Molecule library - a Scala meta-DSL for the Datomic database.
Molecule library - a Scala meta-DSL for the Datomic database.
See api package for various api imports to start using Molecule.
| api | Molecule API. | |
| ast | Internal Molecule ASTs. | |
| boilerplate | Internal interfaces for auto-generated DSL boilerplate code. | |
| composition | Builder methods to compose molecules. | |
| exceptions | Exceptions thrown by Molecule. | |
| expression | Attribute expressions and operations. | |
| facade | Molecule facades to Datomic. | |
| factory | Implicit macro methods `m` to instantiate molecules from custom DSL molecule constructs. | |
| input | Input molecules awaiting input. | |
| macros | Internal macros generating molecule code from custom DSL molecule constructs. | |
| generic | Interfaces to generic information about datoms and Datomic database. | |
| ops | Internal operational helpers for transforming DSL to molecule. | |
| schema | Schema definition DSL. | |
| transform | Internal transformers from DSL to Model/Query/Transaction. | |
| util | Internal Java database functions for Datomic. |
Input molecules awaiting input.
Input molecules awaiting input.
Input molecules are molecules that awaits one or more inputs at runtime. When input value is applied,
the input molecule is resolved and a standard molecule is returned that we can then call actions on.
Input molecule queries are cached by Datomic. So there is a runtime performance gain in using input molecules. Furthermore,
input molecules are a good fit for re-use for queries where only a few parameters change.
Input molecules can await 1, 2 or 3 inputs and are constructed by applying the ? marker
to attributes. If one marker is applied, we get a InputMolecule_1, 2 inputs creates
an InputMolecule_2 and 3 an InputMolecule_3.
The three input molecule interfaces come in arity-versions corresponding to the number of non-?-marked attributes
in the input molecule. Let's see a simple example:
// Sample data Person.name.age insert List(("Ben", 42), ("Liz", 34)) // Input molecule created at compile time. Awaits a name of type String val ageOfPersons: InputMolecule_1.InputMolecule_1_01[String, Int] = m(Person.name_(?).age) // Resolved molecule. "Ben" input is matched against name attribute val ageOfPersonsNamedBen: Molecule.Molecule01[Int] = ageOfPersons.apply("Ben") // Calling action on resolved molecule. // (Only age is returned since name was marked as tacit with the underscore notation) ageOfPersonsNamedBen.get === List(42) // Or we can re-use the input molecule straight away ageOfPersons("Liz").get === List(34)
Documentation/API for the Molecule library - a meta DSL for the Datomic database.
Manual | scalamolecule.org | Github | Forum