Simplify Postgres::PGRange#inspect output

This also simplifies Postgres::PGMultiRange#inspect output, since
a multi range is implemented as a delegate class of Array containing
PGRange.

Author: jeremyevans

CHANGELOG

@@ -1,5 +1,7 @@
 === master
 
+* Simplify Postgres::PGRange#inspect output (jeremyevans)
+
 * Add deprecated_associations plugin, for warning/raising for deprecated association access (jeremyevans)
 
 * Clear all cached schema information when using Database#drop_schema on PostgreSQL (jeremyevans)

lib/sequel/extensions/pg_range.rb

@@ -421,6 +421,17 @@ def exclude_end?
         @exclude_end
       end
 
+      # Support a friendly output
+      def inspect
+        range = if empty?
+          "empty"
+        else
+          "#{@exclude_begin ? "(" : "["}#{@begin},#{@end}#{@exclude_end ? ")" : "]"}"
+        end
+
+        "#<#{self.class.name} #{range}#{"::#{@db_type}" if @db_type}>"
+      end
+
       # Append a literalize version of the receiver to the sql.
       def sql_literal_append(ds, sql)
         if (s = @db_type) && !empty?

spec/extensions/pg_range_spec.rb

@@ -24,6 +24,13 @@ def default_timestamp_format
   endless_range_support = RUBY_VERSION >= '2.6'
   startless_range_support = RUBY_VERSION >= '2.7'
 
+  it "should have friendly #inspect output" do
+    @R.new(1,2).inspect.must_equal "#<Sequel::Postgres::PGRange [1,2]>"
+    @R.new(1,2, :exclude_begin=>true, :exclude_end=>true, :db_type=>'int4range').inspect.must_equal "#<Sequel::Postgres::PGRange (1,2)::int4range>"
+    @R.new(nil, nil, :empty=>true).inspect.must_equal "#<Sequel::Postgres::PGRange empty>"
+    @R.new(nil, nil, :empty=>true, :db_type=>'int4range').inspect.must_equal "#<Sequel::Postgres::PGRange empty::int4range>"
+  end
+
   it "should set up conversion procs correctly" do
     cp = @db.conversion_procs
     cp[3904].call("[1,2]").must_equal @R.new(1,2, :exclude_begin=>false, :exclude_end=>false, :db_type=>'int4range')