mirror of https://github.com/lua/lua
more liberal syntax for expressions
This commit is contained in:
Roberto Ierusalimschy
parent
29371ecfe8
commit
40f4e931f3
151
lparser.c
151
lparser.c
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@ -1,5 +1,5 @@
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/*
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** $Id: lparser.c,v 1.131 2001/02/09 18:37:33 roberto Exp roberto $
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** $Id: lparser.c,v 1.132 2001/02/09 20:22:29 roberto Exp roberto $
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** LL(1) Parser and code generator for Lua
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** See Copyright Notice in lua.h
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*/
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@ -352,7 +352,7 @@ static void close_func (LexState *ls) {
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luaM_reallocvector(L, f->lineinfo, f->sizelineinfo, fs->nlineinfo+1, int);
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f->lineinfo[fs->nlineinfo++] = MAX_INT; /* end flag */
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f->sizelineinfo = fs->nlineinfo;
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lua_assert(luaG_checkcode(f));
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lua_assert(luaG_checkcode(L, f));
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ls->fs = fs->prev;
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lua_assert(fs->bl == NULL);
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}
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@ -433,60 +433,6 @@ static void funcargs (LexState *ls, int slf) {
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}
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static void var_or_func_tail (LexState *ls, expdesc *v) {
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for (;;) {
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switch (ls->t.token) {
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case '.': { /* var_or_func_tail -> '.' NAME */
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next(ls);
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luaK_tostack(ls, v, 1); /* `v' must be on stack */
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luaK_kstr(ls, checkname(ls));
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v->k = VINDEXED;
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break;
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}
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case '[': { /* var_or_func_tail -> '[' exp1 ']' */
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next(ls);
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luaK_tostack(ls, v, 1); /* `v' must be on stack */
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v->k = VINDEXED;
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exp1(ls);
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check(ls, ']');
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break;
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}
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case ':': { /* var_or_func_tail -> ':' NAME funcargs */
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next(ls);
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luaK_tostack(ls, v, 1); /* `v' must be on stack */
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luaK_code1(ls->fs, OP_PUSHSELF, checkname(ls));
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funcargs(ls, 1);
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v->k = VEXP;
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v->u.l.t = v->u.l.f = NO_JUMP;
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break;
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}
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case '(': case TK_STRING: case '{': { /* var_or_func_tail -> funcargs */
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luaK_tostack(ls, v, 1); /* `v' must be on stack */
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funcargs(ls, 0);
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v->k = VEXP;
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v->u.l.t = v->u.l.f = NO_JUMP;
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break;
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}
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default: return; /* should be follow... */
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}
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}
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}
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static void var_or_func (LexState *ls, expdesc *v) {
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/* var_or_func -> ['%'] NAME var_or_func_tail */
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if (optional(ls, '%')) { /* upvalue? */
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pushupvalue(ls, str_checkname(ls));
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v->k = VEXP;
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v->u.l.t = v->u.l.f = NO_JUMP;
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}
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else /* variable name */
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singlevar(ls, str_checkname(ls), v);
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var_or_func_tail(ls, v);
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}
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/*
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** {======================================================================
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** Rules for Constructors
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@ -615,47 +561,51 @@ static void constructor (LexState *ls) {
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** =======================================================================
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*/
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static void simpleexp (LexState *ls, expdesc *v) {
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static void primaryexp (LexState *ls, expdesc *v) {
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FuncState *fs = ls->fs;
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switch (ls->t.token) {
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case TK_NUMBER: { /* simpleexp -> NUMBER */
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case TK_NUMBER: {
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lua_Number r = ls->t.seminfo.r;
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next(ls);
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luaK_number(fs, r);
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break;
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}
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case TK_STRING: { /* simpleexp -> STRING */
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case TK_STRING: {
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code_string(ls, ls->t.seminfo.ts); /* must use `seminfo' before `next' */
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next(ls);
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break;
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}
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case TK_NIL: { /* simpleexp -> NIL */
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case TK_NIL: {
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luaK_adjuststack(fs, -1);
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next(ls);
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break;
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}
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case '{': { /* simpleexp -> constructor */
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case '{': { /* constructor */
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constructor(ls);
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break;
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}
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case TK_FUNCTION: { /* simpleexp -> FUNCTION body */
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case TK_FUNCTION: {
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next(ls);
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body(ls, 0, ls->linenumber);
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break;
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}
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case '(': { /* simpleexp -> '(' expr ')' */
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case '(': {
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next(ls);
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expr(ls, v);
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check(ls, ')');
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return;
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}
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case TK_NAME: case '%': {
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var_or_func(ls, v);
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case TK_NAME: {
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singlevar(ls, str_checkname(ls), v);
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return;
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}
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case '%': {
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next(ls); /* skip `%' */
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pushupvalue(ls, str_checkname(ls));
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break;
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}
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default: {
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luaK_error(ls, "<expression> expected");
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luaK_error(ls, "unexpected symbol");
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return;
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}
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}
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@ -664,10 +614,46 @@ static void simpleexp (LexState *ls, expdesc *v) {
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}
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static void exp1 (LexState *ls) {
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expdesc v;
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expr(ls, &v);
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luaK_tostack(ls, &v, 1);
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static void simpleexp (LexState *ls, expdesc *v) {
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/* simpleexp ->
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primaryexp { '.' NAME | '[' exp ']' | ':' NAME funcargs | funcargs } */
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primaryexp(ls, v);
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for (;;) {
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switch (ls->t.token) {
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case '.': { /* '.' NAME */
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next(ls);
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luaK_tostack(ls, v, 1); /* `v' must be on stack */
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luaK_kstr(ls, checkname(ls));
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v->k = VINDEXED;
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break;
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}
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case '[': { /* '[' exp1 ']' */
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next(ls);
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luaK_tostack(ls, v, 1); /* `v' must be on stack */
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v->k = VINDEXED;
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exp1(ls);
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check(ls, ']');
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break;
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}
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case ':': { /* ':' NAME funcargs */
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next(ls);
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luaK_tostack(ls, v, 1); /* `v' must be on stack */
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luaK_code1(ls->fs, OP_PUSHSELF, checkname(ls));
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funcargs(ls, 1);
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v->k = VEXP;
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v->u.l.t = v->u.l.f = NO_JUMP;
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break;
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}
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case '(': case TK_STRING: case '{': { /* funcargs */
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luaK_tostack(ls, v, 1); /* `v' must be on stack */
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funcargs(ls, 0);
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v->k = VEXP;
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v->u.l.t = v->u.l.f = NO_JUMP;
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break;
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}
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default: return; /* should be follow... */
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}
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}
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}
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@ -748,6 +734,13 @@ static void expr (LexState *ls, expdesc *v) {
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subexpr(ls, v, -1);
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}
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static void exp1 (LexState *ls) {
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expdesc v;
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expr(ls, &v);
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luaK_tostack(ls, &v, 1);
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}
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/* }==================================================================== */
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@ -781,10 +774,10 @@ static void block (LexState *ls) {
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static int assignment (LexState *ls, expdesc *v, int nvars) {
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int left = 0; /* number of values left in the stack after assignment */
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luaX_checklimit(ls, nvars, MAXVARSLH, "variables in a multiple assignment");
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if (ls->t.token == ',') { /* assignment -> ',' NAME assignment */
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if (ls->t.token == ',') { /* assignment -> ',' simpleexp assignment */
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expdesc nv;
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next(ls);
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var_or_func(ls, &nv);
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simpleexp(ls, &nv);
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check_condition(ls, (nv.k != VEXP), "syntax error");
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left = assignment(ls, &nv, nvars+1);
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}
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@ -998,15 +991,15 @@ static void funcstat (LexState *ls, int line) {
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static void namestat (LexState *ls) {
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/* stat -> func | ['%'] NAME assignment */
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/* stat -> func | assignment */
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FuncState *fs = ls->fs;
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expdesc v;
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var_or_func(ls, &v);
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simpleexp(ls, &v);
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if (v.k == VEXP) { /* stat -> func */
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check_condition(ls, luaK_lastisopen(fs), "syntax error"); /* an upvalue? */
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luaK_setcallreturns(fs, 0); /* call statement uses no results */
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}
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else { /* stat -> ['%'] NAME assignment */
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else { /* stat -> assignment */
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int left = assignment(ls, &v, 1);
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luaK_adjuststack(fs, left); /* remove eventual garbage left on stack */
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}
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@ -1072,10 +1065,6 @@ static int stat (LexState *ls) {
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localstat(ls);
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return 0;
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}
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case TK_NAME: case '%': { /* stat -> namestat */
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namestat(ls);
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return 0;
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}
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case TK_RETURN: { /* stat -> retstat */
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retstat(ls);
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return 1; /* must be last statement */
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@ -1085,7 +1074,7 @@ static int stat (LexState *ls) {
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return 1; /* must be last statement */
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}
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default: {
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luaK_error(ls, "<statement> expected");
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namestat(ls);
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return 0; /* to avoid warnings */
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}
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}
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