README.md in smart_initializer-0.8.0 vs README.md in smart_initializer-0.9.0

@@ -30,23 +30,23 @@
 ## Table of contents
 
 - [Synopsis](#synopsis)
   - [Initialization flow](#initialization-flow)
   - [Attribute value definition flow](#attribute-value-definition-flow-during-object-allocation-and-construction)
-  - [Constructor definition](#constructor-definition)
+  - [Constructor definition DSL](#constructor-definition-dsl)
     - [param](#param)
     - [option](#option)
     - [params](#params)
     - [options](#options)
-    - [param and params signature](#param-and-params-signature)
+    - [param and params signature](#param-and-params-signautre)
     - [option and options signature](#option-and-options-signature)
 - [Initializer integration](#initializer-integration)
 - [Basic Example](#basic-example)
 - [Access to the instance attributes](#access-to-the-instance-attributes)
 - [Configuration](#configuration)
 - [Type aliasing](#type-aliasing)
-- [Type auto-casting](#type-auto-casting)
+- [Type casting](#type-casting)
 - [Initialization extension](#initialization-extension)
 - [Plugins](#plugins)
   - [thy-types](#plugin-thy-types)
 - [Roadmap](#roadmap)
 - [Build](#build)
@@ -55,26 +55,49 @@
 
 ## Synopsis
 
 #### Initialization flow
 
-1. Parameter + Option definitioning and initialization;
+1. Parameter + Option definitioning and initialization (custom object allocator and constructor);
 2. Original **#initialize** invokation;
 3. Initialization extensions invokation;
 
-**NOTE!**: original constructor is called after **SmarteCore::Initializer**'s constructor
+**NOTE!**:  **SmarteCore::Initializer**'s constructor is invoked first
 in order to guarantee the validity of the SmartCore::Initializer's functionality
 (such as `attribute overlap chek`, `instant type checking`, `value post-processing by finalize`, etc)
 
 #### Attribute value definition flow (during object allocation and construction):
 
 1. `original value`
 2. *(if defined)*: `default value` (default value is used when `original value` is not defined)
 3. *(if defined)*: `finalize`;
 
----
+**NOTE**: `:finalize` block are not invoked on omitted `optional: true` attributes
+which has no `:default` definition bock and which are not passed to the constructor. Example:
 
+```ruby
+# without :default
+
+class User
+  include SmartCore::Initializer
+  option :age, :string, optional: true, finalize: -> (val) { "#{val}_years" }
+end
+
+User.new.age # => nil
+```
+
+```ruby
+# with :default
+
+class User
+  include SmartCore::Initializer
+  option :age, :string, optional: true, default: '0', finalize: -> (val) { "#{val}_years" }
+end
+
+User.new.age # => '0_years'
+```
+
 ### Constructor definition DSL
 
 **NOTE**: last `Hash` argument will be treated as `kwarg`s;
 
 #### param
@@ -88,11 +111,11 @@
   - `mutable` (optional) - generate type-validated attr_writer in addition to attr_reader (`false` by default)
   - (**limitation**) param has no `:default` option;
 
 #### option
 
-- `option` - defined kwarg-like attribute:
+- `option` - defines kwarg-like attribute:
   - `cast` (optional) - type-cast received value if value has invalid type;
   - `privacy` (optional) - reader incapsulation level;
   - `as` (optional) - attribute alias (be careful with naming aliases that overlap the names of other attributes);
   - `mutable` (optional) - generate type-validated attr_writer in addition to attr_reader (`false` by default)
   - `optional` (optional) - mark attribut as optional (you can may not initialize optional attributes,
@@ -104,17 +127,17 @@
     - non-proc values will be `dup`licate during initialization;
   - `type_system` (optional) - differently chosen type system for the current attribute;
 
 #### params
 
-- `params` - define a series of parameters;
+- `params` - defines a series of parameters;
   - `:mutable` (optional) - (`false` by default);
   - `:privacy` (optional) - (`:public` by default);
 
 #### options
 
-- `options` - define a series of options;
+- `options` - defines a series of options;
   - `:mutable` (optional) - (`false` by default);
   - `:privacy` (optional) - (`:public` by default);
 
 
 #### `param` and `params` signautre:
@@ -497,10 +520,13 @@
 
 ---
 
 ## Roadmap
 
-- (**thinking** / **discussing**) Finalize should be invoked on `mutable` attributes after mutation too;
+- More semantic attribute declaration errors (more domain-related attribute error objects);
+  - incorrect `:finalize` argument type: `ArgumentError` => `FinalizeArgumentError`;
+  - incorrect `:as` argument type: `ArguemntError` => `AsArgumentError`;
+  - etc;
 - Support for `RSpec` doubles and instance_doubles inside the type system integration;
 - Specs restructuring;
 - Migrate from `TravisCI` to `GitHub Actions`;
 - Extract `Type Interop` system to `smart_type-system`;