15030: multi-parameter `for' loops

5 files changed, 85 insertions, 39 deletions

diff --git a/ChangeLog b/ChangeLog
index 3e6e2efeb..bae8ee09d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2001-06-25  Peter Stephenson  <pws@csr.com>
+
+	* 15030: Doc/Zsh/grammar.yo, Src/loop.c, Src/parse.c, Src/text.c:
+	`for' loops can take multiple parameter names before the `in'
+	or left parenthesis, each of which takes one word from the list
+	on each iteration.
+
 2001-06-25  Sven Wischnowsky  <wischnow@zsh.org>
 
 	* user/3940: Src/Zle/zle_tricky.c: make expand-word not always
diff --git a/Doc/Zsh/grammar.yo b/Doc/Zsh/grammar.yo
index df5bb8581..30ea060bd 100644
--- a/Doc/Zsh/grammar.yo
+++ b/Doc/Zsh/grammar.yo
@@ -149,12 +149,21 @@ If each tt(elif) var(list) returns nonzero, the tt(else) var(list) is executed.
 findex(for)
 cindex(for loops)
 cindex(loops, for)
-item(tt(for) var(name) [ tt(in) var(word) ... var(term) ] tt(do) var(list) tt(done))(
+item(tt(for) var(name) ... [ tt(in) var(word) ... ] var(term) tt(do) var(list) tt(done))(
 where var(term) is at least one newline or tt(;).
 Expand the list of var(word)s, and set the parameter
 var(name) to each of them in turn, executing
 var(list) each time.  If the tt(in) var(word) is omitted,
 use the positional parameters instead of the var(word)s.
+
+More than one parameter var(name) can appear before the list of
+var(word)s.  If var(N) var(name)s are given, then on each execution of the
+loop the next tt(N) var(word)s are assigned to the corresponding
+parameters.  If there are more var(name)s than remaining var(word)s, the
+remaining parameters are each set to the empty string.  Execution of the
+loop ends when there is no remaining var(word) to assign to the first
+var(name).  It is only possible for tt(in) to appear as the first var(name)
+in the list, else it will be treated as marking the end of the list.
 )
 item(tt(for LPAR()LPAR()) [var(expr1)] tt(;) [var(expr2)] tt(;) [var(expr3)] tt(RPAR()RPAR() do) var(list) tt(done))(
 The arithmetic expression var(expr1) is evaluated first (see
@@ -289,17 +298,17 @@ does em(not), since the test is not suitably delimited.
 item(tt(if) var(list) var(sublist))(
 A short form of the alternate `if'.
 )
-item(tt(for) var(name) tt(LPAR()) var(word) ... tt(RPAR()) var(sublist))(
+item(tt(for) var(name) ... tt(LPAR()) var(word) ... tt(RPAR()) var(sublist))(
 A short form of tt(for).
 )
-item(tt(for) var(name) [ tt(in) var(word) ... var(term) ] var(sublist))(
+item(tt(for) var(name) ... [ tt(in) var(word) ... ] var(term) var(sublist))(
 where var(term) is at least one newline or tt(;).
 Another short form of tt(for).
 )
 item(tt(for LPAR()LPAR()) [var(expr1)] tt(;) [var(expr2)] tt(;) [var(expr3)] tt(RPAR()RPAR()) var(sublist))(
 A short form of the arithmetic tt(for) command.
 )
-item(tt(foreach) var(name) tt(LPAR()) var(word) ... tt(RPAR()) var(list) tt(end))(
+item(tt(foreach) var(name) ... tt(LPAR()) var(word) ... tt(RPAR()) var(list) tt(end))(
 Another form of tt(for).
 )
 item(tt(while) var(list) tt({) var(list) tt(}))(
diff --git a/Src/loop.c b/Src/loop.c
index 84ac39e9a..38eeda7d6 100644
--- a/Src/loop.c
+++ b/Src/loop.c
@@ -52,15 +52,15 @@ execfor(Estate state, int do_exec)
     Wordcode end, loop;
     wordcode code = state->pc[-1];
     int iscond = (WC_FOR_TYPE(code) == WC_FOR_COND), ctok = 0, atok = 0;
+    int last = 0;
     char *name, *str, *cond = NULL, *advance = NULL;
     zlong val = 0;
-    LinkList args = NULL;
+    LinkList vars = NULL, args = NULL;
 
-    name = ecgetstr(state, EC_NODUP, NULL);
     end = state->pc + WC_FOR_SKIP(code);
 
     if (iscond) {
-	str = dupstring(name);
+	str = dupstring(ecgetstr(state, EC_NODUP, NULL));
 	singsub(&str);
 	if (isset(XTRACE)) {
 	    char *str2 = dupstring(str);
@@ -77,28 +77,32 @@ execfor(Estate state, int do_exec)
 	}
 	cond = ecgetstr(state, EC_NODUP, &ctok);
 	advance = ecgetstr(state, EC_NODUP, &atok);
-    } else if (WC_FOR_TYPE(code) == WC_FOR_LIST) {
-	int htok = 0;
-
-	if (!(args = ecgetlist(state, *state->pc++, EC_DUPTOK, &htok))) {
-	    state->pc = end;
-	    return 0;
-	}
-	if (htok)
-	    execsubst(args);
     } else {
-	char **x;
+	vars = ecgetlist(state, *state->pc++, EC_NODUP, NULL);
 
-	args = newlinklist();
-	for (x = pparams; *x; x++)
-	    addlinknode(args, dupstring(*x));
+	if (WC_FOR_TYPE(code) == WC_FOR_LIST) {
+	    int htok = 0;
+
+	    if (!(args = ecgetlist(state, *state->pc++, EC_DUPTOK, &htok))) {
+		state->pc = end;
+		return 0;
+	    }
+	    if (htok)
+		execsubst(args);
+	} else {
+	    char **x;
+
+	    args = newlinklist();
+	    for (x = pparams; *x; x++)
+		addlinknode(args, dupstring(*x));
+	}
     }
     lastval = 0;
     loops++;
     pushheap();
     cmdpush(CS_FOR);
     loop = state->pc;
-    for (;;) {
+    while (!last) {
 	if (iscond) {
 	    if (ctok) {
 		str = dupstring(cond);
@@ -127,14 +131,29 @@ execfor(Estate state, int do_exec)
 	    if (!val)
 		break;
 	} else {
-	    if (!args || !(str = (char *) ugetnode(args)))
-		break;
-	    if (isset(XTRACE)) {
-		printprompt4();
-		fprintf(xtrerr, "%s=%s\n", name, str);
-		fflush(xtrerr);
+	    LinkNode node;
+	    int count = 0;
+	    for (node = firstnode(vars); node; incnode(node))
+	    {
+		name = (char *)getdata(node);
+		if (!args || !(str = (char *) ugetnode(args)))
+		{
+		    if (count) { 
+			str = "";
+			last = 1;
+		    } else
+			break;
+		}
+		if (isset(XTRACE)) {
+		    printprompt4();
+		    fprintf(xtrerr, "%s=%s\n", name, str);
+		    fflush(xtrerr);
+		}
+		setsparam(name, ztrdup(str));
+		count++;
 	    }
-	    setsparam(name, ztrdup(str));
+	    if (!count)
+		break;
 	}
 	state->pc = loop;
 	execlist(state, 1, do_exec && args && empty(args));
diff --git a/Src/parse.c b/Src/parse.c
index b611e8e0c..fd7138605 100644
--- a/Src/parse.c
+++ b/Src/parse.c
@@ -878,7 +878,7 @@ static void
 par_for(int *complex)
 {
     int oecused = ecused, csh = (tok == FOREACH), p, sel = (tok == SELECT);
-    int type;
+    int type, ona = noaliases;
 
     p = ecadd(0);
 
@@ -903,19 +903,32 @@ par_for(int *complex)
 	yylex();
 	type = WC_FOR_COND;
     } else {
-	int posix_in;
+	int np, n, posix_in;
 	infor = 0;
 	if (tok != STRING || !isident(tokstr))
 	    YYERRORV(oecused);
-	ecstr(tokstr);
+	np = ecadd(0);
+	n = 0;
 	incmdpos = 1;
-	yylex();
+	noaliases = 1;
+	for (;;) {
+	    n++;
+	    ecstr(tokstr);
+	    yylex();	
+	    if (tok != STRING || !strcmp(tokstr, "in") || sel)
+		break;
+	    if (!isident(tokstr))
+	    {
+		noaliases = ona;
+		YYERRORV(oecused);
+	    }
+	}
+	noaliases = ona;
+	ecbuf[np] = n;
 	posix_in = isnewlin;
 	while (isnewlin)
-	  yylex();
-	if (tok == STRING && !strcmp(tokstr, "in")) {
-	    int np, n;
-
+	    yylex();
+        if (tok == STRING && !strcmp(tokstr, "in")) {
 	    incmdpos = 0;
 	    yylex();
 	    np = ecadd(0);
@@ -925,8 +938,6 @@ par_for(int *complex)
 	    ecbuf[np] = n;
 	    type = (sel ? WC_SELECT_LIST : WC_FOR_LIST);
 	} else if (!posix_in && tok == INPAR) {
-	    int np, n;
-
 	    incmdpos = 0;
 	    yylex();
 	    np = ecadd(0);
diff --git a/Src/text.c b/Src/text.c
index 27d16d378..7595c9add 100644
--- a/Src/text.c
+++ b/Src/text.c
@@ -415,7 +415,7 @@ gettext2(Estate state)
 		    taddstr(ecgetstr(state, EC_NODUP, NULL));
 		    taddstr(")) do");
 		} else {
-		    taddstr(ecgetstr(state, EC_NODUP, NULL));
+		    taddlist(state, *state->pc++);
 		    if (WC_FOR_TYPE(code) == WC_FOR_LIST) {
 			taddstr(" in ");
 			taddlist(state, *state->pc++);