GH-37979: [C++] Add support for specifying custom Array opening and closing delimiters to arrow::PrettyPrintDelimiters

cpp/src/arrow/pretty_print.cc

@@ -87,7 +87,7 @@ void PrettyPrinter::OpenArray(const Array& array) {
   if (!options_.skip_new_lines) {
     Indent();
   }
-  (*sink_) << "[";
+  (*sink_) << options_.array_delimiters.open;
   if (array.length() > 0) {
     Newline();
     indent_ += options_.indent_size;
@@ -101,7 +101,7 @@ void PrettyPrinter::CloseArray(const Array& array) {
       Indent();
     }
   }
-  (*sink_) << "]";
+  (*sink_) << options_.array_delimiters.close;
 }
 
 void PrettyPrinter::Write(std::string_view data) { (*sink_) << data; }
@@ -449,7 +449,7 @@ Status PrettyPrint(const ChunkedArray& chunked_arr, const PrettyPrintOptions& op
   for (int i = 0; i < indent; ++i) {
     (*sink) << " ";
   }
-  (*sink) << "[";
+  (*sink) << options.chunked_array_delimiters.open;
   if (!skip_new_lines) {
     *sink << "\n";
   }
@@ -488,7 +488,7 @@ Status PrettyPrint(const ChunkedArray& chunked_arr, const PrettyPrintOptions& op
   for (int i = 0; i < indent; ++i) {
     (*sink) << " ";
   }
-  (*sink) << "]";
+  (*sink) << options.chunked_array_delimiters.close;
 
   return Status::OK();
 }

cpp/src/arrow/pretty_print.h

@@ -36,6 +36,12 @@ class Table;
 /// \brief Options for controlling which delimiters to use when printing
 /// an Array or ChunkedArray.
 struct ARROW_EXPORT PrettyPrintDelimiters {
+  /// Delimiter to use when opening an Array or ChunkedArray (e.g. "[")
+  std::string open = "[";
+
+  /// Delimiter to use when closing an Array or ChunkedArray (e.g. "]")
+  std::string close = "]";
+
   /// Delimiter for separating individual elements of an Array (e.g. ","),
   /// or individual chunks of a ChunkedArray
   std::string element = ",";

cpp/src/arrow/pretty_print_test.cc

@@ -259,6 +259,25 @@ TEST_F(TestPrettyPrint, ArrayCustomElementDelimiter) {
   }
 }
 
+TEST_F(TestPrettyPrint, ArrayCustomOpenCloseDelimiter) {
+  PrettyPrintOptions options{};
+  // Use a custom opening Array delimiter of "{", rather than the default "]".
+  options.array_delimiters.open = "{";
+  // Use a custom closing Array delimiter of "}", rather than the default "]".
+  options.array_delimiters.close = "}";
+
+  std::vector<bool> is_valid = {true, true, false, true, false};
+  std::vector<int32_t> values = {1, 2, 3, 4, 5};
+  static const char* expected = R"expected({
+  1,
+  2,
+  null,
+  4,
+  null
+})expected";
+  CheckPrimitive<Int32Type, int32_t>(options, is_valid, values, expected, false);
+}
+
 TEST_F(TestPrettyPrint, Int8) {
   static const char* expected = R"expected([
   0,
@@ -1131,6 +1150,60 @@ TEST_F(TestPrettyPrint, ChunkedArrayCustomElementDelimiter) {
   }
 }
 
+TEST_F(TestPrettyPrint, ChunkedArrayCustomOpenCloseDelimiter) {
+  PrettyPrintOptions options{};
+  // Use a custom opening Array delimiter of "{", rather than the default "]".
+  options.array_delimiters.open = "{";
+  // Use a custom closing Array delimiter of "}", rather than the default "]".
+  options.array_delimiters.close = "}";
+  // Use a custom opening ChunkedArray delimiter of "<", rather than the default "]".
+  options.chunked_array_delimiters.open = "<";
+  // Use a custom closing ChunkedArray delimiter of ">", rather than the default "]".
+  options.chunked_array_delimiters.close = ">";
+
+  const auto chunk = ArrayFromJSON(int32(), "[1, 2, null, 4, null]");
+
+  // ChunkedArray with 1 chunk
+  {
+    const ChunkedArray chunked_array(chunk);
+
+    static const char* expected = R"expected(<
+  {
+    1,
+    2,
+    null,
+    4,
+    null
+  }
+>)expected";
+    CheckStream(chunked_array, options, expected);
+  }
+
+  // ChunkedArray with 2 chunks
+  {
+    const ChunkedArray chunked_array({chunk, chunk});
+
+    static const char* expected = R"expected(<
+  {
+    1,
+    2,
+    null,
+    4,
+    null
+  },
+  {
+    1,
+    2,
+    null,
+    4,
+    null
+  }
+>)expected";
+
+    CheckStream(chunked_array, options, expected);
+  }
+}
+
 TEST_F(TestPrettyPrint, TablePrimitive) {
   std::shared_ptr<Field> int_field = field("column", int32());
   auto array = ArrayFromJSON(int_field->type(), "[0, 1, null, 3, null]");