[PATCH 1/3] Extended ksh compatibility: namespace parameter syntax

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

The attached patch enables assignment of and reference to parameters
prefixed with ksh-style namespace syntax, e.g., ${.namespace.param}.
As yet, there's no special significance to use of this syntax, that
is, parameters having such a prefix are ordinary parameters like any
others, with the usual dynamic scoping rules, etc.  Each of namespace
and param must be an identifier in the original zsh semantics of
identifiers.

The braces are required when using this syntax in a parameter
substitution, so without braces $foo.bar continues to be interpreted
as ${foo}.bar.

diff --git a/Src/Zle/compcore.c b/Src/Zle/compcore.c
index 64a860fa3..77fce66e8 100644
--- a/Src/Zle/compcore.c
+++ b/Src/Zle/compcore.c
@@ -1230,14 +1230,14 @@ check_param(char *s, int set, int test)
 	else if (idigit(*e))
 	    while (idigit(*e))
 		e++;
-	else if ((ie = itype_end(e, IIDENT, 0)) != e) {
+	else if ((ie = itype_end(e, INAMESPC, 0)) != e) {
 	    do {
 		e = ie;
 		if (comppatmatch && *comppatmatch &&
 		    (*e == Star || *e == Quest))
 		    ie = e + 1;
 		else
-		    ie = itype_end(e, IIDENT, 0);
+		    ie = itype_end(e, INAMESPC, 0);
 	    } while (ie != e);
 	}
 
diff --git a/Src/Zle/zle_tricky.c b/Src/Zle/zle_tricky.c
index 07fac7144..690cf6efb 100644
--- a/Src/Zle/zle_tricky.c
+++ b/Src/Zle/zle_tricky.c
@@ -576,7 +576,7 @@ parambeg(char *s)
 	    while (idigit(*e))
 		e++;
 	else
-	    e = itype_end(e, IIDENT, 0);
+	    e = itype_end(e, INAMESPC, 0);
 
 	/* Now make sure that the cursor is inside the name. */
 	if (offs <= e - s && offs >= b - s && n <= 0) {
@@ -765,7 +765,7 @@ docomplete(int lst)
 			    else if (idigit(*q))
 				do q++; while (idigit(*q));
 			    else
-				q = itype_end(q, IIDENT, 0);
+				q = itype_end(q, INAMESPC, 0);
 			    sav = *q;
 			    *q = '\0';
 			    if (zlemetacs - wb == q - s &&
@@ -1497,7 +1497,7 @@ get_comp_string(void)
 	if (varq)
 	    tt = clwords[clwpos];
 
-	s = itype_end(tt, IIDENT, 0);
+	s = itype_end(tt, INAMESPC, 0);
 	sav = *s;
 	*s = '\0';
 	zsfree(varname);
diff --git a/Src/lex.c b/Src/lex.c
index 15da85a93..2f7937410 100644
--- a/Src/lex.c
+++ b/Src/lex.c
@@ -1230,7 +1230,7 @@ gettokstr(int c, int sub)
 		    else {
 			int sav = *lexbuf.ptr;
 			*lexbuf.ptr = '\0';
-			t = itype_end(t, IIDENT, 0);
+			t = itype_end(t, INAMESPC, 0);
 			if (t < lexbuf.ptr) {
 			    skipparens(Inbrack, Outbrack, &t);
 			} else {
diff --git a/Src/params.c b/Src/params.c
index 90302b1b0..d3b6a7d43 100644
--- a/Src/params.c
+++ b/Src/params.c
@@ -1223,7 +1223,7 @@ isident(char *s)
 		break;
     } else {
 	/* Find the first character in `s' not in the iident type table */
-	ss = itype_end(s, IIDENT, 0);
+	ss = itype_end(s, INAMESPC, 0);
     }
 
     /* If the next character is not [, then it is *
@@ -2086,6 +2086,7 @@ fetchvalue(Value v, char **pptr, int bracks, int flags)
     char *s, *t, *ie;
     char sav, c;
     int ppar = 0;
+    int itype = (flags & SCANPM_NONAMESPC) ? IIDENT : INAMESPC;
 
     s = t = *pptr;
 
@@ -2095,7 +2096,7 @@ fetchvalue(Value v, char **pptr, int bracks, int flags)
 	else
 	    ppar = *s++ - '0';
     }
-    else if ((ie = itype_end(s, IIDENT, 0)) != s)
+    else if ((ie = itype_end(s, itype, 0)) != s)
 	s = ie;
     else if (c == Quest)
 	*s++ = '?';
@@ -2183,7 +2184,7 @@ fetchvalue(Value v, char **pptr, int bracks, int flags)
 		return v;
 	    }
 	} else if (!(flags & SCANPM_ASSIGNING) && v->isarr &&
-		   itype_end(t, IIDENT, 1) != t && isset(KSHARRAYS))
+		   itype_end(t, INAMESPC, 1) != t && isset(KSHARRAYS))
 	    v->end = 1, v->isarr = 0;
     }
     if (!bracks && *s)
@@ -6196,7 +6197,7 @@ setscope(Param pm)
     if (pm->node.flags & PM_NAMEREF) {
 	Param basepm;
 	struct asgment stop;
-	char *t = pm->u.str ? itype_end(pm->u.str, IIDENT, 0) : NULL;
+	char *t = pm->u.str ? itype_end(pm->u.str, INAMESPC, 0) : NULL;
 
 	/* Temporarily change nameref to array parameter itself */
 	if (t && *t == '[')
@@ -6277,7 +6278,7 @@ upscope(Param pm, int reflevel)
 mod_export int
 valid_refname(char *val)
 {
-    char *t = itype_end(val, IIDENT, 0);
+    char *t = itype_end(val, INAMESPC, 0);
 
     if (*t != 0) {
 	if (*t == '[') {
diff --git a/Src/subst.c b/Src/subst.c
index 05bfcc03b..7a4b433bc 100644
--- a/Src/subst.c
+++ b/Src/subst.c
@@ -1870,7 +1870,7 @@ paramsubst(LinkList l, LinkNode n, char **str, int qt, int pf_flags,
      * these later on, too.
      */
     c = *s;
-    if (itype_end(s, IIDENT, 1) == s && *s != '#' && c != Pound &&
+    if (itype_end(s, INAMESPC, 1) == s && *s != '#' && c != Pound &&
 	!IS_DASH(c) &&
 	c != '!' && c != '$' && c != String && c != Qstring &&
 	c != '?' && c != Quest &&
@@ -2332,7 +2332,7 @@ paramsubst(LinkList l, LinkNode n, char **str, int qt, int pf_flags,
 	    }
 	} else if ((c == '#' || c == Pound) &&
 		   (inbrace || !isset(POSIXIDENTIFIERS)) &&
-		   (itype_end(s+1, IIDENT, 0) != s + 1
+		   (itype_end(s+1, INAMESPC, 0) != s + 1
 		    || (cc = s[1]) == '*' || cc == Star || cc == '@'
 		    || cc == '?' || cc == Quest
 		    || cc == '$' || cc == String || cc == Qstring
@@ -2369,8 +2369,9 @@ paramsubst(LinkList l, LinkNode n, char **str, int qt, int pf_flags,
 	     * Try to handle this when parameter is named
 	     * by (P) (second part of test).
 	     */
-	    if (itype_end(s+1, IIDENT, 0) != s+1 || (aspar && isstring(s[1]) &&
-				 (s[2] == Inbrace || s[2] == Inpar)))
+	    if (itype_end(s+1, INAMESPC, 0) != s+1 ||
+		(aspar && isstring(s[1]) &&
+		 (s[2] == Inbrace || s[2] == Inpar)))
 		chkset = 1, s++;
 	    else if (!inbrace) {
 		/* Special case for `$+' on its own --- leave unmodified */
@@ -2531,6 +2532,8 @@ paramsubst(LinkList l, LinkNode n, char **str, int qt, int pf_flags,
 	    scanflags |= SCANPM_DQUOTED;
 	if (chkset)
 	    scanflags |= SCANPM_CHECKING;
+	if (!inbrace)
+	    scanflags |= SCANPM_NONAMESPC;
 	/*
 	 * Second argument: decide whether to use the subexpression or
 	 *   the string next on the line as the parameter name.
@@ -3211,7 +3214,7 @@ paramsubst(LinkList l, LinkNode n, char **str, int qt, int pf_flags,
 	    shortest = 0;
 	    ++s;
 	}
-	if (*itype_end(s, IIDENT, 0)) {
+	if (*itype_end(s, INAMESPC, 0)) {
 	    untokenize(s);
 	    zerr("not an identifier: %s", s);
 	    return NULL;
@@ -3271,7 +3274,7 @@ paramsubst(LinkList l, LinkNode n, char **str, int qt, int pf_flags,
 	int intersect = (*s == '*' || *s == Star);
 	char **compare, **ap, **apsrc;
 	++s;
-	if (*itype_end(s, IIDENT, 0)) {
+	if (*itype_end(s, INAMESPC, 0)) {
 	    untokenize(s);
 	    zerr("not an identifier: %s", s);
 	    return NULL;
diff --git a/Src/utils.c b/Src/utils.c
index 55f2d1ab0..1393ecb13 100644
--- a/Src/utils.c
+++ b/Src/utils.c
@@ -3123,7 +3123,7 @@ spckword(char **s, int hist, int cmd, int ask)
 
     if (**s == String && !*t) {
 	guess = *s + 1;
-	if (itype_end(guess, IIDENT, 1) == guess)
+	if (itype_end(guess, INAMESPC, 1) == guess)
 	    return;
 	ic = String;
 	d = 100;
@@ -4310,13 +4310,27 @@ wcsitype(wchar_t c, int itype)
  * If "once" is set, just test the first character, i.e. (outptr !=
  * inptr) tests whether the first character is valid in an identifier.
  *
- * Currently this is only called with itype IIDENT, IUSER or ISEP.
+ * Currently called only with itype INAMESPC, IIDENT, IUSER or ISEP.
  */
 
 /**/
 mod_export char *
 itype_end(const char *ptr, int itype, int once)
 {
+    if (itype == INAMESPC) {
+	itype = IIDENT;
+	if (once == 0 && !isset(POSIXIDENTIFIERS)) {
+	    /* Special case for names containing ".", ksh93 namespaces */
+	    char *t = itype_end(ptr + (*ptr == '.'), itype, 0);
+	    if (t > ptr+1) {
+		if (*t == '.')
+		    return itype_end(t+1, itype, 0);
+		else
+		    return t;
+	    }
+	}
+    }
+
 #ifdef MULTIBYTE_SUPPORT
     if (isset(MULTIBYTE) &&
 	(itype != IIDENT || !isset(POSIXIDENTIFIERS))) {
diff --git a/Src/zsh.h b/Src/zsh.h
index 96b4b06bd..0de1f7afb 100644
--- a/Src/zsh.h
+++ b/Src/zsh.h
@@ -1963,6 +1963,8 @@ struct tieddata {
 				  */
 #define SCANPM_CHECKING   (1<<10) /* Check if set, no need to create */
 #define SCANPM_NOEXEC     (1<<11) /* No command substitutions, etc. */
+#define SCANPM_NONAMESPC  (1<<12) /* namespace syntax not allowed */
+
 /* "$foo[@]"-style substitution
  * Only sign bit is significant
  */
diff --git a/Src/ztype.h b/Src/ztype.h
index 8757fc733..4675f73a9 100644
--- a/Src/ztype.h
+++ b/Src/ztype.h
@@ -43,6 +43,7 @@
 #define IWSEP    (1 << 13)
 #define INULL    (1 << 14)
 #define IPATTERN (1 << 15)
+#define INAMESPC (1 << 16)
 #define zistype(X,Y) (typtab[(unsigned char) (X)] & Y)
 #define idigit(X) zistype(X,IDIGIT)
 #define ialnum(X) zistype(X,IALNUM)