[osh] Implement SparseArray $sp as ${sp[0]} (#2222)

oils-for-unix · Jan 4, 2025 · f4f49ac · f4f49ac
1 parent 25161ff
commit f4f49ac
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Showing 2 changed files with 37 additions and 5 deletions.
diff --git a/osh/word_eval.py b/osh/word_eval.py
@@ -110,9 +110,16 @@ def ShouldArrayDecay(var_name, exec_opts, is_plain_var_sub=True):
 def DecayArray(val):
     # type: (value_t) -> value_t
     """Resolve ${array} to ${array[0]}."""
-    if val.tag() == value_e.BashArray:
-        array_val = cast(value.BashArray, val)
-        s, error_code = bash_impl.BashArray_GetElement(array_val, 0)
+    if val.tag() in (value_e.BashArray, value_e.SparseArray):
+        if val.tag() == value_e.BashArray:
+            array_val = cast(value.BashArray, val)
+            s, error_code = bash_impl.BashArray_GetElement(array_val, 0)
+        elif val.tag() == value_e.SparseArray:
+            sparse_val = cast(value.SparseArray, val)
+            s, error_code = bash_impl.SparseArray_GetElement(
+                sparse_val, mops.ZERO)
+        else:
+            raise AssertionError(val.tag())
 
         # Note: index 0 should never cause the out-of-bound index error.
         assert error_code == error_code_e.OK
@@ -1419,7 +1426,8 @@ def _EvalBracketOp(self, val, part, quoted, vsub_state, vtest_place):
         else:  # no bracket op
             var_name = vtest_place.name
             if (var_name is not None and
-                    val.tag() in (value_e.BashArray, value_e.BashAssoc)):
+                    val.tag() in (value_e.BashArray, value_e.SparseArray,
+                                  value_e.BashAssoc)):
                 if ShouldArrayDecay(var_name, self.exec_opts,
                                     not (part.prefix_op or part.suffix_op)):
                     # for ${BASH_SOURCE}, etc.
@@ -1698,7 +1706,8 @@ def _EvalSimpleVarSub(self, part, part_vals, quoted):
             var_name = lexer.LazyStr(token)
             # TODO: Special case for LINENO
             val = self.mem.GetValue(var_name)
-            if val.tag() in (value_e.BashArray, value_e.BashAssoc):
+            if val.tag() in (value_e.BashArray, value_e.SparseArray,
+                             value_e.BashAssoc):
                 if ShouldArrayDecay(var_name, self.exec_opts):
                     # for $BASH_SOURCE, etc.
                     val = DecayArray(val)

diff --git a/spec/ble-idioms.test.sh b/spec/ble-idioms.test.sh
@@ -1211,6 +1211,29 @@ a3 empty: [ ]
 ## END
 
 
+#### SparseArray: ${a-}
+case $SH in zsh|mksh|ash) exit ;; esac
+
+a1=()
+a2=("" "")
+a3=(foo bar)
+
+case ${SH##*/} in osh) eval 'var a1 = _a2sp(a1); var a2 = _a2sp(a2); var a3 = _a2sp(a3)' ;; esac
+
+echo "$a1, ${a1-(unset)}, ${a1:-(empty)};"
+echo "$a2, ${a2-(unset)}, ${a2:-(empty)};"
+echo "$a3, ${a3-(unset)}, ${a3:-(empty)};"
+
+## STDOUT:
+, (unset), (empty);
+, , (empty);
+foo, foo, foo;
+## END
+
+## N-I zsh/mksh/ash STDOUT:
+## END
+
+
 #### SparseArray: compgen -F _set_COMPREPLY
 case $SH in zsh|mksh|ash) exit ;; esac