refactor iterator with crystal-0.20.1 or higher

README.md

@@ -2,7 +2,7 @@
 
 RocksDB client for [Crystal](http://crystal-lang.org/).
 
-- crystal: 0.20.0
+- crystal: 0.20.3 (at least 0.20.1 needed)
 
 
 ## Supported API

shard.yml

@@ -4,6 +4,6 @@ version: 0.4.0
 authors:
   - maiha <maiha@wota.jp>
 
-crystal: 0.20.0
+crystal: 0.20.3
 
 license: MIT

spec/commands/iteration_spec.cr

@@ -34,7 +34,7 @@ describe "Iterations" do
   it "#new_iterator" do
     db = RocksDB::DB.new(path)
     iter = db.new_iterator
-    iter.should be_a(RocksDB::Iterator)
+    iter.should be_a(RocksDB::StringIterator)
     iter.close
     db.close
   end

spec/iterator_spec.cr

@@ -6,7 +6,7 @@ describe "Iterator" do
   it "work" do
     db = RocksDB::DB.new(path)
     3.times{|i| db.put("k#{i}", i) }
-    iter = RocksDB::Iterator.new(db)
+    iter = RocksDB::StringIterator.new(db)
 
     iter.valid?.should be_false
 

src/rocksdb/commands/iteration.cr

@@ -2,7 +2,7 @@ module RocksDB::Commands
   include Api
 
   def new_iterator
-    Iterator.new(self)
+    StringIterator.new(self)
   end
 
   def each(&block)

src/rocksdb/iterator.cr

@@ -1,17 +1,9 @@
-#abstract class RocksDB::Iterator(T)
-class RocksDB::Iterator
+abstract class RocksDB::Iterator(T)
   include Api
   include RawMemory(LibRocksDB::RocksdbIteratorT)
 
-#  protected abstract def zero : T
-#  protected abstract def underlying(ptr, size) : T
-  protected def zero
-    ""
-  end
-
-  protected def underlying(ptr, size) : String
-    String.new(ptr, size)
-  end
+  protected abstract def zero : T
+  protected abstract def underlying(ptr, size) : T
 
   def initialize(@db : DB, r_opts : ReadOptions? = nil)
     opts = (r_opts || @db.r_opts).not_nil!
@@ -73,7 +65,6 @@ class RocksDB::Iterator
 
 end
 
-{% if flag?(:fixed_issue3635) %}
 module RocksDB
   class StringIterator < Iterator(String)
     protected def zero
@@ -85,4 +76,3 @@ module RocksDB
     end
   end
 end
-{% end %}