Implement #[]

README.md

@@ -55,8 +55,14 @@ Connect to a store within Redis.
 
 #### `#open`
 "Open" the store for reading and/or writing.
+##### Examples:
+```ruby
+store.open { |table| table[:key] = 5 }
+store.open { |table| table[:key] } #=> 5
+```
 ##### Parameters:
-- a block which receives `table` as its sole parameter
+- a block which receives `table` as its sole parameter. Changes to this Hash will
+  be persisted in the store.
    - `table` (Hash) The table belonging to `@name`
 ##### Returns:
 (Object) The return value of the block
@@ -65,9 +71,28 @@ Connect to a store within Redis.
 "Peek" inside the store, returning a copy of its table.
 Changes to this copy will NOT be persisted in the store.
 Use this if you simply need to fetch a value from the store.
+##### Examples:
+```ruby
+store.peek.key?(:test) #=> false
+```
 ##### Returns:
 (Hash) A copy of the store's table
 
+#### `#[]`
+Retrieve the object at `key` from the store.
+This is implemented using `#peek` and therefore
+changes to the object returned by this method will NOT
+be persisted in the store.
+Use this if you simply need to fetch a value from the store.
+##### Examples:
+```ruby
+store[:key] #=> 5
+```
+##### Parameters:
+- `key` (Object) The key to look up
+##### Returns:
+(Object) The object at `key`
+
 ---
 
 ### Geode::SequelStore
@@ -100,6 +125,17 @@ Use this if you simply need to fetch a value from the store.
 ##### Returns:
 (Hash) A copy of the store's table
 
+#### `#[]`
+Retrieve the object at `key` from the store.
+This is implemented using `#peek` and therefore
+changes to the object returned by this method will NOT
+be persisted in the store.
+Use this if you simply need to fetch a value from the store.
+##### Parameters:
+- `key` (Object) The key to look up
+##### Returns:
+(Object) The object at `key`
+
 ---
 
 ## Real-world example

lib/geode.rb

@@ -10,18 +10,39 @@ def initialize(name, connection = nil)
 
     # "Open" the store for reading and/or writing.
     # @yield a block which receives `table` as its sole parameter
-    # @yieldparam table [Hash] The table belonging to `@name`
+    # @yieldparam table [Hash] The store's table. Changes to this Hash will
+    # be persisted in the store
+    # When in doubt, use this method.
+    # @example
+    #   "store.open { |table| table[:key] = 5 }"
+    # @example
+    #   "store.open { |table| table[:key] } #=> 5"
     # @return [Object] The return value of the block
     def open
       raise NotImplementedError
     end
 
     # "Peek" inside the store, returning a copy of its table.
     # Changes to this copy will NOT be persisted in the store.
-    # Use this if you simply need to fetch a value from the store.
+    # Use this if you simply want to view the store's table.
+    # @example
+    #   "store.peek.key?(:test) #=> false"
     # @return [Hash] A copy of the store's table
     def peek
       open(&:itself)
     end
+
+    # Retrieve the object at `key` from the store.
+    # This is implemented using `#peek` and therefore
+    # changes to the object returned by this method will NOT
+    # be persisted in the store.
+    # Use this if you simply need to fetch a value from the store.
+    # @example
+    #   "store[:key] #=> 5"
+    # @param key [Object] The key to look up
+    # @return [Object] The object at `key`
+    def [](key)
+      peek[key]
+    end
   end
 end

test/geode_test.rb

@@ -39,7 +39,7 @@ def test_readme
       table[:time][:now] = Time.now
     end
 
-    p store.open { |table| table[:time] }
+    p store[:time]
     # {:now=>2021-10-15 16:34:22.664022392 +0100}
   end
 
@@ -53,4 +53,12 @@ def test_peek
     # but changes to it are not persisted
     refute_equal(@store.peek.clear, @store.peek)
   end
+
+  def test_reference
+    assert_nil @store[:anything]
+
+    @store.open { |table| table[:contents] = :here }
+
+    assert_equal(:here, @store[:contents])
+  end
 end