From: Bart Schaefer <schaefer@brasslantern.com>
To: Zsh workers <zsh-workers@zsh.org>
Subject: [PATCH] Re: namespaces limitation
Date: Thu, 22 Jun 2023 10:49:54 -0700 [thread overview]
Message-ID: <CAH+w=7YaOUcqtigNah72PFkUxq_p0LXt=Unf62b7TL3M+OYwtw@mail.gmail.com> (raw)
In-Reply-To: <CAH+w=7YBoMrNOokZmDJJehv2oF_RUkhY=USmJFHb-A8X32LaLA@mail.gmail.com>
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On Thu, May 18, 2023 at 5:14 PM Oliver Kiddle <opk@zsh.org> wrote:
>
> integer .var.d=0
> (( .var.d++ ))
> zsh: bad floating point constant
>
> It'd be good if it could identify this as a namespace variable.
This should be correctly handled after this patch, test is included.
If you find other broken edge cases please point them out.
On Thu, May 25, 2023 at 3:09 PM Bart Schaefer <schaefer@brasslantern.com> wrote:
>
> On Wed, May 24, 2023 at 9:41 AM Oliver Kiddle <opk@zsh.org> wrote:
> >
> > integer .var=56
> >
> > would be disallowed.
>
> I had it that way at one point and backed off because ksh allows it.
Patch below leaves this unchanged (so still allowed) and adds a test for it.
> Strictly speaking (to the extent that any of this is strict),
> namespaces are supposed to otherwise obey the rules for identifiers,
> which with the exception of positional parameters are not allowed to
> begin with a digit ... so I think I'll just go with that.
>
> I still haven't worked out how to deal correctly with .var.3x
The below enforces that identifiers following a namespace prefix must
either begin with a non-digit or must consist entirely of digits. For
possible future enhancements, this does not apply when the identifier
before the first "." does not itself begin with a ".", that is,
${var.3x} is allowed.
I haven't determined how/where to document that latter special case.
Perhaps it's not necessary to do so, given that omitting the first "."
is explicitly discouraged.
> > Also questionable is the following which currently works:
> >
> > .a.=ddd
This is rejected by the patch (not an identifier / bad substitution).
I think the extra checks add very little if any overhead to the
unaffected cases but I haven't run benchmarks.
> > We also currently allow a.=ddd but I think that is less
> > questionable. We allow empty association elements.
>
> I'm still not entirely sold on the x.y <=> x[y] mapping idea, but if
> we follow JavaScript's (somewhat questionable) lead on this, empty
> elements have to use bracket-notation rather than dot-notation.
I've not [yet] enforced the bracket-notation requirement, so as a
special case of the ${var.3x} case above, ${var.} is also allowed. A
point against following JS is that JS doesn't have the braces around
the reference to delineate the empty element.
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diff --git a/Src/math.c b/Src/math.c
index 12c8d6f6b..a060181ed 100644
--- a/Src/math.c
+++ b/Src/math.c
@@ -641,7 +641,9 @@ zzlex(void)
return MINUSEQ;
}
if (unary) {
- if (idigit(*ptr) || *ptr == '.') {
+ if (idigit(*ptr) ||
+ (*ptr == '.' &&
+ (idigit(ptr[1]) || !itype_end(ptr, INAMESPC, 0)))) {
int ctype = lexconstant();
if (ctype == NUM)
{
@@ -835,7 +837,9 @@ zzlex(void)
case Dnull:
break;
default:
- if (idigit(*--ptr) || *ptr == '.')
+ if (idigit(*--ptr) ||
+ (*ptr == '.' &&
+ (idigit(ptr[1]) || !itype_end(ptr, INAMESPC, 0))))
return lexconstant();
if (*ptr == '#') {
if (*++ptr == '\\' || *ptr == '#') {
@@ -857,7 +861,7 @@ zzlex(void)
}
cct = 1;
}
- if ((ie = itype_end(ptr, IIDENT, 0)) != ptr) {
+ if ((ie = itype_end(ptr, INAMESPC, 0)) != ptr) {
int func = 0;
char *p;
diff --git a/Src/params.c b/Src/params.c
index 021d341e8..2b0837e03 100644
--- a/Src/params.c
+++ b/Src/params.c
@@ -1226,6 +1226,26 @@ isident(char *s)
if (!*s) /* empty string is definitely not valid */
return 0;
+ /* This partly duplicates code in itype_end(), but we need to
+ * distinguish the leading namespace at this point to check the
+ * correctness of the identifier that follows
+ */
+ if (*s == '.') {
+ if (idigit(s[1]))
+ return 0; /* Namespace must not start with a digit */
+ /* Reject identifiers beginning with a digit in namespaces.
+ * Move this out below this block to also reject v.1x form.
+ */
+ if ((ss = itype_end(s + (*s == '.'), IIDENT, 0))) {
+ if (*ss == '.') {
+ if (!ss[1])
+ return 0;
+ if (idigit(ss[1]))
+ s = ss + 1;
+ }
+ }
+ }
+
if (idigit(*s)) {
/* If the first character is `s' is a digit, then all must be */
for (ss = ++s; *ss; ss++)
@@ -2148,7 +2168,12 @@ fetchvalue(Value v, char **pptr, int bracks, int flags)
pm = (Param) paramtab->getnode2(paramtab, *t == '0' ? "0" : t);
else
pm = (Param) paramtab->getnode(paramtab, *t == '0' ? "0" : t);
- if (sav)
+ if (!pm && *t == '.' && !isident(t)) {
+ /* badly formed namespace reference */
+ if (sav)
+ *s = sav;
+ return NULL;
+ } else if (sav)
*s = sav;
*pptr = s;
if (!pm || ((pm->node.flags & PM_UNSET) &&
diff --git a/Test/K02parameter.ztst b/Test/K02parameter.ztst
index 8a1be1e36..0b1a8dd4a 100644
--- a/Test/K02parameter.ztst
+++ b/Test/K02parameter.ztst
@@ -100,7 +100,55 @@ F:Braces are required
>.k02.array
>characters
+ k.=empty
k.2=test
- print ${k.2}
+ print ${k.} ${k.2}
0:Parse without leading dot (future proofing)
->test
+>empty test
+
+ .k=OK
+ print ${.k}
+0:Bare namespace is usable (ksh compatibility)
+>OK
+
+ .k.=empty
+1:Namespace must precede an identifier, assignment
+?(eval):1: not an identifier: .k.
+
+ typeset .k.=empty
+1:Namespace must precede an identifier, typeset
+?(eval):typeset:1: not valid in this context: .k.
+
+ print ${.k.}
+1:Namespace must precede an identifier, reference
+?(eval):1: bad substitution
+
+ .2.b=not
+1:Namespace identifier must not begin with a digit, assignment
+?(eval):1: not an identifier: .2.b
+
+ typeset .2.b=not
+1:Namespace identifier must not begin with a digit, typeset
+?(eval):typeset:1: not valid in this context: .2.b
+
+ print ${.2.b}
+1:Namespace identifier must not begin with a digit, reference
+?(eval):1: bad substitution
+
+ .not.2b=question
+1:Identifier starting with a digit must be all digits, assignment
+?(eval):1: not an identifier: .not.2b
+
+ typeset .not.2b=question
+1:Identifier starting with a digit must be all digits, typeset
+?(eval):typeset:1: not valid in this context: .not.2b
+
+ print ${.not.2b}
+1:Identifier starting with a digit must be all digits, reference
+?(eval):1: bad substitution
+
+ integer .var.d=0
+ float .var.f=.2
+ print $((.var.x = ++.var.d - -.var.f))
+0:Namespaces in math context
+>1.2
prev parent reply other threads:[~2023-06-22 17:50 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-19 0:13 Oliver Kiddle
2023-05-23 17:10 ` Bart Schaefer
2023-05-24 16:41 ` Oliver Kiddle
2023-05-25 22:09 ` Bart Schaefer
2023-05-25 23:13 ` Bart Schaefer
2023-06-22 17:49 ` Bart Schaefer [this message]
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