Generated with

Molecule/molecule/molecule.boilerplate/molecule.boilerplate.api/KeywordsStable

KeywordsStable

molecule.boilerplate.api.KeywordsStable

Keywords to mark aggregate expressions on and unifications of attributes.

// Aggregates on any attribute type
Person.age(count).get.map(_.head ==> 3)         // count of asserted `age` attribute values
Person.age(countDistinct).get.map(_.head ==> 3) // count of asserted distinct `age` attribute values
Person.age(max).get.map(_.head ==> 38)          // maximum `age` value (using `compare`)
Person.age(min).get.map(_.head ==> 5)           // maximum `age` value (using `compare`)
Person.age(sample).get.map(_.head ==> 27)       // single sample `age` value

// Aggregates on any attribute type, returning multiple values
Person.age(distinct).get.map(_.head ==> Vector(5, 7, 38)) // distinct `age` values
Person.age(max(2)).get.map(_.head ==> Vector(38, 7))      // 2 maximum `age` values
Person.age(min(2)).get.map(_.head ==> Vector(5, 7))       // 2 minimum `age` values
Person.age(sample(2)).get.map(_.head ==> Vector(7, 38))   // 2 sample `age` values

// Aggregates on number attributes
Person.age(sum).get.map(_.head ==> 50)                  // sum of all `age` numbers
Person.age(avg).get.map(_.head ==> 16.66666667)         // average of all `age` numbers
Person.age(median).get.map(_.head ==> 7)                // median of all `age` numbers
Person.age(stddev).get.map(_.head ==> 15.107025591499)  // standard deviation of all `age` numbers
Person.age(variance).get.map(_.head ==> 228.2222222222) // variance of all `age` numbers

Attributes

Source: Keywords.scala
Graph
Supertypes: class Object

trait Matchable

class Any
Known subtypes: object Keywords.type

Members list

Grouped members

Aggregate keywords

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

Count of attribute values.

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

for {
 _ <- Person.firstName.lastName.age insert List(
   ("Ben", "Hayday", 42),
   ("Liz", "Taylor", 34),
   ("Liz", "Swifty", 34),
   ("Liz", "Mooray", 25)
 )
 _ <- Person.firstName.age(count).get.map(_ ==> List(
   ("Ben", 1),
   ("Liz", 3) // 34, 34, 25
 ))
} yield ()

Attributes

Returns: Int
Source: Keywords.scala
Supertypes: trait AggrInt

trait AggrCoalesce

trait AggrKw

trait Kw

class Object

trait Matchable

class Any
Show all
Known subtypes: object count.type

Count of distinct attribute values.

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

for {
 _ <- Person.firstName.lastName.age insert List(
   ("Ben", "Hayday", 42),
   ("Liz", "Taylor", 34),
   ("Liz", "Swifty", 34),
   ("Liz", "Mooray", 25)
 )
 _ <- Person.firstName.age(countDistinct).get.map(_ ==> List(
   ("Ben", 1),
   ("Liz", 2) // 34, 25
 ))
} yield ()

Attributes

Returns: Int
Source: Keywords.scala
Supertypes: trait AggrCoalesce

trait AggrKw

trait Kw

class Object

trait Matchable

class Any
Show all
Known subtypes: object countDistinct.type

Distinct attribute values.

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

for {
 _ <- 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
 )
} yield ()

Attributes

Returns: List[attribute-type]
Source: Keywords.scala
Supertypes: trait AggrKw

trait Kw

class Object

trait Matchable

class Any
Known subtypes: object distinct.type

Maximum attribute value(s).

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

for {
 _ <- Person.age.insert(25, 34, 37, 42, 70)
 _ <- Person.age(max).get.map(_.head ==> 70)
} yield ()

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

Person.age(max(3)).get.map(_.head ==> Vector(37, 42, 70))

Attributes

Note: max/max(n) supports all value types (via comparators).
max(n) Can at most return the number of values that match.
Source: Keywords.scala
Supertypes: trait AggrKw

trait Kw

class Object

trait Matchable

class Any
Known subtypes: object max.type

Minimum attribute value(s).

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

for {
 _ <- Person.age.insert(25, 34, 37, 42, 70)
 _ <- Person.age(min).get.map(_.head ==> 25)
} yield ()

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

Person.age(min(3)).get.map(_.head ==> Vector(25, 34, 37))

Attributes

Note: min/min(n) supports all value types (via comparators).
min(n) Can at most return the number of values that match.
Source: Keywords.scala
Supertypes: trait AggrKw

trait Kw

class Object

trait Matchable

class Any
Known subtypes: object min.type

Sample attribute value(s).

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

for {
 _ <- Person.age.insert(25, 34, 37, 42, 70)
 _ <- Person.age(sample).get.map(_.head ==> 42) // or other..
} yield ()

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

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

Attributes

Note: Can at most return the number of values that match.
Source: Keywords.scala
Supertypes: trait AggrKw

trait Kw

class Object

trait Matchable

class Any
Known subtypes: object sample.type

Number aggregation keywords

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

Average of attribute values.

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

for {
 _ <- Match.sKeywords.insert(1, 2, 4)
 _ <- Match.score(avg).get.map(_.head ==> 2.3333333333333335) // (1 + 2 + 4) / 3
} yield ()

Attributes

Returns: Double
Source: Keywords.scala
Supertypes: trait AggrCoalesce

trait AggrKw

trait Kw

class Object

trait Matchable

class Any
Show all
Known subtypes: object avg.type

Median of attribute values.

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

for {
 _ <- Match.sKeywords.insert(1, 2, 4)
 _ <- Match.score(median).get.map(_.head ==> 2)
} yield ()

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

for {
 _ <- Match.sKeywords.insert(1, 2, 3, 4)
 _ <- Match.score(median).get.map(_.head ==> 2) // (2 + 3) / 2 = 2.5 rounded down to 2
} yield ()

With decimal numbers this can go wrong:

for {
 _ <- Match.sKeywords.insert(1.0, 2.5, 2.5, 3.0)
 _ <- Match.score(median).get.map(_.head ==> 2) // (2.5 + 2.5) / 2 = 2.5 rounded down to 2 (This is wrong and bug report has been filed)
} yield ()

Attributes

Returns: Value of Attribute type
Source: Keywords.scala
Supertypes: trait AggrCoalesce

trait AggrKw

trait Kw

class Object

trait Matchable

class Any
Show all
Known subtypes: object median.type

Variance of attribute values.

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

for {
 _ <- Match.sKeywords.insert(1, 2, 4)
 _ <- Match.score(stddev).get.map(_.head ==> 1.247219128924647)
} yield ()

Attributes

Returns: Double
Source: Keywords.scala
Supertypes: trait AggrCoalesce

trait AggrKw

trait Kw

class Object

trait Matchable

class Any
Show all
Known subtypes: object stddev.type

Sum of attribute values.

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

for {
 _ <- Match.sKeywords.insert(1, 2, 4)
 _ <- Match.score(sum).get.map(_.head ==> 7)
} yield ()

Attributes

Returns: Value of Attribute type
Source: Keywords.scala
Supertypes: trait AggrCoalesce

trait AggrKw

trait Kw

class Object

trait Matchable

class Any
Show all
Known subtypes: object sum.type

Variance of attribute values.

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

for {
 _ <- Match.sKeywords.insert(1, 2, 4)
 _ <- Match.score(variance).get.map(_.head ==> 1.5555555555555556)
} yield ()

Attributes

Returns: Double
Source: Keywords.scala
Supertypes: trait AggrCoalesce

trait AggrKw

trait Kw

class Object

trait Matchable

class Any
Show all
Known subtypes: object variance.type

attrMarker

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.

for {
 _ <- 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.map(_.sorted ==> List(
   ("Joe", "Coffee", "Ben"),
   ("Liz", "Coffee", "Ben"),
   ("Liz", "Tea", "Ben")
 ))
} yield ()

Attributes

Source: Keywords.scala
Supertypes: trait Kw

class Object

trait Matchable

class Any
Known subtypes: object unify.type

Type members

Classlikes

Attributes

Source: Keywords.scala
Supertypes: trait AggrKw

trait Kw

class Object

trait Matchable

class Any
Known subtypes: trait avg

object avg.type

trait count

object count.type

trait countDistinct

object countDistinct.type

trait median

object median.type

trait stddev

object stddev.type

trait sum

object sum.type

trait variance

object variance.type
Show all

Attributes

Source: Keywords.scala
Supertypes: trait AggrKw

trait Kw

class Object

trait Matchable

class Any
Known subtypes: trait count

object count.type

Attributes

Source: Keywords.scala
Supertypes: trait Kw

class Object

trait Matchable

class Any
Known subtypes: trait AggrCoalesce

trait avg

object avg.type

trait count

object count.type

trait countDistinct

object countDistinct.type

trait median

object median.type

trait stddev

object stddev.type

trait sum

object sum.type

trait variance

object variance.type

trait AggrInt

trait distinct

object distinct.type

trait max

object max.type

trait min

object min.type

trait sample

object sample.type
Show all

Attributes

Source: Keywords.scala
Supertypes: class Object

trait Matchable

class Any
Known subtypes: trait AggrKw

trait AggrCoalesce

trait avg

object avg.type

trait count

object count.type

trait countDistinct

object countDistinct.type

trait median

object median.type

trait stddev

object stddev.type

trait sum

object sum.type

trait variance

object variance.type

trait AggrInt

trait distinct

object distinct.type

trait max

object max.type

trait min

object min.type

trait sample

object sample.type

class maxs

class mins

class samples

trait unify

object unify.type

trait v1

object v1.type
Show all

Attributes

Source: Keywords.scala
Supertypes: class Object

trait Matchable

class Any
Known subtypes: object bi.type

Attributes

Source: Keywords.scala
Supertypes: trait Serializable

trait Product

trait Equals

trait Kw

class Object

trait Matchable

class Any
Show all

Attributes

Source: Keywords.scala
Supertypes: trait Serializable

trait Product

trait Equals

trait Kw

class Object

trait Matchable

class Any
Show all

Attributes

Source: Keywords.scala
Supertypes: trait Serializable

trait Product

trait Equals

trait Kw

class Object

trait Matchable

class Any
Show all

Attributes

Source: Keywords.scala
Supertypes: trait Kw

class Object

trait Matchable

class Any
Known subtypes: object v1.type

In this article

Generated with