morphir-elm

morphir-elm is a set of tools to work with Morphir in Elm. It's dual published as an NPM and an Elm package:

• NPM package
• Elm package

NPM package

The morphir-elm NPM package provides a CLI to run the tooling.

Installation

npm install -g morphir-elm

Usage

All the features can be accessed through sub-commands within the morphir-elm command:

morphir-elm [command]

Each command has different options which are detailed below:

Translate Elm sources to Morphir IR

This command reads Elm sources, translates to Morphir IR and outputs the IR into JSON.

morphir-elm make [options]

Important: The command requires a configuration file called morphir.json located in the project root directory with the following structure:

{
    "name": "My.Package",
    "sourceDirectory": "src",
    "exposedModules": [
        "Foo",
        "Bar"
    ]
}

• name - The name of the package. The package name should be a valid Elm module name and it should be used as a module prefix in your Elm models. If your package name is My.Package all your module files should either be directly under that or in submodules.
• sourceDirectory - The directory where your Elm sources are located.
• exposedModules - The list of modules in the public interface of the package. Module names should exclude the common package prefix. In the above example Foo refers to the Elm module My.Package.Foo.

Options

• --project-dir <path>, -p
  • Root directory of the project where morphir.json is located.
  • Defaults to current directory.
• --output <path>, -o
  • Target location where the Morphir IR will be sent
  • Defaults to STDOUT.

Elm package

The Morgan-Stanley/morphir-elm package provides various tools to work with Morphir. It contains the following main components:

• The Morphir SDK which provides the base set of types and functions that Morphir tools support out-of-the-box. (the SDK is a superset elm/core with a few exceptions documented below)
• A type-safe API for the Morphir IR that allows you to create or inspect it.

Installation

elm install Morgan-Stanley/morphir-elm

Morphir SDK

The goal of the Morphir.SDK module is to provide you the basic building blocks to build your domain model and business logic. It also serves as a specification for backend developers that describes the minimum set of functionality each backend implementation should support.

It is generally based on elm/core/1.0.5 and provides most of the functionality provided there except for some modules that fall outside the scope of business knowledge modeling: Debug, Platform, Process and Task.

Apart from the modules mentioned above you can use everything that's available in elm/core/1.0.5 without importing the Morphir SDK. The Elm frontend will simply map those to the corresponding type/function names in the Morphir SDK.

The Morphir SDK also provides some features beyond elm/core/1.0.5. To use those features you have to import the specific Morphir SDK module. Modules that extends elm/core will implement the same functions so in general you can use an alias if you want to switch from the elm/core module to the Morphir SDK version. For example if you want to use extended List functions you can do the below an all existing code should continue to work without changes:

import Morphir.SDK.List as List

Morphir IR

The Morphir.IR module defines a type-safe API to work with Morphir's intermediate representation. The module structure follows the structure of the IR. Here's a list of concepts in a top-down approach:

• Package represents an entire library or application that is versioned as a whole. A package is made up of several modules.
• Module is a container to group types and values.
• Types allow you to describe your domain model.
• Values allows you to describe your business logic.
• Names provide a naming convention agnostic representation for all nodes that can be named: types, values, modules and packages. Names can be composed into hierarchies:
  • path is a list of names
  • qualifield name is a module path with a local name
  • fully-qualifield name is a package path with a qualified name
• AccessControlled is a utility to define visibility constraints for modules, types and values