smithy-lang · JordonPhillips · Jan 20, 2022 · Jan 13, 2022 · Jan 13, 2022 · Jan 14, 2022
diff --git a/designs/mixins.md b/designs/mixins.md
@@ -348,7 +348,7 @@ The members and traits applied to members of a mixin are copied onto the target
 shape. It is sometimes necessary to provide a more specific trait value for a
 copied member or to add traits only to a specific copy of a member. Traits can
 be added on to these members like any other member. Additionally, Traits can be
-applied to  these members in the JSON AST using the `apply` type and in the
+applied to these members in the JSON AST using the `apply` type and in the
 Smithy IDL using `apply` statements.
 
 > Note: Traits applied to shapes supersede any traits inherited from mixins.

diff --git a/docs/source/1.0/spec/core/idl.rst b/docs/source/1.0/spec/core/idl.rst
@@ -180,21 +180,26 @@ The Smithy IDL is defined by the following ABNF:
                                  :/ `service_statement`
                                  :/ `operation_statement`
                                  :/ `resource_statement`
-    simple_shape_statement :`simple_type_name` `ws` `identifier`
+    mixins                 :`sp` "with" `ws` "[" 1*(`ws` `shape_id`) `ws` "]"
+    simple_shape_statement :`simple_type_name` `ws` `identifier` [`mixins`]
     simple_type_name       :"blob" / "boolean" / "document" / "string"
                            :/ "byte" / "short" / "integer" / "long"
                            :/ "float" / "double" / "bigInteger"
                            :/ "bigDecimal" / "timestamp"
     shape_members          :"{" `ws` *(`shape_member_kvp` `ws`) "}"
     shape_member_kvp       :`trait_statements` `identifier` `ws` ":" `ws` `shape_id`
-    list_statement :"list" `ws` `identifier` `ws` `shape_members`
-    set_statement :"set" `ws` `identifier` `ws` `shape_members`
-    map_statement :"map" `ws` `identifier` `ws` `shape_members`
-    structure_statement     :"structure" `ws` `identifier` `ws` `shape_members`
-    union_statement :"union" `ws` `identifier` `ws` `shape_members`
-    service_statement :"service" `ws` `identifier` `ws` `node_object`
-    operation_statement :"operation" `ws` `identifier` `ws` `node_object`
-    resource_statement :"resource" `ws` `identifier` `ws` `node_object`
+    list_statement :"list" `ws` `identifier` [`mixins`] `ws` `shape_members`
+    set_statement :"set" `ws` `identifier` [`mixins`] `ws` `shape_members`
+    map_statement :"map" `ws` `identifier` [`mixins`] `ws` `shape_members`
+    structure_statement     :"structure" `ws` `identifier` [`mixins`] `ws` `shape_members`
+    union_statement :"union" `ws` `identifier` [`mixins`] `ws` `shape_members`
+    service_statement :"service" `ws` `identifier` [`mixins`] `ws` `node_object`
+    operation_statement :"operation" `ws` `identifier` [`mixins`] `ws` `inlineable_properties`
+    inlineable_properties  :"{" *(`inlineable_property` `ws`) `ws` "}"
+    inlineable_property    :`node_object_kvp` / `inline_structure`
+    inline_structure       :`node_object_key` `ws` ":=" `ws` `inline_structure_value`
+    inline_structure_value :`trait_statements` [`mixins` ws] shape_members
+    resource_statement :"resource" `ws` `identifier` [`mixins`] `ws` `node_object`
 
 .. rubric:: Traits
 
@@ -250,11 +255,30 @@ The :token:`control section <smithy:control_section>` of a model contains
 :token:`control statements <smithy:control_statement>` that apply parser directives
 to a *specific IDL file*. Because control statements influence parsing, they
 MUST appear at the beginning of a file before any other statements and have
-no effect on the :ref:`semantic model <semantic-model>`
+no effect on the :ref:`semantic model <semantic-model>` The following control
+statements are currently supported:
 
-The :ref:`version <smithy-version>` statement is currently the only control
-statement defined in the Smithy IDL. Implementations MUST ignore unknown
-control statements.
+.. list-table::
+    :header-rows: 1
+    :widths: 10 10 80
+
+    * - Name
+      - Type
+      - Description
+    * - version
+      - string
+      - Defines the :ref:`version <smithy-version>` of the Smithy IDL used in
+        the model file.
+    * - operationInputSuffix
+      - string
+      - Defines the suffix used when generating names for
+        :ref:`inline operation input <idl-inline-input-output>`.
+    * - operationOutputSuffix
+      - string
+      - Defines the suffix used when generating names for
+        :ref:`inline operation output <idl-inline-input-output>`.
+
+Implementations MUST ignore unknown control statements.
 
 
 .. _smithy-version:
@@ -1100,8 +1124,8 @@ Operation shape
 ---------------
 
 An operation shape is defined using an :token:`smithy:operation_statement` and the
-provided :token:`smithy:node_object` supports the same properties defined in the
-:ref:`operation specification <operation>`.
+provided :token:`smithy:inlineable_properties` supports the same properties defined
+in the :ref:`operation specification <operation>`.
 
 The following example defines an operation shape that accepts an input
 structure named ``Input``, returns an output structure named ``Output``, and
@@ -1146,6 +1170,109 @@ can potentially return the ``Unavailable`` or ``BadRequest``
         }
 
 
+.. _idl-inline-input-output:
+
+Inline input / output shapes
+++++++++++++++++++++++++++++
+
+The input and output properties of operations can be defined using a more
+succinct, inline syntax.
+
+A structure defined using inline syntax is automatically marked with the
+:ref:`input-trait` for inputs and the :ref:`output-trait` for outputs.
+
+A structure defined using inline syntax is given a generated shape name. For
+inputs, the generated name is the name of the operation shape with the suffix
+``Input`` added. For outputs, the generated name is the name of the operation
+shape with the ``Output`` suffix added.
+
+For example, the following model:
+
+.. code-block:: smithy
+
+    operation GetUser {
+        // The generated shape name is GetUserInput
+        input := {
+            userId: String
+        }
+
+        // The generated shape name is GetUserOutput
+        output := {
+            username: String
+            userId: String
+        }
+    }
+
+Is equivalent to:
+
+.. code-block:: smithy
+
+    operation GetUser {
+        input: GetUserInput
+        output: GetUserOutput
+    }
+
+    @input
+    structure GetUserInput {
+        userId: String
+    }
+
+    @output
+    structure GetUserOutput {
+        username: String
+        userId: String
+    }
+
+Traits and mixins can be applied to the inline structure:
+
+.. code-block:: smithy
+
+    @mixin
+    structure BaseUser {
+        userId: String
+    }
+
+    operation GetUser {
+        input := @references([{resource: User}]) {
+            userId: String
+        }
+
+        output := with [BaseUser] {
+            username: String
+        }
+    }
+
+    operation PutUser {
+        input :=
+            @references([{resource: User}])
+            with [BaseUser] {}
+    }
+
+The suffixes for the generated names can be customized using the
+``operationInputSuffix`` and ``operationOutputSuffix`` control statements.
+
+.. code-block:: smithy
+
+    $version: "2.0"
+    $operationInputSuffix: "Request"
+    $operationInputSuffix: "Response"
+
+    namespace smithy.example
+
+    operation GetUser {
+        // The generated shape name is GetUserRequest
+        input := {
+            userId: String
+        }
+
+        // The generated shape name is GetUserResponse
+        output := {
+            username: String
+            userId: String
+        }
+    }
+
+
 .. _idl-resource:
 
 Resource shape
@@ -1191,6 +1318,35 @@ and defines a :ref:`read <read-lifecycle>` operation:
         }
 
 
+.. _idl-mixins:
+
+Mixins
+------
+
+:ref:`Mixins <mixins>` can be added to a shape using the optional
+:token:`smithy:mixins` clause of a shape definition.
+
+For example:
+
+.. code-block:: smithy
+
+    @mixin
+    structure BaseUser {
+        userId: String
+    }
+
+    structure UserDetails with [BaseUser] {
+        username: String
+    }
+
+    @mixin
+    @sensitive
+    string SensitiveString
+
+    @pattern("^[a-zA-Z\.]*$")
+    string SensitiveText with [SensitiveString]
+
+
 .. _documentation-comment:
 
 Documentation comment

diff --git a/docs/source/1.0/spec/core/json-ast.rst b/docs/source/1.0/spec/core/json-ast.rst
@@ -638,6 +638,50 @@ The following example defines an operation, its input, output, and errors:
     }
 
 
+.. ast-mixins:
+
+------
+Mixins
+------
+
+All shapes in the ``shapes`` map can contain a ``mixins`` property that
+defines the :ref:`mixins` that are added to the shape. ``mixins`` is an
+array of :ref:`shape references <ast-shape-reference>` that target shapes
+marked with the :ref:`mixin trait <mixin-trait>`.
+
+.. code-block:: json
+
+    {
+        "smithy": "2.0",
+        "shapes": {
+            "smithy.example#BaseUser": {
+                "type": "structure",
+                "members": {
+                    "userId": {
+                        "target": "smithy.api#String"
+                    }
+                },
+                "traits": {
+                    "smithy.api#mixin": {}
+                }
+            },
+            "smithy.example#UserDetails": {
+                "type": "structure",
+                "members": {
+                    "username": {
+                        "target": "smithy.api#String"
+                    }
+                },
+                "mixins": [
+                    {
+                        "target": "smithy.example#BaseUser"
+                    }
+                ]
+            }
+        }
+    }
+
+
 .. _ast-apply:
 
 --------------