lazy-tables.core — com.workiva/lazy-tables 0.1.2

aggr clj

(aggr f)

Wraps an aggregate function of the form (fn [acc val]) for application to a table

aggregate clj

(aggregate f table)

Apply an aggregate function to a table. Only applies to tables, not unions or products.

difference clj

(difference & tables)

Create a lazy difference of tables.

FF clj

Vacuously false predicate.

@(select FF tab) === []

in clj

(in equiv & projs)

Create a selection over a projection for use on a lazy-table.

Selects matching values equivalence function equiv after projecting the lazy-tables using the projection conditions. Encodes an equijoin.

=> @(select (in identity :a :b) (product (table [{:a 3 :b 2} {:a 0 :b 0}]) (table [{:a 4 :b 3} {:a 1 :b 1}])))

[({:a 3 :b 2} {:a 4 :b 3})]

p-and clj

(p-and & preds)

Wrap a number of predicates for parallel selection on products. Distributes over union.

(select (par p q) (product xs ys)) ;; equivalent to (product (select p xs) (select q ys))

(select (par p q) (union (product ws xs) (product ys zs)) ;; equivalent to (union (select (par p q) (product ws xs)) (select (par p q) (product ys zs)))

par clj

(par & fs)

Wrap a number of functions for parallel application to products. Distributes over union.

(project (par f g) (product xs ys)) ;; equivalent to (product (project f xs) (project g ys)

(project (par f g) (union (product ws xs) (product ys zs))) ;; equivalent to (union (project (par f g) (product ws xs)) (project (par f g) (product ys za)))

pred clj

(pred f)

Wrap a clojure function in a predicate type -- not typically necessary as the apis all accept Clojure IFns

product clj

(product & tables)

Create a lazy product of tables.

proj clj

(proj f)

Wrap a clojure function in a projection type -- not typically necessary as the apis all accept Clojure IFns.

project clj

(project projection table)

Lazily apply a projection to a table.

s-and clj

(s-and & preds)

Wrap a number of predicates for consecutive selection.

(select (s-and p q) (product xs ys)) ;; equivalent to (select q (select p (product xs ys))

Note that this will force the product before selection.

(select (s-and p q) (union xs ys)) ;; equivalent to (select q (select p (union xs ys))

select clj

(select predicate table)

Lazily apply a selection to a table.

table clj

(table)

(table xs)

Create a lazy-tables table from a clojure sequence

table-empty? clj multimethod

Returns true if the table would evaluate to empty; false if it cannot be determined without evaluation.

TT clj

Vacuously true predicate.

@(select TT table) === @table

union clj

(union & tables)

Create a lazy union of tables