generator/templates/art/api_kotlin_async_helpers.kt

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package {{ kotlin_package }}

import kotlin.coroutines.resume
import kotlin.coroutines.suspendCoroutine
{% from 'art/api_kotlin_types.kt' import kotlin_declaration, kotlin_definition with context %}

//* Provide an async wrapper for the 'callback info' type of async methods.
{% for obj in by_category['object'] %}
    {% for method in obj.methods if has_callbackInfoStruct(method) %}
        {% set callback_info = method.arguments[-1].type %}
        {% set callback_function = callback_info.members[-1].type %}
        {% set return_name = callback_function.name.chunks[:-1] | map('title') | join + 'Return' %}

        //* We make a return class for every callback method so that it can be used inline
        //* (without callbacks) in a suspend (async) function.
        public data class {{ return_name }}(
            {% for arg in kotlin_record_members(callback_function.arguments) %}
                val {{ as_varName(arg.name) }}: {{ kotlin_declaration(arg) }},
            {% endfor %})

        //* Every method that is identified as using callbacks is given a helper method that wraps
        //* call with a suspend function.
        public suspend fun {{ obj.name.CamelCase() }}.{{ method.name.camelCase() }}(
            {%- for arg in method.arguments[:-1] %}
                {{- as_varName(arg.name) }}: {{ kotlin_definition(arg) }},
            {%- endfor %}): {{ return_name }} = suspendCoroutine {
                {{ method.name.camelCase() }}(
                    {%- for arg in method.arguments %}
                        {{- as_varName(arg.name) }}
                        {%- if loop.last %}
                            //* The final parameter of a callback method is always callback info.
                            //* We make this and include our generated callback.
                            {{- ' = ' }}
                            {{- callback_info.name.CamelCase() }}(CallbackMode.AllowSpontaneous)
                        {%- else %}
                            //* Non-final parameters are whatever the client supplied.
                            {{- ', ' }}
                        {%- endif %}
                    {%- endfor %}{
                    {%- for arg in kotlin_record_members(callback_function.arguments) %}
                        {{- as_varName(arg.name) }},
                    {%- endfor %} -> it.resume({{ return_name }}(
                        //* We make an instance of the callback parameters -> return type wrapper.
                        {%- for arg in kotlin_record_members(callback_function.arguments) %}
                            {{- as_varName(arg.name) }} {{ ', ' }}
                        {%- endfor %})
                    )
                })
            }
    {% endfor %}
{% endfor %}