r-k-b

Should help with avoiding errors like:

No version of Cypress is installed in: /home/rkb/.cache/Cypress/6.2.1/Cypress

Please reinstall Cypress by running: cypress install

----------

Cypress executable not found at: /home/rkb/.cache/Cypress/6.2.1/Cypress/Cypress

yoshuawuyts

const Validate = require('form-element/validate')
const State = require('form-element/state')
const Form = require('form-element')
const html = require('bel')

const fields = [
  ['credentials', [
    ['username', 'text', (str) => str.length < 20],
    ['password', 'password', (str) => str.length > 8 && str.length < 99]
  ]],

andymatuschak

A composable pattern for pure state machines with effects

State machines are everywhere in interactive systems, but they're rarely defined clearly and explicitly. Given some big blob of code including implicit state machines, which transitions are possible and under what conditions? What effects take place on what transitions?

There are existing design patterns for state machines, but all the patterns I've seen complect side effects with the structure of the state machine itself. Instances of these patterns are difficult to test without mocking, and they end up with more dependencies. Worse, the classic patterns compose poorly: hierarchical state machines are typically not straightforward extensions. The functional programming world has solutions, but they don't transpose neatly enough to be broadly usable in mainstream languages.

Here I present a composable pattern for pure state machiness with effects,

ekho

CREATE OR REPLACE FUNCTION random_int_array(dim integer, min integer, max integer) RETURNS integer[] AS $BODY$
begin
	return (select array_agg(round(random() * (max - min)) + min) from generate_series (0, dim));
end
$BODY$ LANGUAGE plpgsql;

-- usage example
select random_int_array(15, 6, 40);

-- return example