private static void block(LexState ls)
{
/* block . chunk */
FuncState fs = ls.fs;
BlockCnt bl = new BlockCnt();
enterblock(fs, bl, 0);
chunk(ls);
Lua.lua_assert(bl.breaklist == Lua.NO_JUMP);
leaveblock(fs);
}
private static void enterblock(FuncState fs, BlockCnt bl, lu_byte isbreakable)
{
bl.breaklist = Lua.NO_JUMP;
bl.continuelist = Lua.NO_JUMP;
bl.isbreakable = isbreakable;
bl.nactvar = fs.nactvar;
bl.upval = 0;
bl.previous = fs.bl;
fs.bl = bl;
Lua.lua_assert(fs.freereg == fs.nactvar);
}
private static void forstat(LexState ls, int line)
{
/* forstat . FOR (fornum | forlist) END */
FuncState fs = ls.fs;
TString varname;
BlockCnt bl = new BlockCnt();
enterblock(fs, bl, 1); /* scope for loop and control variables */
Lua.luaX_next(ls); /* skip `for' */
varname = str_checkname(ls); /* first variable name */
switch (ls.t.token)
{
case '=': fornum(ls, varname, line); break;
case ',':
case (int)RESERVED.TK_IN:
forlist(ls, varname);
break;
default: Lua.luaX_syntaxerror(ls, Lua.LUA_QL("=") + " or " + Lua.LUA_QL("in") + " expected"); break;
}
check_match(ls, (int)RESERVED.TK_END, (int)RESERVED.TK_FOR, line);
leaveblock(fs); /* loop scope (`break' jumps to this point) */
}
private static void forbody(LexState ls, int base_, int line, int nvars, int isnum)
{
/* forbody . DO block */
BlockCnt bl = new BlockCnt();
FuncState fs = ls.fs;
int prep, endfor;
adjustlocalvars(ls, 3); /* control variables */
checknext(ls, (int)RESERVED.TK_DO);
prep = (isnum != 0) ? Lua.luaK_codeAsBx(fs, OpCode.OP_FORPREP, base_, Lua.NO_JUMP) : Lua.luaK_jump(fs);
enterblock(fs, bl, 0); /* scope for declared variables */
adjustlocalvars(ls, nvars);
Lua.luaK_reserveregs(fs, nvars);
block(ls);
leaveblock(fs); /* end of scope for declared variables */
Lua.luaK_patchtohere(fs, prep);
Lua.luaK_patchtohere(fs, bl.previous.continuelist); /* continue, if any, jumps to here */
endfor = (isnum != 0) ? Lua.luaK_codeAsBx(fs, OpCode.OP_FORLOOP, base_, Lua.NO_JUMP) :
Lua.luaK_codeABC(fs, OpCode.OP_TFORLOOP, base_, 0, nvars);
Lua.luaK_fixline(fs, line); /* pretend that `OP_FOR' starts the loop */
Lua.luaK_patchlist(fs, ((isnum != 0) ? endfor : Lua.luaK_jump(fs)), prep + 1);
}
private static void repeatstat(LexState ls, int line)
{
/* repeatstat . REPEAT block UNTIL cond */
int condexit;
FuncState fs = ls.fs;
int repeat_init = Lua.luaK_getlabel(fs);
BlockCnt bl1 = new BlockCnt(), bl2 = new BlockCnt();
enterblock(fs, bl1, 1); /* loop block */
enterblock(fs, bl2, 0); /* scope block */
Lua.luaX_next(ls); /* skip REPEAT */
chunk(ls);
Lua.luaK_patchtohere(fs, bl1.continuelist);
check_match(ls, (int)RESERVED.TK_UNTIL, (int)RESERVED.TK_REPEAT, line);
condexit = cond(ls); /* read condition (inside scope block) */
if (bl2.upval == 0)
{ /* no upvalues? */
leaveblock(fs); /* finish scope */
Lua.luaK_patchlist(ls.fs, condexit, repeat_init); /* close the loop */
}
else
{ /* complete semantics when there are upvalues */
breakstat(ls); /* if condition then break */
Lua.luaK_patchtohere(ls.fs, condexit); /* else... */
leaveblock(fs); /* finish scope... */
Lua.luaK_patchlist(ls.fs, Lua.luaK_jump(fs), repeat_init); /* and repeat */
}
leaveblock(fs); /* finish loop */
}
private static void whilestat(LexState ls, int line)
{
/* whilestat . WHILE cond DO block END */
FuncState fs = ls.fs;
int whileinit;
int condexit;
BlockCnt bl = new BlockCnt();
Lua.luaX_next(ls); /* skip WHILE */
whileinit = Lua.luaK_getlabel(fs);
condexit = cond(ls);
enterblock(fs, bl, 1);
checknext(ls, (int)RESERVED.TK_DO);
block(ls);
Lua.luaK_patchlist(fs, Lua.luaK_jump(fs), whileinit);
Lua.luaK_patchlist(fs, bl.continuelist, whileinit); /* continue goes to start, too */
check_match(ls, (int)RESERVED.TK_END, (int)RESERVED.TK_WHILE, line);
leaveblock(fs);
Lua.luaK_patchtohere(fs, condexit); /* false conditions finish the loop */
}