Macro key_schema 

macro_rules! key_schema {
    {
        $(#[$meta:meta])*
        $ksname:ident {
            type SortKey = $skty:ty;
            type PartitionKey = $pkty:ty;
        }
    } => { ... };
    {
        $(#[$meta:meta])*
        $ksname:ident {
            type PartitionKey = $pkty:ty;
            type SortKey = $skty:ty;
        }
    } => { ... };
    {
        $(#[$meta:meta])*
        $ksname:ident {
            type PartitionKey = $pkty:ty;
        }
    } => { ... };
    ($($tt:tt)*) => { ... };
}

Defines a key schema struct implementing KeySchema.

This is a lower-level macro used internally by table_definitions! and index_definitions!. You can use it directly when you need a named key schema type outside of a table or index definition.

Generates a pub struct that implements:

• KeySchema — always
• SimpleKeySchema — when only PartitionKey is given
• CompositeKeySchema — when both PartitionKey and SortKey are given

Syntax

Simple key (partition key only):

key_schema! {
    MySchema {
        type PartitionKey = MyPkAttr;
    }
}

Composite key (partition + sort key):

key_schema! {
    MySchema {
        type PartitionKey = MyPkAttr;
        type SortKey = MySkAttr;
    }
}

The PartitionKey and SortKey fields may appear in either order.

The given types must implement AttributeDefinition and will typically have been created using attribute_definitions!

Examples

use dynamodb_facade::{key_schema, CompositeKeySchema, KeySchema, SimpleKeySchema};

key_schema! {
    UserSchema {
        type PartitionKey = PK;
        type SortKey = SK;
    }
}

key_schema! {
    ConfigSchema {
        type PartitionKey = PK;
    }
}

fn _assert_composite<KS: CompositeKeySchema>() {}
fn _assert_simple<KS: SimpleKeySchema>() {}

_assert_composite::<UserSchema>();
_assert_simple::<ConfigSchema>();