From 928c1517dc0e31354a733905f935e938cdef587e Mon Sep 17 00:00:00 2001
From: "Brian J. Cardiff" <bcardiff@manas.com.ar>
Date: Fri, 19 Feb 2016 18:42:30 -0300
Subject: [PATCH] update to 0.12 features clarify expected protocol with
 ResultSet in docs minor refactors suggested

---
 src/db/connection.cr |  5 +----
 src/db/db.cr         |  2 +-
 src/db/driver.cr     |  3 ---
 src/db/result_set.cr |  8 ++++++++
 src/db/statement.cr  | 18 +++++++++---------
 5 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/src/db/connection.cr b/src/db/connection.cr
index 5980cb9..ddd61a9 100644
--- a/src/db/connection.cr
+++ b/src/db/connection.cr
@@ -28,10 +28,7 @@ module DB
     # :nodoc:
     def prepare(query) : Statement
       stmt = @statements_cache.fetch(query, nil)
-      if stmt.is_a?(Nil)
-        stmt = build_statement(query)
-        @statements_cache[query] = stmt
-      end
+      stmt = @statements_cache[query] = build_statement(query) unless stmt
 
       stmt
     end
diff --git a/src/db/db.cr b/src/db/db.cr
index abbdf2c..149e367 100644
--- a/src/db/db.cr
+++ b/src/db/db.cr
@@ -79,7 +79,7 @@ module DB
   record ExecResult, rows_affected, last_insert_id
 
   # :nodoc:
-  def self.driver_class(driver_name) # : Driver.class
+  def self.driver_class(driver_name) : Driver.class
     @@drivers.not_nil![driver_name]
   end
 
diff --git a/src/db/driver.cr b/src/db/driver.cr
index 35e5713..49fc6e7 100644
--- a/src/db/driver.cr
+++ b/src/db/driver.cr
@@ -26,9 +26,6 @@ module DB
   # Refer to `Connection`, `Statement` and `ResultSet` for further
   # driver implementation instructions.
   abstract class Driver
-    def initialize
-    end
-
     abstract def build_connection(db : Database) : Connection
   end
 end
diff --git a/src/db/result_set.cr b/src/db/result_set.cr
index 3bb4aa6..8dbaa54 100644
--- a/src/db/result_set.cr
+++ b/src/db/result_set.cr
@@ -4,6 +4,14 @@ module DB
   # See `DB` for a complete sample.
   #
   # Each `#read` call consumes the result and moves to the next column.
+  # Each column must be read in order.
+  # At any moment a `#move_next` can be invoked, meaning to skip the
+  # remaining, or even all the columns, in the current row.
+  # Also it is not mandatory to consume the whole `ResultSet`, hence an iteration
+  # through `#each` or `#move_next` can be stopped.
+  #
+  # **Note:** depending on how the `ResultSet` was obtained it might be mandatory an
+  # explicit call to `#close`. Check `QueryMethods#query`.
   #
   # ### Note to implementors
   #
diff --git a/src/db/statement.cr b/src/db/statement.cr
index b4b777e..175c162 100644
--- a/src/db/statement.cr
+++ b/src/db/statement.cr
@@ -46,23 +46,23 @@ module DB
       query(*args) do |rs|
         rs.each do
           # return case rs.read?(rs.column_type(0)) # :-( Some day...
-          t = rs.column_type(0)
-          if t == String
+          case rs.column_type(0)
+          when String.class
             return rs.read?(String)
-          elsif t == Int32
+          when Int32.class
             return rs.read?(Int32)
-          elsif t == Int64
+          when Int64.class
             return rs.read?(Int64)
-          elsif t == Float32
+          when Float32.class
             return rs.read?(Float32)
-          elsif t == Float64
+          when Float64.class
             return rs.read?(Float64)
-          elsif t == Slice(UInt8)
+          when Slice(UInt8).class
             return rs.read?(Slice(UInt8))
-          elsif t == Nil
+          when Nil.class
             return rs.read?(Int32)
           else
-            raise "not implemented for #{t} type"
+            raise "not implemented for #{rs.column_type(0)} type"
           end
         end
       end