spartanz/schemaz
{ "createdAt": "2018-07-08T05:49:57Z", "defaultBranch": "prototyping", "description": "A purely-functional library for defining type-safe schemas for algebraic data types, providing free generators, SQL queries, JSON codecs, binary codecs, and migration from this schema definition", "fullName": "spartanz/schemaz", "homepage": "https://spartanz.github.io/schemaz", "language": "Scala", "name": "schemaz", "pushedAt": "2020-01-28T10:36:26Z", "stargazersCount": 164, "topics": [], "updatedAt": "2025-10-12T16:30:33Z", "url": "https://github.com/spartanz/schemaz"}SchemaZ
Section titled “SchemaZ”
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A purely-functional library for defining type-safe schemas for algebraic data types, providing free generators, SQL queries, JSON codecs, binary codecs, and migration from this schema definition.
Introduction & Highlights
Section titled “Introduction & Highlights”SchemaZ defines a generic representation of algebraic data structures and combinators that turn such schema into a generic computation over arbitrary data. In other words, SchemaZ provides a way to express any computation that abstracts over the structure of data, such as:
- Codecs: given a serial format (binary, JSON, etc.) and the schema of a data structure (say, an ADT) we can derive a codec for that data structure and serial format.
- Data Generators: given any schema we can derive random data generators (eg. scalacheck’s
Gen) that produce data satisfying that schema. - Schema/Data Migrations: since schemas are values, we can easily verify whether two versions of a schema are forward/backward compatible and provide a generic way to upgrade/downgrade data from one version of the schema to the other.
- Diffing/Patching: given a schema we can generically compute the difference between two pieces of data satisfying that schema. In the same spirit, we have generic way to apply patches to arbitrary data structures.
- Queries: knowing a schema, we can produce SQL queries to interact with a database that holds an instance of (the SQL version of) that schema.
Competition
Section titled “Competition”| codecs | generators | migrations | diff/patch | queries | |
|---|---|---|---|---|---|
| xenomorph | ✓ | ✓ | ? | 𐄂 | 𐄂 |
| shapeless * | ✓ | ✓ | 𐄂 | ✓ | 𐄂 |
*: shapeless provides only the way to abstract over the structure of data, but several libraries build upon shapeless to provide the feature listed in the table.
Skeumorph is also a possible competitor, however it is focused on providing translation between different formats (Avro, Protobuf and Mu). This is achieved by using a central Schema Representation which can losslessly translate to each of the previously mentioned formats.
Background
Section titled “Background”SchemaZ shares ideas with @nuttycom’s xenomorph library. The talk below presents its design.
An Haskell port of the ideas of xenomorph has also been implemented: haskell-schema.