calopez

# frozen_string_literal: true

module Tesseract
  module Transaction
    module Steps
      # Executes the step in a background job. Argument is either an ActiveJob
      # or another Transaction (or anything that implements `#perform_later`.
      #
      # If the provided transaction implements a `validate` step, then that
      # validator will be called on the input before the job is enqueued. This

calopez

http://stackoverflow.com/questions/22667401/postgres-json-data-type-rails-query
http://stackoverflow.com/questions/40702813/query-on-postgres-json-array-field-in-rails

#payload: [{"kind"=>"person"}]
Segment.where("payload @> ?", [{kind: "person"}].to_json)

#data: {"interest"=>["music", "movies", "programming"]}
Segment.where("data @> ?",  {"interest": ["music", "movies", "programming"]}.to_json)
Segment.where("data #>> '{interest, 1}' = 'movies' ")
Segment.where("jsonb_array_length(data->'interest') > 1")

calopez

Keybase proof

I hereby claim:

• I am calopez on github.
• I am karloslopez (https://keybase.io/karloslopez) on keybase.
• I have a public key ASAgUhfQW56OTgbSiCtz4tBVkUyGxO2ErCmbjpoQL-d7JQo

To claim this, I am signing this object:

calopez

-- Retrieve descendants
-- ====================
-- retrieve descendants of #4
SELECT c.*
  FROM Comments AS c
    JOIN TreePaths AS t ON c.comment_id = t.descendant
 WHERE t.ancestor = 4;


-- Retrieve ancestors

calopez

After automatically updating Postgres to 10.0 via Homebrew, the pg_ctl start command didn't work.
The error was "The data directory was initialized by PostgreSQL version 9.6, which is not compatible with this version 10.0."

Database files have to be updated before starting the server, here are the steps that had to be followed:

# need to have both 9.6.x and latest 10.0 installed, and keep 10.0 as default
brew unlink postgresql
brew install postgresql@9.6
brew unlink postgresql@9.6
brew link postgresql

calopez

%% Based on code from
%%   Erlang Programming
%%   Francecso Cesarini and Simon Thompson
%%   O'Reilly, 2008
%%   http://oreilly.com/catalog/9780596518189/
%%   http://www.erlangprogramming.org/
%%   (c) Francesco Cesarini and Simon Thompson

-module(frequency).
-export([start/0,allocate/0,deallocate/1,stop/0]).

calopez

%% Based on code from
%%   Erlang Programming
%%   Francecso Cesarini and Simon Thompson
%%   O'Reilly, 2008
%%   http://oreilly.com/catalog/9780596518189/
%%   http://www.erlangprogramming.org/
%%   (c) Francesco Cesarini and Simon Thompson

-module(frequency).
-export([init/0]).

calopez

-module(palin).
-export([
         palin/1,
         nopunct/1,
         palindrome/1,
         client/0,
         server/0
]).

% palindrome problem

calopez

-module(sort).
-export([qsort/1, test/0]).
-include_lib("eunit/include/eunit.hrl").

qsort([])        -> [];
qsort([X1|Xs])   -> qsort(Xs, X1).
qsort(L, Pivot)  -> qsort(left(L, Pivot)) ++ [Pivot] ++ qsort(right(L, Pivot)).


right(L, Pivot) -> [X || X <- L, X  > Pivot].

calopez

-module(hof).
-export([
         compose/1,
         iterate/1,
         twice/1,
         test/0
        ]).
-include_lib("eunit/include/eunit.hrl").

compose([Fi|Fs])      -> fun(Arg) -> Fi(compose(Fs, Arg)) end.