javascript - get positions of given elements in a 2d array in Ramda -

i have array data, ie.

const data = [[   , '+',    ],               ['+',    , '+'],               [   ,    , '+']] 

i'd [x, y] coordinates of every element '+':

const expected = [[1, 0], [0, 1], [2, 1], [2, 2]] 

how can in ramda?

i knocked out code works:

const gethorizontalposition = r.map(r.addindex(r.reduce)   ( (xs, el, idx) => r.equals('+', el) ? r.append(idx, xs) : xs, [] ))  const combinewithverticalposition = r.addindex(r.chain)   ( (xs, y) => r.map( (x) => [x, y] )(xs) )  pipe(gethorizontalposition,      combinewithverticalposition)(data) 

but, can see, it's ugly , not readable. how can more elegantly?

link code in ramda repl

as may have noticed, ramda not index handling. can't come particularly nice solution.

something work, seems less elegant 2 reducers 1 mentioned in comment:

pipe(addindex(map)((xs, i) => pipe(   map(equals('+')),    addindex(map)((x, j) => x && [i, j]),    reject(equals(false)) )(xs)), unnest)(data) 

you can see on ramda repl.