Caladan

(Proposed) API

PSA: Literally none of this has been implemented

I/O

Read from CSV:

(table-from-csv "foo.csv")

Read from SQL:

(table-from-sql "select foo, bar from baztable;" sqlconn)

Data Manipulation

Take n values from table

(take table 10)

Slice table

(slice table 5 10)

Get distinct values for given columns (or the whole table)

;; Returns a new table (two cols wide) with distinct values from col1 and col2
(distinct table [:col1 :col2])

;; Returns distinct (unique) rows for the entire table
(distinct table)

Sort values for given vector of cols

(sort table {:col1 #(sortfunc)} :type :asc])

Filter values where a predicate is matched

(filter table {:col1 #(= % "foo") :col2 #{1 2}})

Apply a function on columns

(apply table {:col1 #(* 4 %) :col2 #(str % "_appender")})

Potentially: Apply a function with logic on multiple cols (apply (fn :col1 :col2))

Reduce columns

;; This will probably return a map of {:col reduced_value}?
(reduce table {:col1 + :col2 #(+ %1 %2 2)})

Select columns

(select table [:col1 :col2])

Group a table. This will return a map of group keys to...new tables?

(groupby table [:col1])
{:foo-group <Table> :bar-group <Table>}

Join two tables

(left-join table1 table2 :on [:col1])
(right-join table1 table2 :on [:col1])
(inner-join table1 table2 :on [:col1 :col2])
(outer-join table1 table2 :on [:col2])

Set operations

(intersect table1 table2)
(union table1 table2)
(diff table1 table2)

Compose a pipeline of operations:

(c<- table
     (filter {:col1 #{1}})
     (groupby [:col2])
     (reduce {:col1 +}))

Equivalent to

select sum(col1)
from table
where col1 = 1
groupby col2;