MPS Open Source

This repository contains open source "stuff" (languages, mainly) made with/in/for JetBrains MPS (=Meta-Programming System).

Open the directory mps-open-source inside this repository in MPS as a project. You have to define a path variable called mps-open-source in the Preferences, which points to this (inner) mps-open-source directory.

Development currently takes place with MPS version 2019.3.3 (#MPS-193.1331).

Languages

Json

This language encapsulates the JSON DOMs using the famous Jackson library for JSON/XML (de-)serialisation. That approach avoids escaping problems and such.

JsonSchema

This language aims to deliver the same expressive power and semantics of the official JSON Schema standard (draft version #7).

I don't intend to do that with the exact same syntax and structure of the original JSON, but opt to provide a cleaner syntax with less syntactic noise (m.n. enclosing {} and ""), and a better editing experience.

As an example: object properties are either regular, or patterned, and co-exist happily together. It's the job of the mapping to actual JSON (conforming to the JSON Schema meta-schema) to pull these apart in the way that JSON Schema prescribes. I think this allows the schema author to organise their properties in the way they want.

Another facet is that I don't intend to support default values (at this time): this mixes validation with pure data concerns.

The longer term goal of this is to also provide an OpenAPI specification language which meshes with the JSON Schema language.

Useful links:

• The specification - draft-07
• The corresponding
• Corresponding to models under Examples: productSet, entry, mainEntry
• A very good explanation.

WSDL, XSD, (XmlWithExtension)

These language serve as a slight abstraction of WSDL, resp, XSD. The XmlWithExtension is an extension of the XML language built into MPS, that allows to specify an extension -such as .wsdl or .xsd- for an XML file.

TODOs w.r.t. languages

Somewhat in order of rather shallowly descending importance:

• Implement import facilities for JSON (using Jackson), WSDL, XML.
• Expand the JsonSchema language to be able to cope with the meta-schema (or currently: an official one) for JSON Schema.
• Implement being able to validate a JSON model with/against a JSON Schema model.
• Implement constraints/validations such as name validity in the languages.
• Avoid having to use the Inspector for input (e.g., 2 occurrences in the XSD language).

MPS Analyser

The MPS Analyser is a commandline tool meant for use in conjunction with JetBrains' MPS, working directly on MPS project files. For further information: see here.