Packages

  • package root

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

    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.

    Definition Classes
    root
  • package core
    Definition Classes
    molecule
  • package api
    Definition Classes
    core
  • package exception
    Definition Classes
    api
  • package getAsyncObj

    Asynchronous getter methods to retrieve data as objects.

    Asynchronous getter methods to retrieve data as objects.

    For convenience, all synchronous getter methods from the get package are here wrapped in Futures.

    The Datomic On-Prem(ises) server model provides a Peer that returns data synchronously. The Peer which lives in application memory caches data aggressively and for data fitting in memory, latency can be extremely low and queries return very fast. And even when access to disk is needed, clever branching is used. Memcached is also an option.

    The Datomic Cloud model data returns data asynchronously. If Datomic creates a Java API for the Cloud model, Molecule could relatively easy adapt to this model too. In the meanwhile, Future-wrapped methods in this package can be used.

    Molecule has 4 groups of asynchronous getters for objects, each returning Futures of data in various formats:

    • GetAsyncObjArray - fastest retrieved typed data set. Can be traversed with a fast while loop
    • GetAsyncObjIterable - for lazily traversing row by row
    • GetAsyncObjList - default getter returning Lists of objects. Convenient typed data, suitable for smaller data sets
    • GetAsyncRaw - fastest retrieved raw un-typed data from Datomic

    Getters in each of the 4 groups come with 5 time-dependent variations:

    • getAsync [current data]
    • getAsyncAsOf
    • getAsyncSince
    • getAsyncWith
    • getAsyncHistory

    Each time variation has various overloads taking different parameters (see each group for more info).

    Definition Classes
    api
    See also

    equivalent synchronous getters in the getTpl package.

  • package getAsyncTpl

    Asynchronous getter methods to retrieve tuples of data.

    Asynchronous getter methods to retrieve tuples of data.

    For convenience, all synchronous getter methods from the get package are here wrapped in Futures.

    The Datomic On-Prem(ises) server model provides a Peer that returns data synchronously. The Peer which lives in application memory caches data aggressively and for data fitting in memory, latency can be extremely low and queries return very fast. And even when access to disk is needed, clever branching is used. Memcached is also an option.

    The Datomic Cloud model data returns data asynchronously. If Datomic creates a Java API for the Cloud model, Molecule could relatively easy adapt to this model too. In the meanwhile, Future-wrapped methods in this package can be used.

    Molecule has 4 groups of asynchronous getters for tuples, each returning Futures of data in various formats:

    • GetAsyncTplArray - fastest retrieved typed data set. Can be traversed with a fast while loop
    • GetAsyncTplIterable - for lazily traversing row by row
    • GetAsyncTplList - default getter returning Lists of tuples. Convenient typed data, suitable for smaller data sets
    • GetAsyncRaw - fastest retrieved raw un-typed data from Datomic

    Getters in each of the 4 groups come with 5 time-dependent variations:

    • getAsync [current data]
    • getAsyncAsOf
    • getAsyncSince
    • getAsyncWith
    • getAsyncHistory

    Each time variation has various overloads taking different parameters (see each group for more info).

    Definition Classes
    api
    See also

    equivalent synchronous getters in the getTpl package.

  • package getObj

    Synchronous getter methods to retrieve data as objects.

    Synchronous getter methods to retrieve data as objects.

    The Datomic On-Prem(ises) server model provides a Peer that returns data synchronously. The Peer which lives in application memory caches data aggressively and for data fitting in memory latency can be extremely low and queries return very fast. And even when access to disk is needed, clever branching is used. Memcached is also an option.

    The Datomic Cloud model data returns data asynchronously. If Datomic creates a Java API for the Cloud model, Molecule could relatively easy adapt to this model too. In the meanwhile, Future-wrapped methods in this package can be used.

    Molecule has 3 groups of synchronous object getters, each returning data in various formats:

    • GetObjArray - fastest retrieved typed data set. Can be traversed with a fast while loop
    • GetObjIterable - for lazily traversing row by row
    • GetObjList - default getter returning Lists of objects. Convenient typed data, suitable for smaller data sets

    Getters in each of the 5 groups come with 5 time-dependent variations:

    • get [current data]
    • getAsOf
    • getSince
    • getWith
    • getHistory

    Each time variation has various overloads taking different parameters (see each group for more info).

    Definition Classes
    api
    See also

    equivalent asynchronous getters in the getAsyncTpl package.

  • package getTpl

    Synchronous getter methods to retrieve data as tuples.

    Synchronous getter methods to retrieve data as tuples.

    The Datomic On-Prem(ises) server model provides a Peer that returns data synchronously. The Peer which lives in application memory caches data aggressively and for data fitting in memory latency can be extremely low and queries return very fast. And even when access to disk is needed, clever branching is used. Memcached is also an option.

    Molecule has 4 groups of synchronous tuple getters, each returning data in various formats:

    • GetTplArray - fastest retrieved typed data set. Can be traversed with a fast while loop
    • GetTplIterable - for lazily traversing row by row
    • GetTplList - default getter returning Lists of tuples. Convenient typed data, suitable for smaller data sets
    • GetRaw - fastest retrieved raw un-typed data from Datomic

    Getters in each of the 4 groups come with 5 time-dependent variations:

    • get [current data]
    • getAsOf
    • getSince
    • getWith
    • getHistory

    Each time variation has various overloads taking different parameters (see each group for more info).

    Definition Classes
    api
    See also

    equivalent asynchronous getters in the getAsyncTpl package.

  • GetAsyncRaw
  • GetRaw
  • InputMolecule
  • Keywords
  • Molecule_0
  • Molecule_1
  • Molecule_2
  • Molecule_3
  • OptionalMapOps
  • TxBundles
  • TxFunctions
o

molecule.core.api

Keywords

object Keywords extends Keywords

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Inherited
  1. Keywords
  2. Keywords
  3. AttrExpressions
  4. AggregateKeywords
  5. AnyRef
  6. Any
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  1. Public
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Type Members

  1. type ?? = expression.AttrExpressions.?
    Definition Classes
    AttrExpressions
  2. type unify_stable = expression.AttrExpressions.unify
    Definition Classes
    AttrExpressions
  3. trait avg extends AnyRef

    Average of attribute values.

    Average of attribute values.

    Apply avg keyword to attribute to return average of attribute values of entities matching the molecule.

    Match.sKeywords.insert(1, 2, 4)
Match.score(avg).get.head === 2.3333333333333335 // (1 + 2 + 4) / 3
    returns

    Double

    Definition Classes
    AggregateKeywords
  4. trait count extends AnyRef

    Count of attribute values.

    Count of attribute values.

    Apply count keyword to attribute to return count of attribute values of entities matching the molecule.

    Person.firstName.lastName.age insert List(
  ("Ben", "Hayday", 42),
  ("Liz", "Taylor", 34),
  ("Liz", "Swifty", 34),
  ("Liz", "Mooray", 25)
)
Person.firstName.age(count).get === List(
  ("Ben", 1),
  ("Liz", 3) // 34, 34, 25
)
    returns

    Int

    Definition Classes
    AggregateKeywords
  5. trait countDistinct extends AnyRef

    Count of distinct attribute values.

    Count of distinct attribute values.

    Apply countDistinct keyword to attribute to return count of distinct attribute values of entities matching the molecule.

    Person.firstName.lastName.age insert List(
  ("Ben", "Hayday", 42),
  ("Liz", "Taylor", 34),
  ("Liz", "Swifty", 34),
  ("Liz", "Mooray", 25)
)
Person.firstName.age(countDistinct).get === List(
  ("Ben", 1),
  ("Liz", 2) // 34, 25
)
    returns

    Int

    Definition Classes
    AggregateKeywords
  6. trait distinct extends AnyRef

    Distinct attribute values.

    Distinct attribute values.

    Apply distinct keyword to attribute to return Vector of distinct attribute values of entities matching the molecule.

    Person.firstName.lastName.age insert List(
  ("Ben", "Hayday", 42),
  ("Liz", "Taylor", 34),
  ("Liz", "Swifty", 34),
  ("Liz", "Mooray", 25)
)
Person.firstName.age(distinct) insert List(
  ("Ben", 42),
  ("Liz", Vector(34, 25)) // only single 34 returned
)
    returns

    List[attribute-type]

    Definition Classes
    AggregateKeywords
  7. trait max extends AnyRef

    Maximum attribute value(s).

    Maximum attribute value(s).

    Apply max keyword to attribute to return the maximum attribute value of entities matching the molecule.

    Person.age.insert(25, 34, 37, 42, 70)
Person.age(max).get.head === 70

    Apply max(n) to return Vector of the n biggest values.

    Person.age(max(3)).get.head === Vector(37, 42, 70)
    Definition Classes
    AggregateKeywords
    Note

    max/max(n) supports all value types (via comparators).
    max(n) Can at most return the number of values that match.

  8. trait maxs extends AnyRef
    Definition Classes
    AggregateKeywords
  9. trait median extends AnyRef

    Median of attribute values.

    Median of attribute values.

    Apply median keyword to attribute to return median of attribute values of entities matching the molecule.

    Match.sKeywords.insert(1, 2, 4)
Match.score(median).get.head === 2

    OBS: When it comes to an even number of values, Datomic has a special implementation of median that is different from the one described on the Wiki entry on the median function.

    Datomic calculates the median of even number of values as the average of the two middle numbers rounded down to nearest whole number

    Match.sKeywords.insert(1, 2, 3, 4)
Match.score(median).get.head === 2 // (2 + 3) / 2 = 2.5 rounded down to 2

    With decimal numbers this can go wrong:

    Match.sKeywords.insert(1.0, 2.5, 2.5, 3.0)
Match.score(median).get.head === 2 // (2.5 + 2.5) / 2 = 2.5 rounded down to 2 (This is wrong and bug report has been filed)
    returns

    Value of Attribute type

    Definition Classes
    AggregateKeywords
  10. trait min extends AnyRef

    Minimum attribute value(s).

    Minimum attribute value(s).

    Apply min keyword to attribute to return the minimum attribute value of entities matching the molecule.

    Person.age.insert(25, 34, 37, 42, 70)
Person.age(min).get.head === 25

    Apply min(n) to return Vector of the n smallest values.

    Person.age(min(3)).get.head === Vector(25, 34, 37)
    Definition Classes
    AggregateKeywords
    Note

    min/min(n) supports all value types (via comparators).
    min(n) Can at most return the number of values that match.

  11. trait mins extends AnyRef
    Definition Classes
    AggregateKeywords
  12. trait rand extends AnyRef

    Random attribute value(s).

    Random attribute value(s).

    Apply random keyword to attribute to return a single random attribute of entities matching the molecule.

    Person.age.insert(25, 34, 37, 42, 70)
Person.age(random).get.head === 34 // or other..

    Apply random(n) to return Vector of n random values. Observe though that duplicate random values can re-occur.

    Person.age(random(3)).get.head === Vector(42, 25, 42) // or other..

    To get distinct values only, use the sample(n) keyword instead.

    Definition Classes
    AggregateKeywords
  13. trait rands extends AnyRef
    Definition Classes
    AggregateKeywords
  14. trait sample extends AnyRef

    Sample attribute value(s).

    Sample attribute value(s).

    Apply sample keyword to attribute to return a single sample (random) attribute value of entities matching the molecule.

    Person.age.insert(25, 34, 37, 42, 70)
Person.age(sample).get.head === 42 // or other..

    Apply sample(n) to return Vector of up to n distinct sample values.

    Person.age(sample(3)).get.head === Vector(70, 25, 37) // or other..

    If values don't need to be distinct, random(n) can be used also.

    Definition Classes
    AggregateKeywords
    Note

    Can at most return the number of values that match.

  15. trait samples extends AnyRef
    Definition Classes
    AggregateKeywords
  16. trait stddev extends AnyRef

    Variance of attribute values.

    Variance of attribute values.

    Apply stddev keyword to attribute to return variance of attribute values of entities matching the molecule.

    Match.sKeywords.insert(1, 2, 4)
Match.score(stddev).get.head === 1.247219128924647
    returns

    Double

    Definition Classes
    AggregateKeywords
  17. trait sum extends AnyRef

    Sum of attribute values.

    Sum of attribute values.

    Apply sum keyword to attribute to return sum of attribute values of entities matching the molecule.

    Match.sKeywords.insert(1, 2, 4)
Match.score(sum).get.head === 7
    returns

    Value of Attribute type

    Definition Classes
    AggregateKeywords
  18. trait variance extends AnyRef

    Variance of attribute values.

    Variance of attribute values.

    Apply variance keyword to attribute to return variance of attribute values of entities matching the molecule.

    Match.sKeywords.insert(1, 2, 4)
Match.score(variance).get.head === 1.5555555555555556
    returns

    Double

    Definition Classes
    AggregateKeywords
  19. trait ? extends AnyRef

    Turn molecule into input molecule awaiting input.

    Turn molecule into input molecule awaiting input.

    Apply input marker ? to attribute to turn molecule into an 'input molecule'.

    At runtime the input molecule expects input for the attribute in place of the ? marker.

    // Input molecule created at compile time.
val ageOfPersons = m(Person.name_(?).age) // awaiting name of type String

// At runtime, "Ben" is applied as input replacing the `?` placeholder and we can get the age.
ageOfPersons("Ben").get === List(42)
    Definition Classes
    AttrExpressions
    Note

    Data can only be retrieved from input molecules once they have been resolved with input.
    Input molecule queries are cached and optimized by Datomic.

  20. trait AttrExpr[Ns, T] extends AnyRef

    Expression methods common for all attributes.

    Expression methods common for all attributes.

    Definition Classes
    AttrExpressions
  21. trait FulltextExpr[Ns, In] extends AnyRef

    Expression methods of String attributes with fulltext search.

    Expression methods of String attributes with fulltext search.

    Definition Classes
    AttrExpressions
  22. trait ManyAttrExpr[Ns, Add, OldNew, Rem] extends AnyRef

    Value update methods for card-many attributes.

    Value update methods for card-many attributes.

    Definition Classes
    AttrExpressions
  23. trait ManyExpr[Ns, In, T] extends ValueAttrExpr[Ns, In, T] with ManyAttrExpr[Ns, T, (T, T), T]

    Expression methods of card-many attributes.

    Expression methods of card-many attributes.

    Definition Classes
    AttrExpressions
  24. trait MapAttrExpr[Ns, In, T] extends ValueAttrExpr[Ns, In, T] with ManyAttrExpr[Ns, (String, T), (String, T), String]

    Expression methods of map attributes.

    Expression methods of map attributes.

    Definition Classes
    AttrExpressions
  25. trait OneExpr[Ns, In, T] extends ValueAttrExpr[Ns, In, T]

    Expression methods of card-one attributes.

    Expression methods of card-one attributes.

    Definition Classes
    AttrExpressions
  26. trait OptionalExpr[Ns, T] extends AnyRef

    Expression methods of optional attributes.

    Expression methods of optional attributes.

    Definition Classes
    AttrExpressions
  27. trait ValueAttrExpr[Ns, In, T] extends AttrExpr[Ns, T]

    Expression methods of value attributes.

    Expression methods of value attributes.

    Definition Classes
    AttrExpressions
  28. trait unify extends AnyRef

    Unify attribute value in self-join.

    Unify attribute value in self-join.

    Apply unify marker to attribute to unify its value with previous values of the same attribute in the molecule in a self-join.

    m(Person.age.name.Beverages * Beverage.name.rating) insert List(
    (23, "Joe", List(("Coffee", 3), ("Cola", 2), ("Pepsi", 3))),
    (25, "Ben", List(("Coffee", 2), ("Tea", 3))),
    (23, "Liz", List(("Coffee", 1), ("Tea", 3), ("Pepsi", 1))))

// What beverages do pairs of 23- AND 25-year-olds like in common?
// Drink name is unified - Joe and Ben both drink coffee, etc..
Person.age_(23).name.Beverages.name._Ns.Self
      .age_(25).name.Beverages.name_(unify).get.sorted === List(
  ("Joe", "Coffee", "Ben"),
  ("Liz", "Coffee", "Ben"),
  ("Liz", "Tea", "Ben")
)
    Definition Classes
    AttrExpressions

Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int
    Definition Classes
    AnyRef → Any
  3. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  4. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  5. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()
  6. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  7. def equals(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  8. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  9. final def getClass(): Class[_]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  10. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  11. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  12. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  13. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  14. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  15. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  16. def toString(): String
    Definition Classes
    AnyRef → Any
  17. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  18. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  19. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()
  20. object avg extends avg
    Definition Classes
    Keywords
  21. object count extends count
    Definition Classes
    Keywords
  22. object countDistinct extends countDistinct
    Definition Classes
    Keywords
  23. object distinct extends distinct
    Definition Classes
    Keywords
  24. object max extends max
    Definition Classes
    Keywords
  25. object median extends median
    Definition Classes
    Keywords
  26. object min extends min
    Definition Classes
    Keywords
  27. object rand extends rand
    Definition Classes
    Keywords
  28. object sample extends sample
    Definition Classes
    Keywords
  29. object stddev extends stddev
    Definition Classes
    Keywords
  30. object sum extends sum
    Definition Classes
    Keywords
  31. object unify extends expression.AttrExpressions.unify
    Definition Classes
    Keywords
  32. object variance extends variance
    Definition Classes
    Keywords

Inherited from Keywords

Inherited from AttrExpressions

Inherited from AggregateKeywords

Inherited from AnyRef

Inherited from Any

Attribute markers

Markers applied to attributes that change the semantics of the attribute/molecule.

Aggregate keywords

Keywords applied to attributes that return aggregated value(s).

Number aggregation keywords

Keywords applied to number attributes that return aggregated value(s).

Ungrouped