commit 26794616374fee54532d0030ae006abb77dfb7ba
parent 0870a2d1d8a1434eecae1923886ba219c4e699c7
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 10 Mar 1999 11:09:23 -0300
no more assignment expressions (they don't fit in Lua...)
Diffstat:
4 files changed, 20 insertions(+), 83 deletions(-)
diff --git a/lopcodes.h b/lopcodes.h
@@ -1,5 +1,5 @@
/*
-** $Id: lopcodes.h,v 1.30 1999/03/04 21:15:50 roberto Exp roberto $
+** $Id: lopcodes.h,v 1.31 1999/03/05 21:16:07 roberto Exp roberto $
** Opcodes for Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -26,7 +26,6 @@ TAILCALL,/* b c v_c...v_1 f (return) f(v1,...,v_c) */
PUSHNIL,/* b - nil_0...nil_b */
POP,/* b a_b...a_1 - */
-POPDUP,/* b v a_b...a_1 v */
PUSHNUMBERW,/* w - (float)w */
PUSHNUMBER,/* b - (float)b */
@@ -56,18 +55,13 @@ CREATEARRAYW,/* w - newarray(size = w) */
CREATEARRAY,/* b - newarray(size = b) */
SETLOCAL,/* b x - LOC[b]=x */
-SETLOCALDUP,/* b x x LOC[b]=x */
SETGLOBALW,/* w x - VAR[CNST[w]]=x */
SETGLOBAL,/* b x - VAR[CNST[b]]=x */
-SETGLOBALDUPW,/*w x x VAR[CNST[w]]=x */
-SETGLOBALDUP,/* b x x VAR[CNST[b]]=x */
SETTABLEPOP,/* - v i t - t[i]=v */
-SETTABLEPOPDUP,/* - v i t v t[i]=v */
SETTABLE,/* b v a_b...a_1 i t a_b...a_1 i t t[i]=v */
-SETTABLEDUP,/* b v a_b...a_1 i t v a_b...a_1 i t t[i]=v */
SETLISTW,/* w c v_c...v_1 t t t[i+w*FPF]=v_i */
SETLIST,/* b c v_c...v_1 t t t[i+b*FPF]=v_i */
diff --git a/lparser.c b/lparser.c
@@ -1,5 +1,5 @@
/*
-** $Id: lparser.c,v 1.26 1999/03/04 21:17:26 roberto Exp roberto $
+** $Id: lparser.c,v 1.27 1999/03/05 21:16:07 roberto Exp roberto $
** LL(1) Parser and code generator for Lua
** See Copyright Notice in lua.h
*/
@@ -99,7 +99,7 @@ typedef struct FuncState {
/*
** prototypes for non-terminal functions
*/
-static int assignment (LexState *ls, vardesc *v, int nvars, OpCode *codes);
+static int assignment (LexState *ls, vardesc *v, int nvars);
static int cond (LexState *ls);
static int funcname (LexState *ls, vardesc *v);
static int funcparams (LexState *ls, int slf);
@@ -114,7 +114,6 @@ static void chunk (LexState *ls);
static void constructor (LexState *ls);
static void decinit (LexState *ls, listdesc *d);
static void exp0 (LexState *ls, vardesc *v);
-static void Gexp (LexState *ls, vardesc *v);
static void exp1 (LexState *ls);
static void exp2 (LexState *ls, vardesc *v);
static void explist (LexState *ls, listdesc *e);
@@ -467,22 +466,16 @@ static void lua_pushvar (LexState *ls, vardesc *var) {
}
-/* to be used by "storevar" and assignment */
-static OpCode set_pop[] = {SETLOCAL, SETGLOBAL, SETTABLEPOP, SETTABLE};
-static OpCode set_dup[] = {SETLOCALDUP, SETGLOBALDUP, SETTABLEPOPDUP,
- SETTABLEDUP};
-
-
-static void storevar (LexState *ls, vardesc *var, OpCode *codes) {
+static void storevar (LexState *ls, vardesc *var) {
switch (var->k) {
case VLOCAL:
- code_oparg(ls, codes[0], var->info, -1);
+ code_oparg(ls, SETLOCAL, var->info, -1);
break;
case VGLOBAL:
- code_oparg(ls, codes[1], var->info, -1);
+ code_oparg(ls, SETGLOBAL, var->info, -1);
break;
case VINDEXED:
- code_opcode(ls, codes[2], -3);
+ code_opcode(ls, SETTABLEPOP, -3);
break;
default:
LUA_INTERNALERROR("invalid var kind to store");
@@ -739,7 +732,7 @@ static int stat (LexState *ls) {
next(ls);
needself = funcname(ls, &v);
body(ls, needself, line);
- storevar(ls, &v, set_pop);
+ storevar(ls, &v);
return 1;
}
@@ -765,7 +758,7 @@ static int stat (LexState *ls) {
close_exp(ls, v.info, 0);
}
else { /* stat -> ['%'] NAME assignment */
- int left = assignment(ls, &v, 1, set_pop);
+ int left = assignment(ls, &v, 1);
adjuststack(ls, left); /* remove eventual 'garbage' left on stack */
}
return 1;
@@ -948,19 +941,6 @@ static void exp0 (LexState *ls, vardesc *v) {
}
-static void Gexp (LexState *ls, vardesc *v) {
- /* Gexp -> exp0 | assignment */
- exp0(ls, v);
- if (v->k != VEXP && (ls->token == '=' || ls->token == ',')) {
- int left = assignment(ls, v, 1, set_dup);
- deltastack(ls, 1); /* DUP operations push an extra value */
- if (left > 0)
- code_oparg(ls, POPDUP, left, -left);
- v->k = VEXP; v->info = 0; /* this expression is closed now */
- }
-}
-
-
static void push (LexState *ls, stack_op *s, int op) {
if (s->top >= MAXOPS)
luaX_error(ls, "expression too complex");
@@ -1015,9 +995,9 @@ static void simpleexp (LexState *ls, vardesc *v, stack_op *s) {
ifpart(ls, 1, ls->linenumber);
break;
- case '(': /* simpleexp -> '(' Gexp ')' */
+ case '(': /* simpleexp -> '(' exp0 ')' */
next(ls);
- Gexp(ls, v);
+ exp0(ls, v);
check(ls, ')');
return;
@@ -1239,7 +1219,7 @@ static void decinit (LexState *ls, listdesc *d) {
}
-static int assignment (LexState *ls, vardesc *v, int nvars, OpCode *codes) {
+static int assignment (LexState *ls, vardesc *v, int nvars) {
int left = 0;
unloaddot(ls, v);
if (ls->token == ',') { /* assignment -> ',' NAME assignment */
@@ -1248,7 +1228,7 @@ static int assignment (LexState *ls, vardesc *v, int nvars, OpCode *codes) {
var_or_func(ls, &nv);
if (nv.k == VEXP)
luaX_error(ls, "syntax error");
- left = assignment(ls, &nv, nvars+1, set_pop);
+ left = assignment(ls, &nv, nvars+1);
}
else { /* assignment -> '=' explist1 */
listdesc d;
@@ -1258,15 +1238,16 @@ static int assignment (LexState *ls, vardesc *v, int nvars, OpCode *codes) {
}
if (v->k != VINDEXED || left+(nvars-1) == 0) {
/* global/local var or indexed var without values in between */
- storevar(ls, v, codes);
+ storevar(ls, v);
}
else { /* indexed var with values in between*/
- code_oparg(ls, codes[3], left+(nvars-1), -1);
- left += 2; /* table/index are not popped, because they aren't on top */
+ code_oparg(ls, SETTABLE, left+(nvars-1), -1);
+ left += 2; /* table&index are not popped, because they aren't on top */
}
return left;
}
+
static void constructor (LexState *ls) {
/* constructor -> '{' part [';' part] '}' */
int line = ls->linenumber;
diff --git a/lvm.c b/lvm.c
@@ -1,5 +1,5 @@
/*
-** $Id: lvm.c,v 1.52 1999/03/04 21:15:50 roberto Exp roberto $
+** $Id: lvm.c,v 1.53 1999/03/05 21:16:07 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -356,11 +356,6 @@ StkId luaV_execute (Closure *cl, TProtoFunc *tf, StkId base) {
S->top -= aux;
break;
- case POPDUP: aux = *pc++;
- *(S->top-aux-1) = *(S->top-1);
- S->top -= aux;
- break;
-
case PUSHNUMBERW: aux += highbyte(*pc++);
case PUSHNUMBER: aux += *pc++;
ttype(S->top) = LUA_T_NUMBER;
@@ -424,45 +419,20 @@ StkId luaV_execute (Closure *cl, TProtoFunc *tf, StkId base) {
*((S->stack+base) + aux) = *(--S->top);
break;
- case SETLOCALDUP: aux = *pc++;
- *((S->stack+base) + aux) = *(S->top-1);
- break;
-
case SETGLOBALW: aux += highbyte(*pc++);
case SETGLOBAL: aux += *pc++;
luaV_setglobal(tsvalue(&consts[aux]));
break;
- case SETGLOBALDUPW: aux += highbyte(*pc++);
- case SETGLOBALDUP: aux += *pc++;
- *S->top = *(S->top-1);
- S->top++;
- luaV_setglobal(tsvalue(&consts[aux]));
- break;
-
case SETTABLEPOP:
luaV_settable(S->top-3);
S->top -= 2; /* pop table and index */
break;
- case SETTABLEPOPDUP: {
- TObject temp = *(S->top-1);
- luaV_settable(S->top-3);
- S->top--; /* pop index (temp goes into "table" position) */
- *(S->top-1) = temp;
- break;
- }
-
case SETTABLE:
luaV_settable(S->top-3-(*pc++));
break;
- case SETTABLEDUP:
- *S->top = *(S->top-1);
- S->top++;
- luaV_settable(S->top-(3+1)-(*pc++));
- break;
-
case SETLISTW: aux += highbyte(*pc++);
case SETLIST: aux += *pc++; {
int n = *(pc++);
diff --git a/manual.tex b/manual.tex
@@ -1,4 +1,4 @@
-% $Id: manual.tex,v 1.24 1999/02/25 19:13:56 roberto Exp roberto $
+% $Id: manual.tex,v 1.25 1999/03/04 21:23:39 roberto Exp roberto $
\documentclass[11pt]{article}
\usepackage{fullpage,bnf}
@@ -41,7 +41,7 @@ Waldemar Celes
\tecgraf\ --- Computer Science Department --- PUC-Rio
}
-%\date{\small \verb$Date: 1999/02/25 19:13:56 $}
+%\date{\small \verb$Date: 1999/03/04 21:23:39 $}
\maketitle
@@ -697,14 +697,6 @@ according to its condition.
Its final value is the value of the chosen expression.
An absent else-part is equivalent to \verb|else nil|.
-\subsubsection{Assignment Expressions}
-\begin{Produc}
-\produc{exp}{\ter{(} varlist1 \ter{=} explist1 \ter{)}}
-\end{Produc}%
-An \Index{assignment expression} executes a multiple assignment,
-and results in the final value of its first right hand expression
-(that is, the value assigned to the first variable in the variable list).
-
\subsubsection{Table Constructors} \label{tableconstructor}
Table \Index{constructors} are expressions that create tables;
every time a constructor is evaluated, a new table is created.
