datalevin.built-ins — datalevin 0.9.21

Built-in predicates or functions for Datalog query, i.e. used in q

!= clj

Predicate similar to Clojure not=

* clj

Function similar to Clojure *

+ clj

Function similar to Clojure +

- clj

Function similar to Clojure -

/ clj

Function similar to Clojure /

< clj

Predicate similar to Clojure <

<= clj

Predicate similar to Clojure <=

= clj

Predicate similar to Clojure =

== clj

Predicate similar to Clojure ==

> clj

Predicate similar to Clojure >

>= clj

Predicate similar to Clojure >=

aggregate-avg clj

(aggregate-avg coll)

aggregates clj

and clj

Predicate that is similar to Clojure and e.g. [(and (= ?g "f"") (like ?n "A%""))]

array-map clj

Function similar to Clojure array-map

avg clj

Aggregation function that calculates the average.

compare clj

Function similar to Clojure compare

complement clj

Function similar to Clojure complement

contains? clj

Function similar to Clojure contains?

count clj

Function similar to Clojure count

count-distinct clj

(count-distinct coll)

Aggregation function that count the distinctive values of a collection.

dec clj

Function similar to Clojure dec

distinct clj

(distinct coll)

Aggregation function that returns the distinctive values of a collection.

empty? clj

Function similar to Clojure empty?

even? clj

Predicate similar to Clojure even?

false? clj

Predicate similar to Clojure false?

fulltext clj

(fulltext db query)

(fulltext db arg1 arg2)

(fulltext db arg1 arg2 arg3)

Function that does fulltext search. Returns matching datoms in the form of [e a v] for convenient vector destructuring.

The last argument of the 4 arity function is the search option map. See [[datalevin.core.search]].

When neither an attribute nor a :domans is specified, a full DB search is performed.

For example:

• Full DB search: [(fulltext $ "red") [[?e ?a ?v]]]

• Attribute specific search: [(fulltext $ :color "red") [[?e ?a ?v]]]

• Domain specific search:

  [(fulltext $ "red" {:domains ["color"]} [[?e ?a ?v]])]

get clj

Function similar to Clojure get

get-else clj

(get-else db e a else-val)

Function. Return the value of attribute a of entity e, or else-val if it doesn't exist. e.g. [(get-else $ ?a :artist/name "N/A") ?name]

get-some clj

(get-some db e & as)

Function. Takes a DB, an entity, and one or more cardinality one attributes, return a tuple of the first found attribute and its value. e.g. [(get-some $ ?e :country :artist :book) [?attr ?val]]

ground clj

Function. Same as Clojure identity. E.g. [(ground [:a :e :i :o :u]) [?vowel ...]]

hash-map clj

Function similar to Clojure hash-map

identical? clj

Predicate similar to Clojure identical?

identity clj

Function similar to Clojure identity

in clj

(in input coll)

(in input coll not?)

Predicate similar to IN in SQL, e.g. [(in ?name ["Smith" "Cohen" "Doe"])]

inc clj

Function similar to Clojure inc

keyword clj

Function similar to Clojure keyword

like clj

(like input pattern)

(like input pattern opts)

(like input pattern {:keys [escape]} not?)

Predicate similar to LIKE in SQL, e.g. [(like ?name "%Smith")]

list clj

Function similar to Clojure list

max clj

function similar to Clojure max

median clj

Aggregation function that calculates the median.

meta clj

Function similar to Clojure meta

min clj

Function similar to Clojure min

missing? clj

(missing? db e a)

Predicate that returns true if the entity has no value for the attribute in DB e.g. [(missing? $ ?e :sales)]

mod clj

Function similar to Clojure mod

name clj

Function similar to Clojure name

namespace clj

Function similar to Clojure namespace

neg? clj

Predicate similar to Clojure neg?

nil? clj

Predicate similar to Clojure nil?

not clj

Predicate similar to Clojure not

not-empty clj

Function similar to Clojure not-empty

not-in clj

(not-in input coll)

Predicate similar to NOT IN in SQL, e.g. [(not-in ?name ["Smith" "Cohen" "Doe"])]

not-like clj

(not-like input pattern)

(not-like input pattern opts)

Predicate similar to NOT LIKE in SQL, e.g. [(no-like ?name "%Smith")]

not= clj

Predicate similar to Clojure not=

odd? clj

Predicate similar to Clojure odd?

or clj

Predicate that is similar to Clojure or e.g. [(or (= ?g "f"") (like ?n "A%""))]

pos? clj

Predicate similar to Clojure pos?

print-str clj

Function similar to Clojure print-str

println-str clj

Function similar to Clojure println-str

prn-str clj

Function similar to Clojure prn-str

query-fns clj

quot clj

Function similar to Clojure quot

rand clj

Function similar to Clojure rand

rand-int clj

Function similar to Clojure rand-int

range clj

Function similar to Clojure range

re-find clj

Function similar to Clojure re-find

re-matches clj

Function similar to Clojure re-matches

re-pattern clj

Function similar to Clojure re-pattern

re-seq clj

Function similar to Clojure re-seq

rem clj

Function similar to Clojure rem

sample clj

(sample n coll)

Aggregation function that randomly sample from a collection.

set clj

Function similar to Clojure set

some? clj

Predicate similar to Clojure some?

stddev clj

Aggregation function that calculates the stddev.

str clj

Function similar to Clojure str

subs clj

Function similar to Clojure subs

sum clj

Aggregation function that adds up collection

true? clj

Predicate similar to Clojure true?

tuple clj

Function similar to Clojure vector

type clj

Function similar to Clojure type

untuple clj

Function similar to Clojure identity

variance clj

Aggregation function that calculates the variance.

vec-neighbors clj

(vec-neighbors db query)

(vec-neighbors db arg1 arg2)

(vec-neighbors db arg1 arg2 arg3)

Function that does vector similarity search. Returns matching datoms in the form of [e a v] for convenient vector destructuring.

The last argument of the 4 arity function is the search option map. See [[datalevin.core.search-vec]].

When neither an attribute nor a :domains is specified, an exception will be thrown.

For example:

• Attribute specific search: [(vec-neighbors $ :color ?query-vec) [[?e ?a ?v]]]

• Domain specific search: [(vec-neighbors $ ?query-vec {:domains ["color"]} [[?e ?a ?v]])]

vector clj

Function similar to Clojure vector

zero? clj

Predicate similar to Clojure zero?