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  Documentation/API for the Molecule library - a meta DSL for the Datomic database.

  Manual | scalamolecule.org | Github | Forum

  Definition Classes

  root

•  package molecule

  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.

  Sub-packages

  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.

  Definition Classes

  root

•  package generic

  Definition Classes

  molecule

•  package index

  Datomic Index APIs in Molecule.

  Datomic Index APIs in Molecule.
  
  Datomic maintains four indexes that contain ordered sets of datoms. Each of these indexes is named based on the sort order used:

  • EAVT - Datoms sorted by Entity-Attribute-Value-Transaction
  • AVET - Datoms sorted by Attribute-Value-Entity-Transaction
  • AEVT - Datoms sorted by Attribute-Entity-Value-Transaction
  • VAET - "Reverse index" for reverse lookup of ref types

  Create an Index molecule by instantiating an Index object with one or more arguments in the order of the Index's elements. Datoms are returned as tuples of data depending of which generic attributes you add to the Index molecule:

  // Create EAVT Index molecule with 1 entity id argument
  EAVT(e1).e.a.v.t.get === List(
    (e1, ":Person/name", "Ben", t1),
    (e1, ":Person/age", 42, t2),
    (e1, ":Golf/score", 5.7, t2)
  )
  
  // Maybe we are only interested in the attribute/value pairs:
  EAVT(e1).a.v.get === List(
    (":Person/name", "Ben"),
    (":Person/age", 42),
    (":Golf/score", 5.7)
  )
  
  // Two arguments to narrow the search
  EAVT(e1, ":Person/age").a.v.get === List(
    (":Person/age", 42)
  )

  Definition Classes

  generic

  Note

  The Molecule Index API's don't allow returning the whole Index/the whole database. So omitting arguments constructing the Index object (like EAVT.e.a.v.t.get) will throw an exception.
  Please use Datomics API if you need to return the whole database Index:
  conn.db.datoms(datomic.Database.EAVT)

  See also

  Tests for more Index query examples.

• AEVT
• AEVT_0
• AEVT_1
• AEVT_2
• AEVT_3
• AEVT_4
• AEVT_5
• AEVT_6
• AEVT_7
• AVET
• AVET_0
• AVET_1
• AVET_2
• AVET_3
• AVET_4
• AVET_5
• AVET_6
• AVET_7
• EAVT
• EAVT_0
• EAVT_1
• EAVT_2
• EAVT_3
• EAVT_4
• EAVT_5
• EAVT_6
• EAVT_7
• GenericAEVT
• GenericAVET
• GenericEAVT
• GenericVAET
• VAET
• VAET_0
• VAET_1
• VAET_2
• VAET_3
• VAET_4
• VAET_5
• VAET_6
• VAET_7

molecule.generic.index

AVET_3