commit 40f4e931f317f56725cba0b61ed82c0688a821f6
parent 29371ecfe87d546b9ffab480808640bd2ef226a1
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 14 Feb 2001 15:19:06 -0200
more liberal syntax for expressions
Diffstat:
| M | lparser.c | | | 151 | +++++++++++++++++++++++++++++++++++++------------------------------------------ |
1 file changed, 70 insertions(+), 81 deletions(-)
diff --git a/lparser.c b/lparser.c
@@ -1,5 +1,5 @@
/*
-** $Id: lparser.c,v 1.131 2001/02/09 18:37:33 roberto Exp roberto $
+** $Id: lparser.c,v 1.132 2001/02/09 20:22:29 roberto Exp roberto $
** LL(1) Parser and code generator for Lua
** See Copyright Notice in lua.h
*/
@@ -352,7 +352,7 @@ static void close_func (LexState *ls) {
luaM_reallocvector(L, f->lineinfo, f->sizelineinfo, fs->nlineinfo+1, int);
f->lineinfo[fs->nlineinfo++] = MAX_INT; /* end flag */
f->sizelineinfo = fs->nlineinfo;
- lua_assert(luaG_checkcode(f));
+ lua_assert(luaG_checkcode(L, f));
ls->fs = fs->prev;
lua_assert(fs->bl == NULL);
}
@@ -433,60 +433,6 @@ static void funcargs (LexState *ls, int slf) {
}
-static void var_or_func_tail (LexState *ls, expdesc *v) {
- for (;;) {
- switch (ls->t.token) {
- case '.': { /* var_or_func_tail -> '.' NAME */
- next(ls);
- luaK_tostack(ls, v, 1); /* `v' must be on stack */
- luaK_kstr(ls, checkname(ls));
- v->k = VINDEXED;
- break;
- }
- case '[': { /* var_or_func_tail -> '[' exp1 ']' */
- next(ls);
- luaK_tostack(ls, v, 1); /* `v' must be on stack */
- v->k = VINDEXED;
- exp1(ls);
- check(ls, ']');
- break;
- }
- case ':': { /* var_or_func_tail -> ':' NAME funcargs */
- next(ls);
- luaK_tostack(ls, v, 1); /* `v' must be on stack */
- luaK_code1(ls->fs, OP_PUSHSELF, checkname(ls));
- funcargs(ls, 1);
- v->k = VEXP;
- v->u.l.t = v->u.l.f = NO_JUMP;
- break;
- }
- case '(': case TK_STRING: case '{': { /* var_or_func_tail -> funcargs */
- luaK_tostack(ls, v, 1); /* `v' must be on stack */
- funcargs(ls, 0);
- v->k = VEXP;
- v->u.l.t = v->u.l.f = NO_JUMP;
- break;
- }
- default: return; /* should be follow... */
- }
- }
-}
-
-
-static void var_or_func (LexState *ls, expdesc *v) {
- /* var_or_func -> ['%'] NAME var_or_func_tail */
- if (optional(ls, '%')) { /* upvalue? */
- pushupvalue(ls, str_checkname(ls));
- v->k = VEXP;
- v->u.l.t = v->u.l.f = NO_JUMP;
- }
- else /* variable name */
- singlevar(ls, str_checkname(ls), v);
- var_or_func_tail(ls, v);
-}
-
-
-
/*
** {======================================================================
** Rules for Constructors
@@ -615,47 +561,51 @@ static void constructor (LexState *ls) {
** =======================================================================
*/
-
-static void simpleexp (LexState *ls, expdesc *v) {
+static void primaryexp (LexState *ls, expdesc *v) {
FuncState *fs = ls->fs;
switch (ls->t.token) {
- case TK_NUMBER: { /* simpleexp -> NUMBER */
+ case TK_NUMBER: {
lua_Number r = ls->t.seminfo.r;
next(ls);
luaK_number(fs, r);
break;
}
- case TK_STRING: { /* simpleexp -> STRING */
+ case TK_STRING: {
code_string(ls, ls->t.seminfo.ts); /* must use `seminfo' before `next' */
next(ls);
break;
}
- case TK_NIL: { /* simpleexp -> NIL */
+ case TK_NIL: {
luaK_adjuststack(fs, -1);
next(ls);
break;
}
- case '{': { /* simpleexp -> constructor */
+ case '{': { /* constructor */
constructor(ls);
break;
}
- case TK_FUNCTION: { /* simpleexp -> FUNCTION body */
+ case TK_FUNCTION: {
next(ls);
body(ls, 0, ls->linenumber);
break;
}
- case '(': { /* simpleexp -> '(' expr ')' */
+ case '(': {
next(ls);
expr(ls, v);
check(ls, ')');
return;
}
- case TK_NAME: case '%': {
- var_or_func(ls, v);
+ case TK_NAME: {
+ singlevar(ls, str_checkname(ls), v);
return;
}
+ case '%': {
+ next(ls); /* skip `%' */
+ pushupvalue(ls, str_checkname(ls));
+ break;
+ }
default: {
- luaK_error(ls, "<expression> expected");
+ luaK_error(ls, "unexpected symbol");
return;
}
}
@@ -664,10 +614,46 @@ static void simpleexp (LexState *ls, expdesc *v) {
}
-static void exp1 (LexState *ls) {
- expdesc v;
- expr(ls, &v);
- luaK_tostack(ls, &v, 1);
+static void simpleexp (LexState *ls, expdesc *v) {
+ /* simpleexp ->
+ primaryexp { '.' NAME | '[' exp ']' | ':' NAME funcargs | funcargs } */
+ primaryexp(ls, v);
+ for (;;) {
+ switch (ls->t.token) {
+ case '.': { /* '.' NAME */
+ next(ls);
+ luaK_tostack(ls, v, 1); /* `v' must be on stack */
+ luaK_kstr(ls, checkname(ls));
+ v->k = VINDEXED;
+ break;
+ }
+ case '[': { /* '[' exp1 ']' */
+ next(ls);
+ luaK_tostack(ls, v, 1); /* `v' must be on stack */
+ v->k = VINDEXED;
+ exp1(ls);
+ check(ls, ']');
+ break;
+ }
+ case ':': { /* ':' NAME funcargs */
+ next(ls);
+ luaK_tostack(ls, v, 1); /* `v' must be on stack */
+ luaK_code1(ls->fs, OP_PUSHSELF, checkname(ls));
+ funcargs(ls, 1);
+ v->k = VEXP;
+ v->u.l.t = v->u.l.f = NO_JUMP;
+ break;
+ }
+ case '(': case TK_STRING: case '{': { /* funcargs */
+ luaK_tostack(ls, v, 1); /* `v' must be on stack */
+ funcargs(ls, 0);
+ v->k = VEXP;
+ v->u.l.t = v->u.l.f = NO_JUMP;
+ break;
+ }
+ default: return; /* should be follow... */
+ }
+ }
}
@@ -748,6 +734,13 @@ static void expr (LexState *ls, expdesc *v) {
subexpr(ls, v, -1);
}
+
+static void exp1 (LexState *ls) {
+ expdesc v;
+ expr(ls, &v);
+ luaK_tostack(ls, &v, 1);
+}
+
/* }==================================================================== */
@@ -781,10 +774,10 @@ static void block (LexState *ls) {
static int assignment (LexState *ls, expdesc *v, int nvars) {
int left = 0; /* number of values left in the stack after assignment */
luaX_checklimit(ls, nvars, MAXVARSLH, "variables in a multiple assignment");
- if (ls->t.token == ',') { /* assignment -> ',' NAME assignment */
+ if (ls->t.token == ',') { /* assignment -> ',' simpleexp assignment */
expdesc nv;
next(ls);
- var_or_func(ls, &nv);
+ simpleexp(ls, &nv);
check_condition(ls, (nv.k != VEXP), "syntax error");
left = assignment(ls, &nv, nvars+1);
}
@@ -998,15 +991,15 @@ static void funcstat (LexState *ls, int line) {
static void namestat (LexState *ls) {
- /* stat -> func | ['%'] NAME assignment */
+ /* stat -> func | assignment */
FuncState *fs = ls->fs;
expdesc v;
- var_or_func(ls, &v);
+ simpleexp(ls, &v);
if (v.k == VEXP) { /* stat -> func */
check_condition(ls, luaK_lastisopen(fs), "syntax error"); /* an upvalue? */
luaK_setcallreturns(fs, 0); /* call statement uses no results */
}
- else { /* stat -> ['%'] NAME assignment */
+ else { /* stat -> assignment */
int left = assignment(ls, &v, 1);
luaK_adjuststack(fs, left); /* remove eventual garbage left on stack */
}
@@ -1072,10 +1065,6 @@ static int stat (LexState *ls) {
localstat(ls);
return 0;
}
- case TK_NAME: case '%': { /* stat -> namestat */
- namestat(ls);
- return 0;
- }
case TK_RETURN: { /* stat -> retstat */
retstat(ls);
return 1; /* must be last statement */
@@ -1085,7 +1074,7 @@ static int stat (LexState *ls) {
return 1; /* must be last statement */
}
default: {
- luaK_error(ls, "<statement> expected");
+ namestat(ls);
return 0; /* to avoid warnings */
}
}
