commit 7b65328c8e89ecc999e47d00288bfa4cf6692cdc
parent d2e05589d738c3a1b563879435d5cc0830719fd1
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Tue, 9 Apr 2002 16:47:22 -0300
new semantics for `generic for' (with state)
Diffstat:
5 files changed, 35 insertions(+), 31 deletions(-)
diff --git a/ldebug.c b/ldebug.c
@@ -1,5 +1,5 @@
/*
-** $Id: ldebug.c,v 1.105 2002/03/25 17:47:14 roberto Exp roberto $
+** $Id: ldebug.c,v 1.106 2002/04/04 17:21:31 roberto Exp roberto $
** Debug Interface
** See Copyright Notice in lua.h
*/
@@ -347,8 +347,7 @@ static Instruction luaG_symbexec (const Proto *pt, int lastpc, int reg) {
break;
}
case OP_TFORLOOP: {
- checkreg(pt, a+c);
- checkreg(pt, a+2); /* at least 2 for table generators */
+ checkreg(pt, a+2+c);
check(pc+2 < pt->sizecode); /* check skip */
break;
}
diff --git a/lopcodes.c b/lopcodes.c
@@ -1,5 +1,5 @@
/*
-** $Id: lopcodes.c,v 1.13 2002/03/21 20:32:22 roberto Exp roberto $
+** $Id: lopcodes.c,v 1.14 2002/03/25 17:47:14 roberto Exp roberto $
** extracted automatically from lopcodes.h by mkprint.lua
** DO NOT EDIT
** See Copyright Notice in lua.h
@@ -49,6 +49,7 @@ const char *const luaP_opnames[] = {
"RETURN",
"FORLOOP",
"TFORLOOP",
+ "OP_TFORPREP",
"SETLIST",
"SETLISTO",
"CLOSE",
@@ -98,6 +99,7 @@ const lu_byte luaP_opmodes[NUM_OPCODES] = {
,opmode(0,0,0,0, 0,0,iABC) /* OP_RETURN */
,opmode(0,0,0,0, 0,0,iAsBc) /* OP_FORLOOP */
,opmode(0,0,0,0, 0,0,iABC) /* OP_TFORLOOP */
+ ,opmode(0,0,0,0, 0,0,iABC) /* OP_TFORPREP */
,opmode(0,0,0,0, 0,0,iABc) /* OP_SETLIST */
,opmode(0,0,0,0, 0,0,iABc) /* OP_SETLISTO */
,opmode(0,0,0,0, 0,0,iABC) /* OP_CLOSE */
diff --git a/lopcodes.h b/lopcodes.h
@@ -1,5 +1,5 @@
/*
-** $Id: lopcodes.h,v 1.92 2002/03/21 20:32:22 roberto Exp roberto $
+** $Id: lopcodes.h,v 1.93 2002/03/25 17:47:14 roberto Exp roberto $
** Opcodes for Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -173,8 +173,9 @@ OP_RETURN,/* A B return R(A), ... ,R(A+B-2) (see (3)) */
OP_FORLOOP,/* A sBc R(A)+=R(A+2); if R(A) <?= R(A+1) then PC+= sBc */
-OP_TFORLOOP,/* A C R(A+1), ... ,R(A+C) := R(A)();
- if R(A+1) ~= nil then pc++ */
+OP_TFORLOOP,/* A C R(A+2), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2));
+ if R(A+2) ~= nil then pc++ */
+OP_TFORPREP,/* A if type(R(A)) == table then R(A+1):=R(A), R(A):=next */
OP_SETLIST,/* A Bc R(A)[Bc-Bc%FPF+i] := R(A+i), 1 <= i <= Bc%FPF+1 */
OP_SETLISTO,/* A Bc */
diff --git a/lparser.c b/lparser.c
@@ -1,5 +1,5 @@
/*
-** $Id: lparser.c,v 1.173 2002/03/25 17:47:14 roberto Exp roberto $
+** $Id: lparser.c,v 1.174 2002/04/02 20:34:15 roberto Exp roberto $
** Lua Parser
** See Copyright Notice in lua.h
*/
@@ -331,6 +331,7 @@ static void enterblock (FuncState *fs, BlockCnt *bl, int isbreakable) {
bl->upval = 0;
bl->previous = fs->bl;
fs->bl = bl;
+ lua_assert(fs->freereg == fs->nactloc);
}
@@ -1028,24 +1029,25 @@ static void fornum (LexState *ls, TString *varname, int line) {
static void forlist (LexState *ls, TString *indexname) {
- /* forlist -> NAME {,NAME} IN exp1 DO body */
+ /* forlist -> NAME {,NAME} IN explist1 DO body */
FuncState *fs = ls->fs;
+ expdesc e;
int nvars = 0;
int prep;
int base = fs->freereg;
- new_localvarstr(ls, "(for generator)", 0);
- new_localvar(ls, indexname, ++nvars);
+ new_localvarstr(ls, "(for generator)", nvars++);
+ new_localvarstr(ls, "(for state)", nvars++);
+ new_localvar(ls, indexname, nvars++);
while (optional(ls, ',')) {
- new_localvar(ls, str_checkname(ls), ++nvars);
+ new_localvar(ls, str_checkname(ls), nvars++);
next(ls);
}
check(ls, TK_IN);
- exp1(ls); /* table */
- luaK_checkstack(fs, 2); /* at least two slots, to traverse tables */
- luaK_reserveregs(fs, nvars); /* registers for vars */
- luaK_codeABC(fs, OP_LOADNIL, base+1, base+nvars, 0);
- adjustlocalvars(ls, nvars+1); /* scope for control variables */
- luaK_codeABC(fs, OP_TFORLOOP, base, 0, nvars);
+ adjust_assign(ls, 3, explist1(ls, &e), &e);
+ luaK_reserveregs(fs, nvars - 3); /* registers for other variables */
+ luaK_codeABC(fs, OP_TFORPREP, base, 0, 0);
+ luaK_codeABC(fs, OP_TFORLOOP, base, 0, nvars - 3);
+ adjustlocalvars(ls, nvars); /* scope for all variables */
prep = luaK_jump(fs);
check(ls, TK_DO);
block(ls);
diff --git a/lvm.c b/lvm.c
@@ -1,5 +1,5 @@
/*
-** $Id: lvm.c,v 1.222 2002/03/22 16:54:31 roberto Exp roberto $
+** $Id: lvm.c,v 1.223 2002/03/25 17:47:14 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@@ -549,21 +549,21 @@ StkId luaV_execute (lua_State *L) {
break;
}
case OP_TFORLOOP: {
+ setobj(ra+4, ra+2);
+ setobj(ra+3, ra+1);
+ setobj(ra+2, ra);
+ L->top = ra+5;
+ luaD_call(L, ra+2, GETARG_C(i) + 1);
+ L->top = L->ci->top;
+ if (ttype(ra+2) != LUA_TNIL) pc++; /* skip jump (keep looping) */
+ break;
+ }
+ case OP_TFORPREP: {
if (ttype(ra) == LUA_TTABLE) {
- Table *t = hvalue(ra);
- if (luaH_next(L, t, ra+1))
- pc++; /* skip jump (keep looping) */
- }
- else if (ttype(ra) == LUA_TFUNCTION) {
setobj(ra+1, ra);
- L->top = ra+2; /* no arguments */
- luaD_call(L, ra+1, GETARG_C(i));
- L->top = L->ci->top;
- if (ttype(ra+1) != LUA_TNIL)
- pc++; /* skip jump (keep looping) */
+ setsvalue(ra, luaS_new(L, "next"));
+ luaV_gettable(L, gt(L), ra, ra);
}
- else
- luaD_error(L, "`for' generator must be a table or function");
break;
}
case OP_SETLIST:
