confz

commit 07a98ca766aedbddf2984e54e8b06ae94b81d5fe
parent 81e681c48ac8bb8f15fef0f5ff693a23de3a956c
Author: Jan Pobrislo <ccx@webprojekty.cz>
Date:   Thu, 26 Jun 2014 21:27:11 +0200

conditional variable passing, error out gracefully on undefined variables
Diffstat:
M
bin/confz
 | 
13
++++++++++++-

1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/bin/confz b/bin/confz
@@ -96,6 +96,10 @@ require() {
 	#   <variables> are variable assignments in the form of:
 	#       foo=bar  -- sets ${vars[foo]} in calee to value "bar"
 	#       :foo  -- passes ${vars[foo]} from caller to calee
+	#       ?foo=bar -- sets ${vars[foo]} in calee to value of ${vars[bar]}
+	#                   iff it is defined in the caller
+	#       ?foo -- passes ${vars[foo]} from caller to calee iff it is defined
+	#               in the caller
 	#       %foo  -- passes ${vars[foo]} from callee to caller
 	#       %foo=bar  -- passes ${vars[foo]} from callee
 	#                    to variable ${vars[bar]} of caller
@@ -119,7 +123,12 @@ require() {
 	# parse variable assignments
 	while (( $# )); do
 		case $1 in
-			(:*)   setvar ${1#:} ${vars_prev[${1#:}]};;
+			(:*)   ((${+vars_prev[${1#:}]})) || \
+				die "variable ${(qqq)1#:} not set, passed as :argument"
+				setvar ${1#:} ${vars_prev[${1#:}]};;
+			(\?*=*) (($+vars_prev[${${1#\?}#*=})) && \
+				setvar ${${1#\?}%%=*} $vars_prev[${${1#\?}#*=};;
+			(\?*)  setvar ${1#\?} ${vars_prev[${1#\?}]};;
 			(%*=*) lift[${${1#%}%%=*}]=${${1#%}#*=};;
 			(%*)   lift[${1#%}]=${1#%};;
 			(*=*)  setvar ${1%%=*} ${1#*=};;
@@ -185,6 +194,8 @@ require() {
 
 	# lift %variables from calee to caller
 	for outer inner in ${(kv)lift}; do
+		((${+vars_prev[$inner]})) || \
+			die "variable ${(qqq)inner} not set, was requested by caller as ${(qqq)outer}"
 		setvar $outer ${vars_prev[$inner]}
 	done
 }