diff --git a/osh/word_eval.py b/osh/word_eval.py
index 31d895b89..19733fe56 100644
--- a/osh/word_eval.py
+++ b/osh/word_eval.py
@@ -218,6 +218,10 @@ def _ValueToPartValue(val, quoted, part_loc):
             val = cast(value.BashArray, UP_val)
             return part_value.Array(bash_impl.BashArray_GetValues(val))
 
+        elif case(value_e.SparseArray):
+            val = cast(value.SparseArray, UP_val)
+            return part_value.Array(bash_impl.SparseArray_GetValues(val))
+
         elif case(value_e.BashAssoc):
             val = cast(value.BashAssoc, UP_val)
             # bash behavior: splice values!
@@ -685,10 +689,14 @@ def _ApplyTestOp(
                 else:
                     is_falsey = False
 
-            elif case(value_e.BashArray, value_e.BashAssoc):
+            elif case(value_e.BashArray, value_e.SparseArray,
+                      value_e.BashAssoc):
                 if val.tag() == value_e.BashArray:
                     val = cast(value.BashArray, UP_val)
                     strs = bash_impl.BashArray_GetValues(val)
+                elif val.tag() == value_e.SparseArray:
+                    val = cast(value.SparseArray, UP_val)
+                    strs = bash_impl.SparseArray_GetValues(val)
                 elif val.tag() == value_e.BashAssoc:
                     val = cast(value.BashAssoc, UP_val)
                     strs = bash_impl.BashAssoc_GetValues(val)
@@ -961,11 +969,15 @@ def _ApplyUnarySuffixOp(self, val, op):
                     #log('%r %r -> %r', val.s, arg_val.s, s)
                     new_val = value.Str(s)  # type: value_t
 
-                elif case(value_e.BashArray, value_e.BashAssoc):
+                elif case(value_e.BashArray, value_e.SparseArray,
+                          value_e.BashAssoc):
                     # get values
                     if val.tag() == value_e.BashArray:
                         val = cast(value.BashArray, UP_val)
                         values = bash_impl.BashArray_GetValues(val)
+                    elif val.tag() == value_e.SparseArray:
+                        val = cast(value.SparseArray, UP_val)
+                        values = bash_impl.SparseArray_GetValues(val)
                     elif val.tag() == value_e.BashAssoc:
                         val = cast(value.BashAssoc, UP_val)
                         values = bash_impl.BashAssoc_GetValues(val)
@@ -1024,10 +1036,14 @@ def _PatSub(self, val, op):
                 s = replacer.Replace(str_val.s, op)
                 val = value.Str(s)
 
-            elif case2(value_e.BashArray, value_e.BashAssoc):
+            elif case2(value_e.BashArray, value_e.SparseArray,
+                       value_e.BashAssoc):
                 if val.tag() == value_e.BashArray:
                     array_val = cast(value.BashArray, val)
                     values = bash_impl.BashArray_GetValues(array_val)
+                elif val.tag() == value_e.SparseArray:
+                    sparse_val = cast(value.SparseArray, val)
+                    values = bash_impl.SparseArray_GetValues(sparse_val)
                 elif val.tag() == value_e.BashAssoc:
                     assoc_val = cast(value.BashAssoc, val)
                     values = bash_impl.BashAssoc_GetValues(assoc_val)
@@ -1092,13 +1108,17 @@ def _Nullary(self, val, op, var_name, vsub_token, vsub_state):
                     # readline gets rid of these, so we should too.
                     p = prompt.replace('\x01', '').replace('\x02', '')
                     result = value.Str(p)
-                elif case(value_e.BashArray, value_e.BashAssoc):
+                elif case(value_e.BashArray, value_e.SparseArray,
+                          value_e.BashAssoc):
                     if val.tag() == value_e.BashArray:
                         val = cast(value.BashArray, UP_val)
                         values = [
                             s for s in bash_impl.BashArray_GetValues(val)
                             if s is not None
                         ]
+                    elif val.tag() == value_e.SparseArray:
+                        val = cast(value.SparseArray, UP_val)
+                        values = bash_impl.SparseArray_GetValues(val)
                     elif val.tag() == value_e.BashAssoc:
                         val = cast(value.BashAssoc, UP_val)
                         values = bash_impl.BashAssoc_GetValues(val)
@@ -1135,10 +1155,17 @@ def _Nullary(self, val, op, var_name, vsub_token, vsub_state):
                     # oddly, 'echo ${x@Q}' is equivalent to 'echo "${x@Q}"' in
                     # bash
                     quoted2 = True
-                elif case(value_e.BashArray, value_e.BashAssoc):
+                elif case(value_e.BashArray, value_e.SparseArray,
+                          value_e.BashAssoc):
                     if val.tag() == value_e.BashArray:
                         val = cast(value.BashArray, UP_val)
-                        values = [s for s in bash_impl.BashArray_GetValues(val) if s is not None]
+                        values = [
+                            s for s in bash_impl.BashArray_GetValues(val)
+                            if s is not None
+                        ]
+                    elif val.tag() == value_e.SparseArray:
+                        val = cast(value.SparseArray, UP_val)
+                        values = bash_impl.SparseArray_GetValues(val)
                     elif val.tag() == value_e.BashAssoc:
                         val = cast(value.BashAssoc, UP_val)
                         values = bash_impl.BashAssoc_GetValues(val)
@@ -1160,7 +1187,7 @@ def _Nullary(self, val, op, var_name, vsub_token, vsub_state):
             # spec/ble-idioms.test.sh.
             chars = []  # type: List[str]
             with tagswitch(vsub_state.h_value) as case:
-                if case(value_e.BashArray):
+                if case(value_e.BashArray, value_e.SparseArray):
                     chars.append('a')
                 elif case(value_e.BashAssoc):
                     chars.append('A')
@@ -1182,6 +1209,9 @@ def _Nullary(self, val, op, var_name, vsub_token, vsub_state):
                 elif case(value_e.BashArray):
                     val = cast(value.BashArray, UP_val)
                     count = bash_impl.BashArray_Count(val)
+                elif case(value_e.SparseArray):
+                    val = cast(value.SparseArray, UP_val)
+                    count = bash_impl.SparseArray_Count(val)
                 elif case(value_e.BashAssoc):
                     val = cast(value.BashAssoc, UP_val)
                     count = bash_impl.BashAssoc_Count(val)
diff --git a/spec/ble-idioms.test.sh b/spec/ble-idioms.test.sh
index fc14f0eac..1c3cd72c6 100644
--- a/spec/ble-idioms.test.sh
+++ b/spec/ble-idioms.test.sh
@@ -1064,6 +1064,153 @@ echo "[${a[@]: -4}][${a[*]: -4}]"
 ## END
 
 
+#### SparseArray: ${a[@]}
+
+case $SH in zsh|mksh|ash) exit ;; esac
+
+a=(v{0..9})
+unset -v 'a[2]' 'a[3]' 'a[4]' 'a[7]'
+case ${SH##*/} in osh) eval 'var a = _a2sp(a)' ;; esac
+
+argv.py "${a[@]}"
+argv.py "abc${a[@]}xyz"
+
+## STDOUT:
+['v0', 'v1', 'v5', 'v6', 'v8', 'v9']
+['abcv0', 'v1', 'v5', 'v6', 'v8', 'v9xyz']
+## END
+
+## N-I zsh/mksh/ash STDOUT:
+## END
+
+
+#### SparseArray: ${a[@]#...}
+
+case $SH in zsh|mksh|ash) exit ;; esac
+
+a=(v{0..9})
+unset -v 'a[2]' 'a[3]' 'a[4]' 'a[7]'
+case ${SH##*/} in osh) eval 'var a = _a2sp(a)' ;; esac
+
+argv.py "${a[@]#v}"
+argv.py "abc${a[@]#v}xyz"
+argv.py "${a[@]%[0-5]}"
+argv.py "abc${a[@]%[0-5]}xyz"
+argv.py "${a[@]#v?}"
+
+## STDOUT:
+['0', '1', '5', '6', '8', '9']
+['abc0', '1', '5', '6', '8', '9xyz']
+['v', 'v', 'v', 'v6', 'v8', 'v9']
+['abcv', 'v', 'v', 'v6', 'v8', 'v9xyz']
+['', '', '', '', '', '']
+## END
+
+## N-I zsh/mksh/ash STDOUT:
+## END
+
+
+#### SparseArray: ${a[@]/pat/rep}
+
+case $SH in zsh|mksh|ash) exit ;; esac
+
+a=(v{0..9})
+unset -v 'a[2]' 'a[3]' 'a[4]' 'a[7]'
+case ${SH##*/} in osh) eval 'var a = _a2sp(a)' ;; esac
+
+argv.py "${a[@]/?}"
+argv.py "${a[@]//?}"
+argv.py "${a[@]/#?}"
+argv.py "${a[@]/%?}"
+
+argv.py "${a[@]/v/x}"
+argv.py "${a[@]//v/x}"
+argv.py "${a[@]/[0-5]/D}"
+argv.py "${a[@]//[!0-5]/_}"
+
+## STDOUT:
+['0', '1', '5', '6', '8', '9']
+['', '', '', '', '', '']
+['0', '1', '5', '6', '8', '9']
+['v', 'v', 'v', 'v', 'v', 'v']
+['x0', 'x1', 'x5', 'x6', 'x8', 'x9']
+['x0', 'x1', 'x5', 'x6', 'x8', 'x9']
+['vD', 'vD', 'vD', 'v6', 'v8', 'v9']
+['_0', '_1', '_5', '__', '__', '__']
+## END
+
+## N-I zsh/mksh/ash STDOUT:
+## END
+
+
+#### SparseArray: ${a[@]@P}, ${a[@]@Q}, and ${a[@]@a}
+case $SH in zsh|mksh|ash) exit ;; esac
+
+a=(v{0..9})
+unset -v 'a[2]' 'a[3]' 'a[4]' 'a[7]'
+case ${SH##*/} in osh) eval 'var a = _a2sp(a)' ;; esac
+
+argv.py "${a[@]@P}"
+argv.py "${a[*]@P}"
+argv.py "${a[@]@Q}"
+argv.py "${a[*]@Q}"
+argv.py "${a[@]@a}"
+argv.py "${a[*]@a}"
+
+## STDOUT:
+['v0', 'v1', 'v5', 'v6', 'v8', 'v9']
+['v0 v1 v5 v6 v8 v9']
+['v0', 'v1', 'v5', 'v6', 'v8', 'v9']
+['v0 v1 v5 v6 v8 v9']
+['a', 'a', 'a', 'a', 'a', 'a']
+['a a a a a a']
+## END
+
+## OK bash STDOUT:
+['v0', 'v1', 'v5', 'v6', 'v8', 'v9']
+['v0 v1 v5 v6 v8 v9']
+["'v0'", "'v1'", "'v5'", "'v6'", "'v8'", "'v9'"]
+["'v0' 'v1' 'v5' 'v6' 'v8' 'v9'"]
+['a', 'a', 'a', 'a', 'a', 'a']
+['a a a a a a']
+## END
+
+## N-I zsh/mksh/ash STDOUT:
+## END
+
+
+#### SparseArray: ${a[@]-unset}, ${a[@]:-empty}, etc.
+case $SH in zsh|mksh|ash) exit ;; esac
+
+a1=()
+a2=("")
+a3=("" "")
+
+case $SH in
+bash) ;;
+*) eval "var a1 = _a2sp(a1); var a2 = _a2sp(a2); var a3 = _a2sp(a3)" ;;
+esac
+
+echo "a1 unset: [${a1[@]-unset}]"
+echo "a1 empty: [${a1[@]:-empty}]"
+echo "a2 unset: [${a2[@]-unset}]"
+echo "a2 empty: [${a2[@]:-empty}]"
+echo "a3 unset: [${a3[@]-unset}]"
+echo "a3 empty: [${a3[@]:-empty}]"
+
+## STDOUT:
+a1 unset: [unset]
+a1 empty: [empty]
+a2 unset: []
+a2 empty: [empty]
+a3 unset: [ ]
+a3 empty: [ ]
+## END
+
+## N-I zsh/mksh/ash STDOUT:
+## END
+
+
 #### SparseArray: compgen -F _set_COMPREPLY
 case $SH in zsh|mksh|ash) exit ;; esac