item->next= env->head;
+  env->head= in_item;
 }
 
 /* Push a value onto the stack */
-void push_val(stackitem **stack_head, value *val)
+void push_val(environment *env, value *val)
 {
   stackitem *new_item= malloc(sizeof(stackitem));
   new_item->item= val;
   val->refcount++;
-  push(stack_head, new_item);
+  push(env, new_item);
 }
 
 /* Push an integer onto the stack. */
-void push_int(stackitem **stack_head, int in_val) 
+void push_int(environment *env, int in_val) 
 {
   value *new_value= malloc(sizeof(value));
   stackitem *new_item= malloc(sizeof(stackitem));
@@ -180,11 +182,11 @@
   new_value->type= integer;
   new_value->refcount=1;
 
-  push(stack_head, new_item);
+  push(env, new_item);
 }
 
 /* Copy a string onto the stack. */
-void push_cstring(stackitem **stack_head, const char *in_string)
+void push_cstring(environment *env, const char *in_string)
 {
   value *new_value= malloc(sizeof(value));
   stackitem *new_item= malloc(sizeof(stackitem));
@@ -195,7 +197,7 @@
   new_value->type= string;
   new_value->refcount=1;
 
-  push(stack_head, new_item);
+  push(env, new_item);
 }
 
 /* Mangle a symbol name to a valid C identifier name */
@@ -244,7 +246,7 @@
   new_value->type= string;
   new_value->refcount=1;
 
-  push_val(&(env->head), new_value);
+  push_val(env, new_value);
 }
 
 /* Push a symbol onto the stack. */
@@ -311,7 +313,7 @@
       new_fvalue->refcount= 1;
     }
   }
-  push(&(env->head), new_item);
+  push(env, new_item);
 }
 
 /* Print newline. */
@@ -347,9 +349,6 @@
   case list:
     push_sym(env, "list");
     break;
-  default:
-    push_sym(env, "unknown");
-    break;
   }
 }    
 
@@ -380,9 +379,6 @@
     }
     printf("]");
     break;
-  default:
-    printf("#<unknown %p>", (stack_head->item->content.ptr));
-    break;
   }
 }
 
@@ -481,11 +477,9 @@
   }
   toss(env);		/* toss the symbol */
   if(env->err) return;
-  push_val(&(env->head), val); /* Return its bound value */
+  push_val(env, val); /* Return its bound value */
 }
 
-void stack_read(environment*, char*);
-
 /* If the top element is a symbol, determine if it's bound to a
    function value, and if it is, toss the symbol and execute the
    function. */
@@ -494,7 +488,6 @@
   funcp in_func;
   value* temp_val;
   stackitem* iterator;
-  char* temp_string;
 
   if(env->head==NULL) {
     printerr("Too Few Arguments");
@@ -502,24 +495,24 @@
     return;
   }
 
+ eval_start:
+
   switch(env->head->item->type) {
     /* if it's a symbol */
   case symb:
     rcl(env);			/* get its contents */
     if(env->err) return;
     if(env->head->item->type!=symb){ /* don't recurse symbols */
-      eval(env);			/* evaluate the value */
-      return;
+      goto eval_start;
     }
-    break;
+    return;
 
     /* If it's a lone function value, run it */
   case func:
     in_func= (funcp)(env->head->item->content.ptr);
     toss(env); 
     if(env->err) return;
-    (*in_func)(env);
-    break;
+    return (*in_func)(env);
 
     /* If it's a list */
   case list:
@@ -528,39 +521,26 @@
     toss(env);
     if(env->err) return;
     iterator= (stackitem*)temp_val->content.ptr;
-    while(iterator!=NULL && iterator->item!=NULL) {
-      push_val(&(env->head), iterator->item);
+    while(iterator!=NULL) {
+      push_val(env, iterator->item);
       if(env->head->item->type==symb
 	&& strcmp(";", ((symbol*)(env->head->item->content.ptr))->id)==0) {
 	toss(env);
 	if(env->err) return;
+	if(iterator->next == NULL){
+	  free_val(temp_val);
+	  goto eval_start;
+	}
 	eval(env);
 	if(env->err) return;
       }
       iterator= iterator->next;
     }
     free_val(temp_val);
-    break;
-
-    /* If it's a string */
-  case string:
-    temp_val= env->head->item;
-    env->head->item->refcount++;
-    toss(env);
-    if(env->err) return;
-    temp_string= malloc(strlen((char*)temp_val->content.ptr)+5);
-    strcpy(temp_string, "[ ");
-    strcat(temp_string, (char*)temp_val->content.ptr);
-    strcat(temp_string, " ]");
-    stack_read(env, temp_string);
-    eval(env);
-    if(env->err) return;
-    free_val(temp_val);
-    free(temp_string);
-    break;
+    return;
 
-  case integer:
-    break;
+  default:
+    return;
   }
 }
 
@@ -630,89 +610,10 @@
   temp= malloc(sizeof(stackitem));
   temp->item= pack;
 
-  push(&(env->head), temp);
+  push(env, temp);
   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;
-
-  temp= malloc(inlength);
-  rest= malloc(inlength);
-
-  do {
-    /* If comment */
-    if((convert= sscanf(in_line, "#%[^\n\r]", rest))) {
-      free(temp); free(rest);
-      return;
-    }
-
-    /* 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(!env->non_eval_flag) {
-	  eval(env);		/* Evaluate top element */
-	  break;
-	}
-	
-	push_sym(env, ";");
-	break;
-      }
-
-      if(*temp==']') {
-	push_sym(env, "[");
-	pack(env);
-	if(env->non_eval_flag)
-	  env->non_eval_flag--;
-	break;
-      }
-
-      if(*temp=='[') {
-	push_sym(env, "[");
-	env->non_eval_flag++;
-	break;
-      }
-    }
-  } while(0);
-
-  free(temp);
-
-  if(convert<2) {
-    free(rest);
-    return;
-  }
-   
-  stack_read(env, rest);
-  
-  free(rest);
-}
-
 /* Relocate elements of the list on the stack. */
 extern void expand(environment *env)
 {
@@ -769,7 +670,7 @@
   result= (left==right);
   
   toss(env); toss(env);
-  push_int(&(env->head), result);
+  push_int(env, result);
 }
 
 /* Negates the top element on the stack. */
@@ -791,7 +692,7 @@
 
   val= env->head->item->content.val;
   toss(env);
-  push_int(&(env->head), !val);
+  push_int(env, !val);
 }
 
 /* Compares the two top elements on the stack and return 0 if they're the
@@ -897,25 +798,30 @@
 
 /* Returns the current error number to the stack */
 extern void errn(environment *env){
-  push_int(&(env->head), env->err);
+  push_int(env, env->err);
 }
 
+extern void read(environment*);
+
 int main()
 {
   environment myenv;
-  char in_string[100];
 
   init_env(&myenv);
 
-  printf("okidok\n ");
-
-  while(fgets(in_string, 100, stdin) != NULL) {
-    stack_read(&myenv, in_string);
+  while(1) {
+    if(myenv.in_string==NULL)
+      printstack(&myenv);
+    read(&myenv);
     if(myenv.err) {
       printf("(error %d) ", myenv.err);
       myenv.err=0;
+    } else if(myenv.head!=NULL
+	      && myenv.head->item->type==symb
+	      && ((symbol*)(myenv.head->item->content.ptr))->id[0]==';') {
+      toss(&myenv); 		/* No error check in main */
+      eval(&myenv);
     }
-    printf("okidok\n ");
   }
   quit(&myenv);
   return EXIT_FAILURE;
@@ -947,7 +853,7 @@
     strcpy(new_string, b_val->content.ptr);
     strcat(new_string, a_val->content.ptr);
     free_val(a_val); free_val(b_val);
-    push_cstring(&(env->head), new_string);
+    push_cstring(env, new_string);
     free(new_string);
     return;
   }
@@ -961,10 +867,72 @@
   a=env->head->item->content.val;
   toss(env);
   if(env->err) return;
-  b=env->head->item->content.val;
+  if(env->head->item->refcount == 1)
+    env->head->item->content.val += a;
+  else {
+    b=env->head->item->content.val;
+    toss(env);
+    if(env->err) return;
+    push_int(env, a+b);
+  }
+}
+
+/* - */
+extern void sx_2d(environment *env) {
+  int a, b;
+
+  if((env->head)==NULL || env->head->next==NULL) {
+    printerr("Too Few Arguments");
+    env->err=1;
+    return;
+  }
+  
+  if(env->head->item->type!=integer
+     || env->head->next->item->type!=integer) {
+    printerr("Bad Argument Type");
+    env->err=2;
+    return;
+  }
+  a=env->head->item->content.val;
+  toss(env);
+  if(env->err) return;
+  if(env->head->item->refcount == 1)
+    env->head->item->content.val -= a;
+  else {
+    b=env->head->item->content.val;
+    toss(env);
+    if(env->err) return;
+    push_int(env, b-a);
+  }
+}
+
+/* > */
+extern void sx_3e(environment *env) {
+  int a, b;
+
+  if((env->head)==NULL || env->head->next==NULL) {
+    printerr("Too Few Arguments");
+    env->err=1;
+    return;
+  }
+  
+  if(env->head->item->type!=integer
+     || env->head->next->item->type!=integer) {
+    printerr("Bad Argument Type");
+    env->err=2;
+    return;
+  }
+  a=env->head->item->content.val;
   toss(env);
   if(env->err) return;
-  push_int(&(env->head), a+b);
+  if(env->head->item->refcount == 1)
+    env->head->item->content.val = (env->head->item->content.val > a);
+  else {
+    b=env->head->item->content.val;
+    toss(env);
+    if(env->err) return;
+    push_int(env, b>a);
+  }
 }
 
 /* Return copy of a value */
@@ -1019,10 +987,10 @@
     env->err=1;
     return;
   }
-  push_val(&(env->head), copy_val(env->head->item));
+  push_val(env, copy_val(env->head->item));
 }
 
-/* If-Then */
+/* "if", If-Then */
 extern void sx_6966(environment *env) {
 
   int truth;
@@ -1093,6 +1061,7 @@
 extern void sx_7768696c65(environment *env) {
 
   int truth;
+  value *loop, *test;
 
   if((env->head)==NULL || env->head->next==NULL) {
     printerr("Too Few Arguments");
@@ -1100,10 +1069,17 @@
     return;
   }
 
+  loop= env->head->item;
+  loop->refcount++;
+  toss(env); if(env->err) return;
+
+  test= env->head->item;
+  test->refcount++;
+  toss(env); if(env->err) return;
+
   do {
-    swap(env); if(env->err) return;
-    dup(env); if(env->err) return;
-    eval(env); if(env->err) return;
+    push_val(env, test);
+    eval(env);
     
     if(env->head->item->type != integer) {
       printerr("Bad Argument Type");
@@ -1112,17 +1088,158 @@
     }
     
     truth= env->head->item->content.val;
-    
     toss(env); if(env->err) return;
-    swap(env); if(env->err) return;
     
     if(truth) {
-      dup(env);
+      push_val(env, loop);
       eval(env);
     } else {
       toss(env);
-      toss(env);
     }
   
   } while(truth);
+
+  free_val(test);
+  free_val(loop);
+}
+
+/* For-loop */
+extern void sx_666f72(environment *env) {
+  
+  value *loop, *foo;
+  stackitem *iterator;
+  
+  if((env->head)==NULL || env->head->next==NULL) {
+    printerr("Too Few Arguments");
+    env->err=1;
+    return;
+  }
+
+  if(env->head->next->item->type != list) {
+    printerr("Bad Argument Type");
+    env->err=2;
+    return;
+  }
+
+  loop= env->head->item;
+  loop->refcount++;
+  toss(env); if(env->err) return;
+
+  foo= env->head->item;
+  foo->refcount++;
+  toss(env); if(env->err) return;
+
+  iterator= foo->content.ptr;
+
+  while(iterator!=NULL) {
+    push_val(env, iterator->item);
+    push_val(env, loop);
+    eval(env); if(env->err) return;
+    iterator= iterator->next;
+  }
+
+  free_val(loop);
+  free_val(foo);
+}
+
+/* 'to' */
+extern void to(environment *env) {
+  int i, start, ending;
+  
+  if((env->head)==NULL || env->head->next==NULL) {
+    printerr("Too Few Arguments");
+    env->err=1;
+    return;
+  }
+
+  if(env->head->item->type!=integer 
+     || env->head->next->item->type!=integer) {
+    printerr("Bad Argument Type");
+    env->err=2;
+    return;
+  }
+
+  ending= env->head->item->content.val;
+  toss(env); if(env->err) return;
+  start= env->head->item->content.val;
+  toss(env); if(env->err) return;
+
+  push_sym(env, "[");
+
+  if(ending>=start) {
+    for(i= start; i<=ending; i++)
+      push_int(env, i);
+  } else {
+    for(i= start; i>=ending; i--)
+      push_int(env, i);
+  }
+
+  push_sym(env, "[");
+  pack(env); if(env->err) return;
+}
+
+/* Read a string */
+extern void readline(environment *env) {
+  char in_string[101];
+
+  fgets(in_string, 100, stdin);
+  push_cstring(env, in_string);
+}
+
+/* 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]";
+
+  int itemp;
+  static int depth= 0;
+  char *rest, *match;
+  size_t inlength;
+
+  if(env->in_string==NULL) {
+    readline(env); if(env->err) return;
+    
+    env->in_string= malloc(strlen(env->head->item->content.ptr)+1);
+    strcpy(env->in_string, env->head->item->content.ptr);
+    toss(env); if(env->err) return;
+  }
+  
+  inlength= strlen(env->in_string)+1;
+  match= malloc(inlength);
+  rest= malloc(inlength);
+
+  if(sscanf(env->in_string, blankform, rest)) {
+    ; 
+  } else if(sscanf(env->in_string, intform, &itemp, rest) > 0) {
+    push_int(env, itemp);
+  } else if(sscanf(env->in_string, strform, match, rest) > 0) {
+    push_cstring(env, match);
+  } else if(sscanf(env->in_string, symbform, match, rest) > 0) {
+    push_sym(env, match);
+  } else if(sscanf(env->in_string, ebrackform, rest) > 0) {
+    push_sym(env, "[");
+    pack(env); if(env->err) return;
+    if(depth!=0) depth--;
+  } else if(sscanf(env->in_string, semicform, rest) > 0) {
+    push_sym(env, ";");
+  } else if(sscanf(env->in_string, bbrackform, rest) > 0) {
+    push_sym(env, "[");
+    depth++;
+  } else {
+    free(rest);
+    rest= NULL;
+  }
+      
+  free(env->in_string);
+  free(match);
+
+  env->in_string= rest;
+
+  if(depth)
+    return read(env);
 }