gordonbrander

// Splice in a string between `begin` and `end` indexes.
// Returns a new string.
function spliceString(string, insert, begin, end) {
  return string.slice(0, begin) + insert + string.slice(end);
}

// Search a string with a regular expression, where `step` callback will
// be called at each match, allowing you to perform extra logic and create a
// replacement string.
//

gordonbrander

// Hashtext: the no-markup markup language.
// Quick-and-dirty Twitter-style text rendering.
//
// * Auto-paragraphatize and linebreak newlines.
// * Auto-link URLs (and prettify them, too).
// * Expand #hashtags into something useful (your choice).
//
// Copyright (c) 2014 Gordon Brander.
// Released under the MIT license http://opensource.org/licenses/MIT.
//

gordonbrander

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
Pull structured content out of the DOM.

- Hero images
- Title
- Summary

gordonbrander

const reduce = Array.reduce;

// Call function `f` with value `x`.
const callWith = (x, f) => f(x);

// Pipe value `x` through many single-argument functions in succession.
// This is kind of like a Unix pipe. The value of the previous function is
// passed to the next function, etc. Note that functions are called
// from left-to-right, with left being first.
export const pipe = (x, ...f) => reduce(f, callWith, x);

gordonbrander

// Create a finite state switching function.
// Given a list of states, returns a function that will take a `prev` state
// and `next` state and will only advance state to `next` if it is one of
// the defined states.
const states = (...states) => (prev, next) =>
  states.indexOf(next) !== -1 ? next : prev;

gordonbrander

/*
Automatically namespace all CSS selectors.
Eliminates most problems with style leak

    .active {}

...becomes

    .button-active {}
*/

gordonbrander

export const progress = (t, start, end) =>
  t < start ? 0 :
  t > end ? 1 :
  (t / (end - start));

export const tween = (start, end, step, state, t) =>
  step(state, progress(t, start, end));

export const event = (time, step, state, t) =>
  t < time ? step(state, 0) : step(state, 1);

gordonbrander

// A message bus. Dispatches messages to `receive` in order (FIFO).
const Bus = (receive) => {
  var isDraining = false;
  const queue = [];

  // Define a function to send a message to the queue.
  const send = (msg) => {
    queue.push(msg);
    // If we're not already draining the queue, start draining.
    // We only want to kick this loop off once, since send can be called

gordonbrander

export const $$ = (selector) => document.querySelector(selector);
export const $ = (selector) => document.querySelectorAll(selector);

// Apply a side effect to `n` items.
export const sets = (f, n, ...rest) => {
  for (var i = 0; i < n.length; i++) f(n[i], ...rest);
}

export const toggleClass = (el, classname, isAdding) =>
  isAdding ? el.classList.add(classname) : el.classList.remove(classname);

gordonbrander

export const Spring = (x, y, mass, stiffness, viscosity) => ({
  prevX: x,
  prevY: y, 
  currX: x,
  currY: y,
  mass, stiffness, viscosity
});

Spring.copy = (spring) => ({
  prevX: spring.prevX,