--- stack/stack.c	2002/03/09 09:58:31	1.94
+++ stack/stack.c	2002/03/10 07:55:13	1.96
@@ -48,7 +48,7 @@
 {
   int i;
 
-  env->gc_limit= 20;
+  env->gc_limit= 200;
   env->gc_count= 0;
   env->gc_ref= NULL;
   env->gc_protect= NULL;
@@ -63,7 +63,8 @@
   env->interactive= 1;
 }
 
-void printerr(const char* in_string) {
+void printerr(const char* in_string)
+{
   fprintf(stderr, "Err: %s\n", in_string);
 }
 
@@ -81,7 +82,7 @@
   env->head= env->head->next;	/* Remove the top stack item */
   free(temp);			/* Free the old top stack item */
 
-  gc_init(env);
+  env->gc_limit--;
 }
 
 /* Returns a pointer to a pointer to an element in the hash table. */
@@ -113,7 +114,9 @@
   }
 }
 
-value* new_val(environment *env) {
+/* Create new value */
+value* new_val(environment *env)
+{
   value *nval= malloc(sizeof(value));
   stackitem *nitem= malloc(sizeof(stackitem));
 
@@ -125,14 +128,13 @@
 
   env->gc_count++;
 
-  protect(env, nval);
-  gc_init(env);
-  unprotect(env);
-
   return nval;
 }
 
-void gc_mark(value *val) {
+/* Mark values recursively. 
+   Marked values are not collected by the GC. */
+inline void gc_mark(value *val)
+{
   stackitem *iterator;
 
   if(val==NULL || val->gc_garb==0)
@@ -150,14 +152,21 @@
   }
 }
 
-extern void gc_init(environment *env) {
+inline void gc_maybe(environment *env)
+{
+  if(env->gc_count < env->gc_limit)
+    return;
+  else
+    return gc_init(env);
+}
+
+/* Start GC */
+extern void gc_init(environment *env)
+{
   stackitem *new_head= NULL, *titem, *iterator;
   symbol *tsymb;
   int i;
 
-  if(env->gc_count < env->gc_limit)
-    return;
-
   /* Garb by default */
   iterator= env->gc_ref;
   while(iterator!=NULL) {
@@ -172,7 +181,7 @@
     iterator= iterator->next;
   }
 
-  /* Mark values in stack */
+  /* Mark values on stack */
   iterator= env->head;
   while(iterator!=NULL) {
     gc_mark(iterator->item);
@@ -190,13 +199,11 @@
 
   env->gc_count= 0;
 
-  /* Sweep */
-  while(env->gc_ref!=NULL) {
+  while(env->gc_ref!=NULL) {	/* Sweep unused values */
 
     if(env->gc_ref->item->gc_garb) {
 
-      /* Remove content */
-      switch(env->gc_ref->item->type) {	
+      switch(env->gc_ref->item->type) {	/* Remove content */
       case string:
 	free(env->gc_ref->item->content.ptr);
 	break;
@@ -214,7 +221,7 @@
       titem= env->gc_ref->next;
       free(env->gc_ref);	/* Remove value */
       env->gc_ref= titem;
-    } else {			/* Save */
+    } else {			/* Keep values */
       titem= env->gc_ref->next;
       env->gc_ref->next= new_head;
       new_head= env->gc_ref;
@@ -227,6 +234,7 @@
   env->gc_ref= new_head;
 }
 
+/* Protect values from GC */
 void protect(environment *env, value *val)
 {
   stackitem *new_item= malloc(sizeof(stackitem));
@@ -235,6 +243,7 @@
   env->gc_protect= new_item;
 }
 
+/* Unprotect values from GC */
 void unprotect(environment *env)
 {
   stackitem *temp= env->gc_protect;
@@ -251,7 +260,7 @@
   env->head= new_item;
 }
 
-/* Push an integer onto the stack. */
+/* Push an integer onto the stack */
 void push_int(environment *env, int in_val) 
 {
   value *new_value= new_val(env);
@@ -262,6 +271,7 @@
   push_val(env, new_value);
 }
 
+/* Push a floating point number onto the stack */
 void push_float(environment *env, float in_val)
 {
   value *new_value= new_val(env);
@@ -285,7 +295,8 @@
 }
 
 /* Mangle a symbol name to a valid C identifier name */
-char *mangle_str(const char *old_string){
+char *mangle_str(const char *old_string)
+{
   char validchars[]= "0123456789abcdef";
   char *new_string, *current;
 
@@ -303,7 +314,8 @@
   return new_string;		/* The caller must free() it */
 }
 
-extern void mangle(environment *env){
+extern void mangle(environment *env)
+{
   char *new_string;
 
   if((env->head)==NULL) {
@@ -372,19 +384,23 @@
 
     mangled= mangle_str(in_string); /* mangle the name */
     funcptr= dlsym(handle, mangled); /* and try to find it */
-    free(mangled);
+
     dlerr= dlerror();
     if(dlerr != NULL) {		/* If no function was found */
       funcptr= dlsym(handle, in_string); /* Get function pointer */
       dlerr= dlerror();
     }
+
     if(dlerr==NULL) {		/* If a function was found */
       new_fvalue->type= func;	/* The new value is a function pointer */
       new_fvalue->content.ptr= funcptr; /* Store function pointer */
       (*new_symbol)->val= new_fvalue; /* Bind the symbol to the new
                                          function value */
     }
+
+    free(mangled);
   }
+
   push_val(env, new_value);
   unprotect(env); unprotect(env);
 }
@@ -396,7 +412,8 @@
 }
 
 /* Gets the type of a value */
-extern void type(environment *env){
+extern void type(environment *env)
+{
   int typenum;
 
   if((env->head)==NULL) {
@@ -464,7 +481,8 @@
   }
 }
 
-extern void print_(environment *env) {
+extern void print_(environment *env)
+{
   if(env->head==NULL) {
     printerr("Too Few Arguments");
     env->err=1;
@@ -482,7 +500,8 @@
   toss(env);
 }
 
-extern void princ_(environment *env) {
+extern void princ_(environment *env)
+{
   if(env->head==NULL) {
     printerr("Too Few Arguments");
     env->err=1;
@@ -516,6 +535,7 @@
     printf("Stack Empty\n");
     return;
   }
+
   print_st(env->head, 1);
 }
 
@@ -593,6 +613,8 @@
 
  eval_start:
 
+  gc_maybe(env);
+
   if(env->head==NULL) {
     printerr("Too Few Arguments");
     env->err=1;
@@ -649,7 +671,8 @@
 }
 
 /* Reverse (flip) a list */
-extern void rev(environment *env){
+extern void rev(environment *env)
+{
   stackitem *old_head, *new_head, *item;
 
   if((env->head)==NULL) {
@@ -835,7 +858,7 @@
 /* Quit stack. */
 extern void quit(environment *env)
 {
-  long i;
+  int i;
 
   clear(env);
 
@@ -848,7 +871,7 @@
   }
 
   env->gc_limit= 0;
-  gc_init(env);
+  gc_maybe(env);
 
   if(env->free_string!=NULL)
     free(env->free_string);
@@ -881,7 +904,8 @@
 }
 
 /* Internal forget function */
-void forget_sym(symbol **hash_entry) {
+void forget_sym(symbol **hash_entry)
+{
   symbol *temp;
 
   temp= *hash_entry;
@@ -916,7 +940,8 @@
 }
 
 /* Returns the current error number to the stack */
-extern void errn(environment *env){
+extern void errn(environment *env)
+{
   push_int(env, env->err);
 }
 
@@ -957,7 +982,7 @@
   }
 
   if(myenv.interactive) {
-    printf("Stack version $Revision: 1.94 $\n\
+    printf("Stack version $Revision: 1.96 $\n\
 Copyright (C) 2002  Mats Alritzson and Teddy Hogeborn\n\
 Stack comes with ABSOLUTELY NO WARRANTY; for details type `warranty;'.\n\
 This is free software, and you are welcome to redistribute it\n\
@@ -985,14 +1010,15 @@
       toss(&myenv); 		/* No error check in main */
       eval(&myenv);
     }
-    gc_init(&myenv);
+    gc_maybe(&myenv);
   }
   quit(&myenv);
   return EXIT_FAILURE;
 }
 
 /* "+" */
-extern void sx_2b(environment *env) {
+extern void sx_2b(environment *env)
+{
   int a, b;
   float fa, fb;
   size_t len;
@@ -1072,7 +1098,8 @@
 }
 
 /* "-" */
-extern void sx_2d(environment *env) {
+extern void sx_2d(environment *env)
+{
   int a, b;
   float fa, fb;
 
@@ -1131,7 +1158,8 @@
 }
 
 /* ">" */
-extern void sx_3e(environment *env) {
+extern void sx_3e(environment *env)
+{
   int a, b;
   float fa, fb;
 
@@ -1190,25 +1218,29 @@
 }
 
 /* "<" */
-extern void sx_3c(environment *env) {
+extern void sx_3c(environment *env) 
+{
   swap(env); if(env->err) return;
   sx_3e(env);
 }
 
 /* "<=" */
-extern void sx_3c3d(environment *env) {
+extern void sx_3c3d(environment *env)
+{
   sx_3e(env); if(env->err) return;
   not(env);
 }
 
 /* ">=" */
-extern void sx_3e3d(environment *env) {
+extern void sx_3e3d(environment *env)
+{
   sx_3c(env); if(env->err) return;
   not(env);
 }
 
 /* Return copy of a value */
-value *copy_val(environment *env, value *old_value){
+value *copy_val(environment *env, value *old_value)
+{
   stackitem *old_item, *new_item, *prev_item;
   value *new_value;
 
@@ -1255,7 +1287,8 @@
 }
 
 /* "dup"; duplicates an item on the stack */
-extern void sx_647570(environment *env) {
+extern void sx_647570(environment *env)
+{
   if((env->head)==NULL) {
     printerr("Too Few Arguments");
     env->err= 1;
@@ -1265,8 +1298,8 @@
 }
 
 /* "if", If-Then */
-extern void sx_6966(environment *env) {
-
+extern void sx_6966(environment *env)
+{
   int truth;
 
   if((env->head)==NULL || env->head->next==NULL) {
@@ -1296,8 +1329,8 @@
 }
 
 /* If-Then-Else */
-extern void ifelse(environment *env) {
-
+extern void ifelse(environment *env)
+{
   int truth;
 
   if((env->head)==NULL || env->head->next==NULL
@@ -1332,8 +1365,8 @@
 }
 
 /* "while" */
-extern void sx_7768696c65(environment *env) {
-
+extern void sx_7768696c65(environment *env)
+{
   int truth;
   value *loop, *test;
 
@@ -1378,7 +1411,8 @@
 
 
 /* "for"; for-loop */
-extern void sx_666f72(environment *env) {
+extern void sx_666f72(environment *env)
+{
   value *loop;
   int foo1, foo2;
 
@@ -1425,8 +1459,8 @@
 }
 
 /* Variant of for-loop */
-extern void foreach(environment *env) {
-  
+extern void foreach(environment *env)
+{  
   value *loop, *foo;
   stackitem *iterator;
   
@@ -1462,11 +1496,12 @@
 }
 
 /* "to" */
-extern void to(environment *env) {
-  int i, start, ending;
-  stackitem *temp_head;
-  value *temp_val;
-  
+extern void to(environment *env)
+{
+  int ending, start, i;
+  stackitem *iterator, *temp;
+  value *pack;
+
   if((env->head)==NULL || env->head->next==NULL) {
     printerr("Too Few Arguments");
     env->err=1;
@@ -1485,8 +1520,7 @@
   start= env->head->item->content.i;
   toss(env); if(env->err) return;
 
-  temp_head= env->head;
-  env->head= NULL;
+  push_sym(env, "[");
 
   if(ending>=start) {
     for(i= ending; i>=start; i--)
@@ -1496,19 +1530,44 @@
       push_int(env, i);
   }
 
-  temp_val= new_val(env);
-  protect(env, temp_val);
+  iterator= env->head;
+  pack= new_val(env);
+  protect(env, pack);
 
-  temp_val->content.ptr= env->head;
-  temp_val->type= list;
-  env->head= temp_head;
-  push_val(env, temp_val);
+  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->type!=symb
+	  || ((symbol*)(iterator->next->item->content.ptr))->id[0]!='['))
+      iterator= iterator->next;
+    
+    /* Extract list */
+    temp= env->head;
+    env->head= iterator->next;
+    iterator->next= NULL;
+
+    pack->type= list;
+    pack->content.ptr= temp;
+    
+    if(env->head!=NULL)
+      toss(env);
+  }
+
+  /* Push list */
+
+  push_val(env, pack);
 
   unprotect(env);
 }
 
 /* Read a string */
-extern void readline(environment *env) {
+extern void readline(environment *env)
+{
   char in_string[101];
 
   if(fgets(in_string, 100, env->inputstream)==NULL)
@@ -1518,7 +1577,8 @@
 }
 
 /* "read"; Read a value and place on stack */
-extern void sx_72656164(environment *env) {
+extern void sx_72656164(environment *env)
+{
   const char symbform[]= "%[a-zA-Z0-9!$%*+./:<=>?@^_~-]%n";
   const char strform[]= "\"%[^\"]\"%n";
   const char intform[]= "%i%n";
@@ -1597,8 +1657,8 @@
     return sx_72656164(env);
 }
 
-extern void beep(environment *env) {
-
+extern void beep(environment *env)
+{
   int freq, dur, period, ticks;
 
   if((env->head)==NULL || env->head->next==NULL) {
@@ -1638,11 +1698,11 @@
   default:
     abort();
   }
-};
+}
 
 /* "wait" */
-extern void sx_77616974(environment *env) {
-
+extern void sx_77616974(environment *env)
+{
   int dur;
 
   if((env->head)==NULL) {
@@ -1661,9 +1721,10 @@
   toss(env);
 
   usleep(dur);
-};
+}
 
-extern void copying(environment *env){
+extern void copying(environment *env)
+{
   printf("GNU GENERAL PUBLIC LICENSE\n\
 		       Version 2, June 1991\n\
 \n\
@@ -1922,7 +1983,8 @@
 of promoting the sharing and reuse of software generally.\n");
 }
 
-extern void warranty(environment *env){
+extern void warranty(environment *env)
+{
   printf("			    NO WARRANTY\n\
 \n\
   11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY\n\