Fixing bug in foldr

examples/example.sh

@@ -55,3 +55,6 @@ function add() {
 
 curry add3 add 3
 add3 9
+
+list a b c d | foldl lambda acc el . 'echo -n $acc-$el'
+list '' a b c d | foldr lambda acc el . 'if [[ ! -z $acc ]]; then echo -n $acc-$el; else echo -n $el; fi'

src/fun.sh

@@ -85,11 +85,18 @@ foldl() {
 foldr() {
   local f="$@"
   local acc
-  read acc
+  local zero
-
+  read zero
   foldrr() {
     local elem
-    read elem && acc=$(foldrr)
+
+    if read elem; then
+        acc=$(foldrr)
+#        [[ -z $acc ]] && echo $elem && return
+    else
+        echo $zero && return
+    fi
+
     acc="$({ echo $acc; echo $elem; } | $f )"
     echo "$acc"
   }