unification of symbol tree and constant tree

7 files changed, 131 insertions, 183 deletions

diff --git a/inout.c b/inout.c
index 9a54f4fc..a7dc7413 100644
--- a/inout.c
+++ b/inout.c
@@ -5,7 +5,7 @@
 ** Also provides some predefined lua functions.
 */
 
-char *rcs_inout="$Id: inout.c,v 2.9 1994/11/08 20:06:15 roberto Exp roberto $";
+char *rcs_inout="$Id: inout.c,v 2.10 1994/11/09 18:09:22 roberto Exp roberto $";
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -150,12 +150,12 @@ void lua_reportbug (char *s)
   {
    sprintf (strchr(msg,0), 
          "\n\tin statement begining at line %d in function \"%s\" of file \"%s\"",
-         lua_debugline, lua_varname(funcstack[nfuncstack-1].function),
+         lua_debugline, lua_constant[funcstack[nfuncstack-1].function],
          funcstack[nfuncstack-1].file);
    sprintf (strchr(msg,0), "\n\tactive stack\n");
    for (i=nfuncstack-1; i>=0; i--)
     sprintf (strchr(msg,0), "\t-> function \"%s\" of file \"%s\"\n", 
-                            lua_varname(funcstack[i].function),
+                            lua_constant[funcstack[i].function],
                             funcstack[i].file);
   }
   else
diff --git a/lex.c b/lex.c
index 7aad1d0d..d0075a53 100644
--- a/lex.c
+++ b/lex.c
@@ -1,4 +1,4 @@
-char *rcs_lex = "$Id: lex.c,v 2.9 1994/11/03 17:09:20 roberto Exp roberto $";
+char *rcs_lex = "$Id: lex.c,v 2.10 1994/11/13 14:39:04 roberto Exp roberto $";
  
 
 #include <ctype.h>
@@ -7,6 +7,8 @@ char *rcs_lex = "$Id: lex.c,v 2.9 1994/11/03 17:09:20 roberto Exp roberto $";
 #include <stdlib.h>
 #include <string.h>
 
+#include "tree.h"
+#include "table.h"
 #include "opcode.h"
 #include "inout.h"
 #include "y.tab.h"
@@ -19,9 +21,8 @@ char *rcs_lex = "$Id: lex.c,v 2.9 1994/11/03 17:09:20 roberto Exp roberto $";
 #define save_and_next()  { save(current); next(); }
 
 static int current;
-static char yytext[2][256];
+static char yytext[256];
 static char *yytextLast;
-static int currentText = 0;
 
 static Input input;
 
@@ -34,7 +35,7 @@ void lua_setinput (Input fn)
 char *lua_lasttext (void)
 {
   *yytextLast = 0;
-  return yytext[currentText];
+  return yytext;
 }
 
 
@@ -87,10 +88,9 @@ static int findReserved (char *name)
 int yylex (void)
 {
   float a;
-  currentText = !currentText;
   while (1)
   {
-    yytextLast = yytext[currentText];
+    yytextLast = yytext;
 #if 0
     fprintf(stderr,"'%c' %d\n",current,current);
 #endif
@@ -110,12 +110,12 @@ int yylex (void)
         while (isalnum(current) || current == '_')
           save_and_next();
         *yytextLast = 0;
-        if (lua_strcmp(yytext[currentText], "debug") == 0)
+        if (lua_strcmp(yytext, "debug") == 0)
         {
           yylval.vInt = 1;
           return DEBUG;
         }
-        else if (lua_strcmp(yytext[currentText], "nodebug") == 0)
+        else if (lua_strcmp(yytext, "nodebug") == 0)
         {
           yylval.vInt = 0;
           return DEBUG;
@@ -179,7 +179,7 @@ int yylex (void)
         }
         next();  /* skip the delimiter */
         *yytextLast = 0;
-        yylval.pChar = yytext[currentText];
+        yylval.vWord = luaI_findconstant(lua_constcreate(yytext));
         return STRING;
       }
 
@@ -200,9 +200,9 @@ int yylex (void)
         int res;
         do { save_and_next(); } while (isalnum(current) || current == '_');
         *yytextLast = 0;
-        res = findReserved(yytext[currentText]);
+        res = findReserved(yytext);
         if (res) return res;
-        yylval.pChar = yytext[currentText];
+        yylval.pNode = lua_constcreate(yytext);
         return NAME;
       }
 
@@ -266,7 +266,7 @@ fraction:
       default:          /* also end of file */
       {
         save_and_next();
-        return yytext[currentText][0];
+        return yytext[0];
       }
     }
   }
diff --git a/lua.stx b/lua.stx
index 177e60ed..1b365942 100644
--- a/lua.stx
+++ b/lua.stx
@@ -1,6 +1,6 @@
 %{
 
-char *rcs_luastx = "$Id: lua.stx,v 3.4 1994/11/09 18:07:38 roberto Exp roberto $";
+char *rcs_luastx = "$Id: lua.stx,v 3.5 1994/11/13 14:54:18 roberto Exp roberto $";
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -9,6 +9,7 @@ char *rcs_luastx = "$Id: lua.stx,v 3.4 1994/11/09 18:07:38 roberto Exp roberto $
 #include "opcode.h"
 #include "hash.h"
 #include "inout.h"
+#include "tree.h"
 #include "table.h"
 #include "lua.h"
 
@@ -40,6 +41,7 @@ static int     nlocalvar=0;	     /* number of local variables */
 static Word    fields[MAXFIELDS];     /* fieldnames to be flushed */
 static int     nfields=0;
 
+
 /* Internal functions */
 
 static void code_byte (Byte c)
@@ -164,17 +166,6 @@ static void code_number (float f)
   }
 }
 
-static void init_function (void)
-{
- if (funcCode == NULL)  /* first function */
- {
-  funcCode = (Byte *) calloc(CODE_BLOCK, sizeof(Byte));
-  if (funcCode == NULL)
-   lua_error("not enough memory");
-  maxcode = CODE_BLOCK;
- }
-}
-             
 
 %}
 
@@ -187,6 +178,7 @@ static void init_function (void)
  Word  vWord;
  Long  vLong;
  Byte *pByte;
+ TreeNode *pNode;
 }
 
 %start functionlist
@@ -198,8 +190,8 @@ static void init_function (void)
 %token LOCAL
 %token FUNCTION
 %token <vFloat> NUMBER
-%token <pChar>  STRING
-%token <pChar>  NAME 
+%token <vWord>  STRING
+%token <pNode>  NAME 
 %token <vInt>   DEBUG
 
 %type <vLong> PrepJump
@@ -208,7 +200,7 @@ static void init_function (void)
 %type <vInt>  ffieldlist1
 %type <vInt>  lfieldlist1
 %type <vLong> var, singlevar
-
+%type <pByte> body
 
 %left AND OR
 %left EQ NE '>' '<' LE GE
@@ -239,84 +231,54 @@ functionlist : /* empty */
 
 function     : FUNCTION NAME 
                {
-                init_function();
-                pc=0; basepc=funcCode; maxcurr=maxcode; 
-                nlocalvar=0;
-                $<vWord>$ = lua_findsymbol($2); 
-               }
-               '(' parlist ')' 
-               {
-                if (lua_debug)
-                {
-                 code_byte(SETFUNCTION); 
-                 code_code((Byte *)strdup(lua_file[lua_nfile-1]));
-                 code_word($<vWord>3);
-                }
-                lua_codeadjust (0);
+                init_function($2);
                }
-               block
-               END       
+               body      
                { 
-                codereturn();
-                s_tag($<vWord>3) = LUA_T_FUNCTION;
-                s_bvalue($<vWord>3) = calloc (pc, sizeof(Byte));
-                if (s_bvalue($<vWord>3) == NULL)
-                  lua_error("not enough memory");
-                memcpy (s_bvalue($<vWord>3), basepc, pc*sizeof(Byte));
-                funcCode = basepc; maxcode=maxcurr;
+                Word func = luaI_findsymbol($2);
+                s_tag(func) = LUA_T_FUNCTION;
+                s_bvalue(func) = $4;
 #if LISTING
                 PrintCode(funcCode,funcCode+pc);
 #endif
                }
                ;
 
-method         : FUNCTION NAME { $<vWord>$ = lua_findsymbol($2); } ':' NAME
+method         : FUNCTION NAME ':' NAME
                {
-                init_function();
-                pc=0; basepc=funcCode; maxcurr=maxcode;
-                nlocalvar=0;
-                localvar[nlocalvar]=lua_findsymbol("self"); /* self param. */
+                init_function($4);
+                localvar[nlocalvar]=luaI_findsymbolbyname("self");
                 add_nlocalvar(1);
-                $<vWord>$ = lua_findconstant($5);
-               }
-               '(' parlist ')'
-               {
-                if (lua_debug)
-                {
-                 code_byte(SETFUNCTION); 
-                 code_code((Byte *)strdup(lua_file[lua_nfile-1]));
-                 code_word($<vWord>6);
-                }
-                lua_codeadjust (0);
                }
-               block
-               END
+               body
                {
-                Byte *b;
-                codereturn();
-                b = calloc (pc, sizeof(Byte));
-                if (b == NULL)
-                  lua_error("not enough memory");
-                memcpy (b, basepc, pc*sizeof(Byte));
-                funcCode = basepc; maxcode=maxcurr;
 #if LISTING
                 PrintCode(funcCode,funcCode+pc);
 #endif
                 /* assign function to table field */
                 pc=maincode; basepc=*initcode; maxcurr=maxmain;
                 nlocalvar=0;
-
-                lua_pushvar($<vWord>3+1);
+                lua_pushvar(luaI_findsymbol($2)+1);
                 code_byte(PUSHSTRING);
-                code_word($<vWord>6);
+                code_word(luaI_findconstant($4));
                 code_byte(PUSHFUNCTION);
-                code_code(b);
+                code_code($6);
                 code_byte(STOREINDEXED0);
-
                 maincode=pc; *initcode=basepc; maxmain=maxcurr;
                }
                ;
 
+body :  '(' parlist ')' block END
+        {
+          codereturn();
+          $$ = calloc (pc, sizeof(Byte));
+          if ($$ == NULL)
+            lua_error("not enough memory");
+          memcpy ($$, basepc, pc*sizeof(Byte));
+          funcCode = basepc; maxcode=maxcurr;
+        }
+                ;
+
 statlist : /* empty */
          | statlist stat sc
          ;
@@ -454,7 +416,7 @@ expr :  '(' expr ')'  { $$ = $2; }
      |  STRING
      {
       code_byte(PUSHSTRING);
-      code_word(lua_findconstant($1));
+      code_word($1);
       $$ = 1;
      }
      |  NIL             {code_byte(PUSHNIL); $$ = 1; }
@@ -493,7 +455,7 @@ funcvalue    : varexp { $$ = 0; }
              | varexp ':' NAME 
              { 
                code_byte(PUSHSTRING);
-               code_word(lua_findconstant($3));
+               code_word(luaI_findconstant($3));
                code_byte(PUSHSELF); 
                $$ = 1;
              }
@@ -516,18 +478,18 @@ exprlist1 :	expr	{ if ($1 == 0) $$ = -1; else $$ = 1; }
         }
           ;
 
-parlist  :      /* empty */
-          |     parlist1
+parlist  :      /* empty */ { lua_codeadjust(0); }
+          |     parlist1    { lua_codeadjust(0); }
           ;
                 
 parlist1 :      NAME              
                 {
-                 localvar[nlocalvar]=lua_findsymbol($1); 
+                 localvar[nlocalvar]=luaI_findsymbol($1); 
                  add_nlocalvar(1);
                 }
           |     parlist1 ',' NAME 
                 {
-                 localvar[nlocalvar]=lua_findsymbol($3); 
+                 localvar[nlocalvar]=luaI_findsymbol($3); 
                  add_nlocalvar(1);
                 }
           ;
@@ -555,9 +517,9 @@ ffieldlist1 : ffield			{$$=1;}
                 }
            ; 
 
-ffield      : NAME {$<vWord>$ = lua_findconstant($1);} '=' expr1 
+ffield      : NAME '=' expr1 
               { 
-               push_field($<vWord>2);
+               push_field(luaI_findconstant($1));
               }
            ;
 
@@ -591,14 +553,14 @@ var	  :	singlevar { $$ = $1; }
           |     varexp '.' NAME
           {
            code_byte(PUSHSTRING);
-           code_word(lua_findconstant($3));
+           code_word(luaI_findconstant($3));
            $$ = 0;              /* indexed variable */
           }
           ;
                 
 singlevar :     NAME
           {
-           Word s = lua_findsymbol($1);
+           Word s = luaI_findsymbol($1);
            int local = lua_localname (s);
            if (local == -1)     /* global var */
             $$ = s + 1;         /* return positive value */
@@ -610,10 +572,10 @@ singlevar :	NAME
 varexp  : var { lua_pushvar($1); }
         ;
           
-localdeclist  : NAME {localvar[nlocalvar]=lua_findsymbol($1); $$ = 1;}
+localdeclist  : NAME {localvar[nlocalvar]=luaI_findsymbol($1); $$ = 1;}
           | localdeclist ',' NAME 
             {
-             localvar[nlocalvar+$1]=lua_findsymbol($3); 
+             localvar[nlocalvar+$1]=luaI_findsymbol($3); 
              $$ = $1+1;
             }
           ;
@@ -676,6 +638,25 @@ static void lua_codeadjust (int n)
  }
 }
 
+static void init_function (TreeNode *func)
+{
+ if (funcCode == NULL)  /* first function */
+ {
+  funcCode = (Byte *) calloc(CODE_BLOCK, sizeof(Byte));
+  if (funcCode == NULL)
+   lua_error("not enough memory");
+  maxcode = CODE_BLOCK;
+ }
+ pc=0; basepc=funcCode; maxcurr=maxcode; 
+ nlocalvar=0;
+  if (lua_debug)
+  {
+    code_byte(SETFUNCTION); 
+    code_code((Byte *)strdup(lua_file[lua_nfile-1]));
+    code_word(luaI_findconstant(func));
+  }
+}
+
 static void codereturn (void)
 {
   if (lua_debug) code_byte(RESET); 
diff --git a/table.c b/table.c
index 8047b14a..20ab6046 100644
--- a/table.c
+++ b/table.c
@@ -3,7 +3,7 @@
 ** Module to control static tables
 */
 
-char *rcs_table="$Id: table.c,v 2.15 1994/11/10 20:41:37 roberto Exp roberto $";
+char *rcs_table="$Id: table.c,v 2.16 1994/11/11 14:00:08 roberto Exp roberto $";
 
 #include <stdlib.h>
 #include <string.h>
@@ -51,23 +51,23 @@ static void lua_initsymbol (void)
  lua_table = (Symbol *) calloc(lua_maxsymbol, sizeof(Symbol));
  if (lua_table == NULL)
    lua_error ("symbol table: not enough memory");
- n = lua_findsymbol("next");
+ n = luaI_findsymbolbyname("next");
  s_tag(n) = LUA_T_CFUNCTION; s_fvalue(n) = lua_next;
- n = lua_findsymbol("nextvar");
+ n = luaI_findsymbolbyname("nextvar");
  s_tag(n) = LUA_T_CFUNCTION; s_fvalue(n) = lua_nextvar;
- n = lua_findsymbol("type"); 
+ n = luaI_findsymbolbyname("type"); 
  s_tag(n) = LUA_T_CFUNCTION; s_fvalue(n) = luaI_type;
- n = lua_findsymbol("tonumber");
+ n = luaI_findsymbolbyname("tonumber");
  s_tag(n) = LUA_T_CFUNCTION; s_fvalue(n) = lua_obj2number;
- n = lua_findsymbol("print");
+ n = luaI_findsymbolbyname("print");
  s_tag(n) = LUA_T_CFUNCTION; s_fvalue(n) = lua_print;
- n = lua_findsymbol("dofile");
+ n = luaI_findsymbolbyname("dofile");
  s_tag(n) = LUA_T_CFUNCTION; s_fvalue(n) = lua_internaldofile;
- n = lua_findsymbol("dostring");
+ n = luaI_findsymbolbyname("dostring");
  s_tag(n) = LUA_T_CFUNCTION; s_fvalue(n) = lua_internaldostring;
- n = lua_findsymbol("setfallback");
+ n = luaI_findsymbolbyname("setfallback");
  s_tag(n) = LUA_T_CFUNCTION; s_fvalue(n) = luaI_setfallback;
- n = lua_findsymbol("error");
+ n = luaI_findsymbolbyname("error");
  s_tag(n) = LUA_T_CFUNCTION; s_fvalue(n) = luaI_error;
 }
 
@@ -89,13 +89,11 @@ void lua_initconstant (void)
 ** found, allocate it.
 ** On error, return -1.
 */
-int lua_findsymbol (char *s)
+int luaI_findsymbol (TreeNode *t)
 {
- char *n; 
  if (lua_table == NULL)
   lua_initsymbol(); 
- n = lua_varcreate(s);
- if (indexstring(n) == UNMARKED_STRING)
+ if (t->varindex == UNMARKED_STRING)
  {
   if (lua_ntable == lua_maxsymbol)
   {
@@ -106,11 +104,17 @@ int lua_findsymbol (char *s)
    if (lua_table == NULL)
      lua_error ("symbol table: not enough memory");
   }
-  indexstring(n) = lua_ntable;
+  t->varindex = lua_ntable;
   s_tag(lua_ntable) = LUA_T_NIL;
   lua_ntable++;
  }
- return indexstring(n);
+ return t->varindex;
+}
+
+
+int luaI_findsymbolbyname (char *name)
+{
+  return luaI_findsymbol(lua_constcreate(name));
 }
 
 
@@ -119,13 +123,11 @@ int lua_findsymbol (char *s)
 ** found, allocate it.
 ** On error, return -1.
 */
-int lua_findconstant (char *s)
+int luaI_findconstant (TreeNode *t)
 {
- char *n;
  if (lua_constant == NULL)
   lua_initconstant();
- n = lua_constcreate(s);
- if (indexstring(n) == UNMARKED_STRING)
+ if (t->constindex == UNMARKED_STRING)
  {
   if (lua_nconstant == lua_maxconstant)
   {
@@ -136,11 +138,11 @@ int lua_findconstant (char *s)
    if (lua_constant == NULL)
      lua_error ("constant table: not enough memory");
   }
-  indexstring(n) = lua_nconstant;
-  lua_constant[lua_nconstant] = n;
+  t->constindex = lua_nconstant;
+  lua_constant[lua_nconstant] = t->str;
   lua_nconstant++;
  }
- return indexstring(n);
+ return t->constindex;
 }
 
 
diff --git a/table.h b/table.h
index a885f201..423ba3dd 100644
--- a/table.h
+++ b/table.h
@@ -1,12 +1,14 @@
 /*
 ** Module to control static tables
 ** TeCGraf - PUC-Rio
-** $Id: table.h,v 2.3 1994/10/17 19:03:23 celes Exp roberto $
+** $Id: table.h,v 2.4 1994/11/03 21:48:36 roberto Exp roberto $
 */
 
 #ifndef table_h
 #define table_h
 
+#include "tree.h"
+
 extern Symbol *lua_table;
 extern char  **lua_constant;
 
@@ -19,8 +21,9 @@ extern Word    lua_recovered;
 
 
 void  lua_initconstant (void);
-int   lua_findsymbol      (char *s);
-int   lua_findconstant    (char *s);
+int   luaI_findsymbolbyname (char *name);
+int   luaI_findsymbol      (TreeNode *t);
+int   luaI_findconstant    (TreeNode *t);
 void  lua_travsymbol      (void (*fn)(Object *));
 void  lua_markobject      (Object *o);
 void  lua_pack            (void);
diff --git a/tree.c b/tree.c
index ae5a19de..bca29994 100644
--- a/tree.c
+++ b/tree.c
@@ -3,7 +3,7 @@
 ** TecCGraf - PUC-Rio
 */
  
-char *rcs_tree="$Id: tree.c,v 1.2 1994/10/18 17:36:11 celes Exp roberto $";
+char *rcs_tree="$Id: tree.c,v 1.3 1994/11/10 20:41:37 roberto Exp roberto $";
 
 
 #include <stdlib.h>
@@ -17,22 +17,13 @@ char *rcs_tree="$Id: tree.c,v 1.2 1994/10/18 17:36:11 celes Exp roberto $";
 #define lua_strcmp(a,b) (a[0]<b[0]?(-1):(a[0]>b[0]?(1):strcmp(a,b))) 
 
 
-typedef struct TreeNode
-{
- struct TreeNode *right;
- struct TreeNode *left;
- Word            index;
- char            str[1];        /* \0 byte already reserved */
-} TreeNode;
-
 static TreeNode *string_root = NULL;
 static TreeNode *constant_root = NULL;
-static TreeNode *variable_root = NULL;
 
 /*
 ** Insert a new string/constant/variable at the tree. 
 */
-static char *tree_create (TreeNode **node, char *str, int *created)
+static TreeNode *tree_create (TreeNode **node, char *str, int *created)
 {
  if (*node == NULL)
  {
@@ -41,9 +32,9 @@ static char *tree_create (TreeNode **node, char *str, int *created)
     lua_error("not enough memory");
   (*node)->left = (*node)->right = NULL;
   strcpy((*node)->str, str);
-  (*node)->index = UNMARKED_STRING;
+  (*node)->varindex = (*node)->constindex = UNMARKED_STRING;
   *created = 1;
-  return (*node)->str;
+  return *node;
  }
  else
  {
@@ -53,35 +44,28 @@ static char *tree_create (TreeNode **node, char *str, int *created)
   else if (c > 0)
    return tree_create(&(*node)->right, str, created);
   else
-   return (*node)->str;
+   return *node;
  }
 }
 
 char *lua_strcreate (char *str) 
 {
  int created=0;
- char *s = tree_create(&string_root, str, &created);
+ TreeNode *t = tree_create(&string_root, str, &created);
  if (created)
  {
   if (lua_nentity == lua_block) lua_pack ();
   lua_nentity++;
  }
- return s;
+ return t->str;
 }
 
-char *lua_constcreate (char *str) 
+TreeNode *lua_constcreate (char *str) 
 {
  int created;
  return tree_create(&constant_root, str, &created);
 }
 
-char *lua_varcreate (char *str) 
-{
- int created;
- return tree_create(&variable_root, str, &created);
-}
-
-
 
 /*
 ** Free a node of the tree
@@ -141,14 +125,14 @@ static TreeNode *lua_travcollector (TreeNode *r)
  if (r == NULL) return NULL;
  r->right = lua_travcollector(r->right);
  r->left  = lua_travcollector(r->left);
- if (r->index == UNMARKED_STRING) 
+ if (r->constindex == UNMARKED_STRING) 
  {
   ++lua_recovered;
   return lua_strfree(r);
  }
  else
  {
-  r->index = UNMARKED_STRING;
+  r->constindex = UNMARKED_STRING;
   return r;
  }
 }
@@ -168,18 +152,6 @@ void lua_strcollector (void)
 */
 static TreeNode *tree_next (TreeNode *node, char *str)
 {
-#if 0
- if (node == NULL) return NULL;
- if (str == NULL || lua_strcmp(str, node->str) < 0)
- {
-  TreeNode *result = tree_next(node->left, str);
-  return result == NULL ? node : result;
- }
- else
- {
-  return tree_next(node->right, str);
- }
-#else
  if (node == NULL) return NULL;
  else if (str == NULL) return node;
  else
@@ -195,30 +167,11 @@ static TreeNode *tree_next (TreeNode *node, char *str)
   else
    return tree_next(node->right, str);
  }
-#endif
 }
 
 char *lua_varnext (char *n)
 {
- TreeNode *result = tree_next(variable_root, n);
+ TreeNode *result = tree_next(constant_root, n);
  return result != NULL ? result->str : NULL;
 }
 
-
-/*
-** Given an id, find the string with exaustive search
-*/
-static char *tree_name (TreeNode *node, Word index)
-{
- if (node == NULL) return NULL;
- if (node->index == index) return node->str;
- else
- {
-  char *result = tree_name(node->left, index);
-  return result != NULL ? result : tree_name(node->right, index);
- }
-}
-char *lua_varname (Word index)
-{
- return tree_name(variable_root, index);
-}
diff --git a/tree.h b/tree.h
index b1099e4e..0e7c27c9 100644
--- a/tree.h
+++ b/tree.h
@@ -1,7 +1,7 @@
 /*
 ** tree.h
 ** TecCGraf - PUC-Rio
-** $Id: $
+** $Id: tree.h,v 1.1 1994/07/19 21:24:17 celes Exp roberto $
 */
 
 #ifndef tree_h
@@ -14,14 +14,23 @@
 #define MARKED_STRING   0xFFFE
 #define MAX_WORD        0xFFFD
 
+ 
+typedef struct TreeNode
+{
+ struct TreeNode *right;
+ struct TreeNode *left;
+ Word varindex;  /* if this is a symbol */
+ Word constindex;  /* if this is a constant; also used for garbage collection */
+ char            str[1];        /* \0 byte already reserved */
+} TreeNode;
+
+
 #define indexstring(s) (*(((Word *)s)-1))
 
 
 char *lua_strcreate    (char *str);
-char *lua_constcreate  (char *str);
-char *lua_varcreate    (char *str);
+TreeNode *lua_constcreate  (char *str);
 void  lua_strcollector (void);
 char *lua_varnext      (char *n);
-char *lua_varname      (Word index);
 
 #endif