/*
** subexpr -> (simpleexp | unop subexpr) { binop subexpr }
** where `binop' is any binary operator with a priority higher than `limit'
*/
static BinOpr subexpr (LexState *ls, expdesc *v, unsigned int limit) {
BinOpr op;
UnOpr uop;
enterlevel(ls);
uop = getunopr(ls->t.token);
if (uop != OPR_NOUNOPR) {
luaX_next(ls);
subexpr(ls, v, UNARY_PRIORITY);
luaK_prefix(ls->fs, uop, v);
}
else simpleexp(ls, v);
/* expand while operators have priorities higher than `limit' */
op = getbinopr(ls->t.token);
while (op != OPR_NOBINOPR && priority[op].left > limit) {
expdesc v2;
BinOpr nextop;
luaX_next(ls);
luaK_infix(ls->fs, op, v);
/* read sub-expression with higher priority */
nextop = subexpr(ls, &v2, priority[op].right);
luaK_posfix(ls->fs, op, v, &v2);
op = nextop;
}
leavelevel(ls);
return op; /* return first untreated operator */
}
/*
** subexpr -> (simpleexp | unop subexpr) { binop subexpr }
** where `binop' is any binary operator with a priority higher than `limit'
*/
static BinOpr subexpr (LexState *ls, expdesc *v, unsigned int limit)
{
callstack_ref cref( *ls->L );
UnOpr uop = getunopr(ls->t.token);
FuncState *fs = GetCurrentFuncState( ls );
if (uop != OPR_NOUNOPR)
{
luaX_next(ls);
subexpr(ls, v, UNARY_PRIORITY);
luaK_prefix(fs, uop, v);
}
else
{
simpleexp(ls, v);
}
/* expand while operators have priorities higher than `limit' */
BinOpr op = getbinopr(ls->t.token);
while (op != OPR_NOBINOPR && priority[op].left > limit)
{
luaX_next(ls);
luaK_infix(fs, op, v);
/* read sub-expression with higher priority */
expdesc v2;
BinOpr nextop = subexpr(ls, &v2, priority[op].right);
luaK_posfix(fs, op, v, &v2);
op = nextop;
}
return op; /* return first untreated operator */
}
static void primaryexp (LexState *ls, expdesc *v) {
/* primaryexp ->
prefixexp { `.' NAME | `[' exp `]' | `:' NAME funcargs | funcargs } */
FuncState *fs = ls->fs;
prefixexp(ls, v);
for (;;) {
switch (ls->t.token) {
case '.': { /* field */
field(ls, v);
break;
}
case '[': { /* `[' exp1 `]' */
expdesc key;
luaK_exp2anyreg(fs, v);
yindex(ls, &key);
luaK_indexed(fs, v, &key);
break;
}
case ':': { /* `:' NAME funcargs */
expdesc key;
luaX_next(ls);
checkname(ls, &key);
luaK_self(fs, v, &key);
funcargs(ls, v);
break;
}
#if LUA_WIDESTRING
case '(': case TK_STRING: case TK_WSTRING: case '{': { /* funcargs */
#else
case '(': case TK_STRING: case '{': { /* funcargs */
#endif /* LUA_WIDESTRING */
luaK_exp2nextreg(fs, v);
funcargs(ls, v);
break;
}
default: return;
}
}
}
static void simpleexp (LexState *ls, expdesc *v) {
#if LUA_WIDESTRING
/* simpleexp -> NUMBER | STRING | WSTRING | NIL | true | false | ... |
constructor | FUNCTION body | primaryexp */
#else
/* simpleexp -> NUMBER | STRING | NIL | true | false | ... |
constructor | FUNCTION body | primaryexp */
#endif /* LUA_WIDESTRING */
switch (ls->t.token) {
case TK_NUMBER: {
init_exp(v, VKNUM, 0);
v->u.nval = ls->t.seminfo.r;
break;
}
case TK_STRING: {
codestring(ls, v, ls->t.seminfo.ts);
break;
}
#if LUA_WIDESTRING
case TK_WSTRING: {
codewstring(ls, v, ls->t.seminfo.ts);
break;
}
#endif /* LUA_WIDESTRING */
case TK_NIL: {
init_exp(v, VNIL, 0);
break;
}
case TK_TRUE: {
init_exp(v, VTRUE, 0);
break;
}
case TK_FALSE: {
init_exp(v, VFALSE, 0);
break;
}
case TK_DOTS: { /* vararg */
FuncState *fs = ls->fs;
check_condition(ls, fs->f->is_vararg,
"cannot use " LUA_QL("...") " outside a vararg function");
fs->f->is_vararg &= ~VARARG_NEEDSARG; /* don't need 'arg' */
init_exp(v, VVARARG, luaK_codeABC(fs, OP_VARARG, 0, 1, 0));
break;
}
case '{': { /* constructor */
constructor(ls, v);
return;
}
case TK_FUNCTION: {
luaX_next(ls);
body(ls, v, 0, ls->linenumber);
return;
}
default: {
primaryexp(ls, v);
return;
}
}
luaX_next(ls);
}
static UnOpr getunopr (int op) {
switch (op) {
case TK_NOT: return OPR_NOT;
case '-': return OPR_MINUS;
case '#': return OPR_LEN;
default: return OPR_NOUNOPR;
}
}
static BinOpr getbinopr (int op) {
switch (op) {
case '+': return OPR_ADD;
case '-': return OPR_SUB;
case '*': return OPR_MUL;
case '/': return OPR_DIV;
case '%': return OPR_MOD;
#if LUA_BITFIELD_OPS
case '&': return OPR_BAND;
case '|': return OPR_BOR;
case TK_XOR: return OPR_BXOR;
case TK_SHL: return OPR_BSHL;
case TK_SHR: return OPR_BSHR;
#endif /* LUA_BITFIELD_OPS */
case '^': return OPR_POW;
case TK_CONCAT: return OPR_CONCAT;
case TK_NE: return OPR_NE;
case TK_EQ: return OPR_EQ;
case '<': return OPR_LT;
case TK_LE: return OPR_LE;
case '>': return OPR_GT;
case TK_GE: return OPR_GE;
case TK_AND: return OPR_AND;
case TK_OR: return OPR_OR;
default: return OPR_NOBINOPR;
}
}
static const struct {
lu_byte left; /* left priority for each binary operator */
lu_byte right; /* right priority */
} priority[] = { /* ORDER OPR */
#if LUA_BITFIELD_OPS
{8, 8}, {8, 8}, {8, 8}, {8, 8}, {8, 8}, /* bitwise operators */
#endif /* LUA_BITFIELD_OPS */
{6, 6}, {6, 6}, {7, 7}, {7, 7}, {7, 7}, /* `+' `-' `/' `%' */
{10, 9}, {5, 4}, /* power and concat (right associative) */
{3, 3}, {3, 3}, /* equality and inequality */
{3, 3}, {3, 3}, {3, 3}, {3, 3}, /* order */
{2, 2}, {1, 1} /* logical (and/or) */
};
#define UNARY_PRIORITY 8 /* priority for unary operators */
/*
** subexpr -> (simpleexp | unop subexpr) { binop subexpr }
** where `binop' is any binary operator with a priority higher than `limit'
*/
static BinOpr subexpr (LexState *ls, expdesc *v, unsigned int limit) {
BinOpr op;
UnOpr uop;
enterlevel(ls);
uop = getunopr(ls->t.token);
if (uop != OPR_NOUNOPR) {
luaX_next(ls);
subexpr(ls, v, UNARY_PRIORITY);
luaK_prefix(ls->fs, uop, v);
}
else simpleexp(ls, v);
/* expand while operators have priorities higher than `limit' */
op = getbinopr(ls->t.token);
while (op != OPR_NOBINOPR && priority[op].left > limit) {
expdesc v2;
BinOpr nextop;
luaX_next(ls);
luaK_infix(ls->fs, op, v);
/* read sub-expression with higher priority */
nextop = subexpr(ls, &v2, priority[op].right);
luaK_posfix(ls->fs, op, v, &v2);
op = nextop;
}
leavelevel(ls);
return op; /* return first untreated operator */
}
