33423: expand ${(p)...} to allow ${(ps.$param.)...}

3 files changed, 35 insertions, 5 deletions

diff --git a/ChangeLog b/ChangeLog
index b2287d27c..e1de05210 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2014-10-12  Peter Stephenson  <p.w.stephenson@ntlworld.com>
+
+	* 33423: Doc/Zsh/expn.yo, Src/subst.c: parameter expansion
+	(p) flag allows delimited strings to contain simple $param
+	expansions.
+
 2014-10-11  Barton E. Schaefer  <schaefer@zsh.org>
 
 	* unposted: Test/B06fc.ztst: tests for 33429.
diff --git a/Doc/Zsh/expn.yo b/Doc/Zsh/expn.yo
index 5aab25954..a0478e78c 100644
--- a/Doc/Zsh/expn.yo
+++ b/Doc/Zsh/expn.yo
@@ -1124,6 +1124,19 @@ item(tt(p))(
 Recognize the same escape sequences as the tt(print) builtin
 in string arguments to any of the flags described below that
 follow this argument.
+
+Alternatively, with this option string arguments may be in the form
+tt($)var(var) in which case the value of the variable is substituted.
+Note this form is strict; the string argument does not undergo general
+parameter expansion.
+
+For example,
+
+example(sep=:
+val=a:b:c
+print ${+LPAR()ps.$sep.+RPAR()val})
+
+splits the variable on a tt(:).
 )
 item(tt(~))(
 Strings inserted into the expansion by any of the flags below are to
diff --git a/Src/subst.c b/Src/subst.c
index 1aa9b982e..61aa1c136 100644
--- a/Src/subst.c
+++ b/Src/subst.c
@@ -1385,12 +1385,23 @@ static char *
 untok_and_escape(char *s, int escapes, int tok_arg)
 {
     int klen;
-    char *dst;
+    char *dst = NULL;
 
-    untokenize(dst = dupstring(s));
-    if (escapes) {
-	dst = getkeystring(dst, &klen, GETKEYS_SEP, NULL);
-	dst = metafy(dst, klen, META_HREALLOC);
+    if (escapes && (*s == String || *s == Qstring) && s[1]) {
+	char *pstart = s+1, *pend;
+	for (pend = pstart; *pend; pend++)
+	    if (!iident(*pend))
+		break;
+	if (!*pend) {
+	    dst = dupstring(getsparam(pstart));
+	}
+    }
+    if (dst == NULL) {
+	untokenize(dst = dupstring(s));
+	if (escapes) {
+	    dst = getkeystring(dst, &klen, GETKEYS_SEP, NULL);
+	    dst = metafy(dst, klen, META_HREALLOC);
+	}
     }
     if (tok_arg)
 	shtokenize(dst);