PATCH: expanding parameters like echo/print builtins

[Mikael Magnusson <mikachu@gmail.com>]

Is this already possible? I had an array with a lot of \u1234 escapes
in it, and couldn't find a way to do it easily. I came up with this:
${arr:gs/(#b)'\\\\u(????)/${(#):-$(( 16#$match[1] ))}'}
but it's a bit awkward to type.

The following patch adds the (g::) parameter flag which calls the
getkeystring function, and allows setting the _EMACS, _OCTAL_ESC and
_CTRL flags.

---
 Doc/Zsh/expn.yo |    8 ++++++++
 Src/subst.c     |   55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 63 insertions(+), 0 deletions(-)

diff --git a/Doc/Zsh/expn.yo b/Doc/Zsh/expn.yo
index 2c3a571..2beebd7 100644
--- a/Doc/Zsh/expn.yo
+++ b/Doc/Zsh/expn.yo
@@ -863,6 +863,14 @@ item(tt(F))(
 Join the words of arrays together using newline as a separator.
 This is a shorthand for `tt(pj:\n:)'.
 )
+item(tt(g:opts:))(
+Expand words like the echo builtin.  With the tt(o) option, octal escapes
+don't take a leading zero.  With the tt(c) option, sequences like `tt(^X)'
+are interpreted.  With the tt(e) option, interprets `tt(\M-t)' and similar
+sequences like the print builtin.  With both tt(o) and tt(e) options, behaves
+like the print builtin with the exception of the next sentence.   In none
+of these modes is `tt(\c)' interpreted.
+)
 item(tt(i))(
 Sort case-insensitively.  May be combined with `tt(n)' or `tt(O)'.
 )
diff --git a/Src/subst.c b/Src/subst.c
index 617986c..a2af01b 100644
--- a/Src/subst.c
+++ b/Src/subst.c
@@ -1607,6 +1607,10 @@ paramsubst(LinkList l, LinkNode n, char **str, int qt, int ssub)
      */	
     int presc = 0;
     /*
+     * The (g) flag.  Expand words with various GETKEY_ flags.
+     */
+    int getkeys = -1;
+    /*
      * The (@) flag; interacts obscurely with qt and isarr.
      * This is one of the things that decides whether multsub
      * will produce an array, but in an extremely indirect fashion.
@@ -1932,6 +1936,36 @@ paramsubst(LinkList l, LinkNode n, char **str, int qt, int ssub)
 		    presc++;
 		    break;
 
+		case 'z':
+		    t = get_strarg(++s, &arglen);
+		    if (getkeys < 0)
+			getkeys = 0;
+		    if (*t) {
+			sav = *t;
+			*t = 0;
+			while (*++s) {
+			    switch (*s) {
+			    case 'e':
+				getkeys |= GETKEY_EMACS;
+				break;
+			    case 'o':
+				getkeys |= GETKEY_OCTAL_ESC;
+				break;
+			    case 'c':
+				getkeys |= GETKEY_CTRL;
+				break;
+
+			    default:
+				*t = sav;
+				goto flagerr;
+			    }
+			}
+			*t = sav;
+			s = t + arglen - 1;
+		    } else
+			goto flagerr;
+                    break;
+
 		case 'z':
 		    shsplit = LEXFLAGS_ACTIVE;
 		    break;
@@ -3141,6 +3175,27 @@ paramsubst(LinkList l, LinkNode n, char **str, int qt, int ssub)
 	opts[PROMPTPERCENT] = opp;
     }
     /*
+     * Perform GETKEY expansion
+     */
+    if (getkeys >= 0) {
+	if (isarr) {
+	    char **ap;
+
+	    if (!copied)
+		aval = arrdup(aval), copied = 1;
+	    ap = aval;
+	    for (; *ap; ap++) {
+		int len;
+		*ap = getkeystring(*ap, &len, getkeys, NULL);
+	    }
+	} else {
+	    int len;
+	    if (!copied)
+		val = dupstring(val), copied = 1;
+	    val = getkeystring(val, &len, getkeys, NULL);
+	}
+    }
+    /*
      * One of the possible set of quotes to apply, depending on
      * the repetitions of the (q) flag.
      */
-- 
1.7.4-rc1