From 3cb37e0ca8705375419df0b67d84cbbeb2e54311 Mon Sep 17 00:00:00 2001
From: Colin Meinke <hello@colinmeinke.com>
Date: Thu, 14 Sep 2017 18:30:30 -0500
Subject: [PATCH] fix(performance): reduce object creation

Refs colinmeinke/wilderness#71
---
 src/clone.js            | 17 +++++++++++++----
 src/color-middleware.js |  4 +++-
 src/frame.js            | 33 +++++++++++++++++----------------
 src/middleware.js       | 36 +++++++++++++++++++++++++++---------
 4 files changed, 60 insertions(+), 30 deletions(-)

diff --git a/src/clone.js b/src/clone.js
index 4238bc8..51b7ae6 100644
--- a/src/clone.js
+++ b/src/clone.js
@@ -10,12 +10,21 @@
  */
 const clone = value => {
   if (Array.isArray(value)) {
-    return value.map(x => clone(x))
+    const arr = []
+
+    for (let i = 0, l = value.length; i < l; i++) {
+      arr.push(clone(value[ i ]))
+    }
+
+    return arr
   } else if (value !== null && typeof value === 'object') {
-    return Object.keys(value).reduce((obj, key) => {
+    const obj = {}
+
+    for (let key in value) {
       obj[ key ] = clone(value[ key ])
-      return obj
-    }, {})
+    }
+
+    return obj
   }
 
   return value
diff --git a/src/color-middleware.js b/src/color-middleware.js
index 9e5582b..4d8ede9 100644
--- a/src/color-middleware.js
+++ b/src/color-middleware.js
@@ -163,6 +163,8 @@ const htmlColors = {
   'yellowgreen': '#9ACD32'
 }
 
+const htmlColorKeys = Object.keys(htmlColors)
+
 /**
  * Converts a color string to a Color.
  *
@@ -253,7 +255,7 @@ const rgb = str => str.startsWith('rgb(')
  * @example
  * html('limegreen')
  */
-const html = str => Object.keys(htmlColors).indexOf(str) !== -1
+const html = str => htmlColorKeys.indexOf(str) !== -1
 
 /**
  * Converts a hex string to a Color.
diff --git a/src/frame.js b/src/frame.js
index eeb5d5c..c8f9520 100644
--- a/src/frame.js
+++ b/src/frame.js
@@ -248,11 +248,7 @@ const frame = (timeline, at) => {
 
     const shapePosition = (timeline.state.position - start) / (finish - start)
 
-    return frameShapeFromShape({
-      shape,
-      position: shapePosition,
-      middleware: timeline.middleware
-    })
+    return frameShapeFromShape(shape, shapePosition, timeline.middleware)
   })
 }
 
@@ -306,19 +302,18 @@ const frameShapeFromPlainShapeObject = ({ shapes: childPlainShapeObjects, ...pla
 /**
  * Creates a FrameShape from a Shape given the Position.
  *
- * @param {Object} opts
- * @param {Middleware[]} opts.middleware
- * @param {Position} opts.position
- * @param {Shape} opts.shape
+ * @param {Shape} shape
+ * @param {Position} position
+ * @param {Middleware[]} middleware
  *
  * @returns {FrameShape}
  *
  * @example
- * frameShapeFromShape({ position: 0.75, shape })
+ * frameShapeFromShape(shape, 0.75, [])
  */
-const frameShapeFromShape = ({ middleware = [], position, shape }) => {
-  const fromIndex = shape.keyframes.reduce((currentFromIndex, { position: keyframePosition }, i) => (
-    position > keyframePosition ? i : currentFromIndex
+const frameShapeFromShape = (shape, position, middleware) => {
+  const fromIndex = shape.keyframes.reduce((currentFromIndex, keyframe, i) => (
+    position > keyframe.position ? i : currentFromIndex
   ), 0)
 
   const toIndex = fromIndex + 1
@@ -442,7 +437,13 @@ const tween = (from, to, easing, position) => {
       throw new TypeError(errorMsg)
     }
 
-    return from.map((f, i) => (tween(f, to[ i ], easing, position)))
+    const arr = []
+
+    for (let i = 0, l = from.length; i < l; i++) {
+      arr.push(tween(from[ i ], to[ i ], easing, position))
+    }
+
+    return arr
   } else if (from !== null && typeof from === 'object') {
     if (to !== null && typeof to !== 'object') {
       throw new TypeError(errorMsg)
@@ -450,9 +451,9 @@ const tween = (from, to, easing, position) => {
 
     const obj = {}
 
-    Object.keys(from).map(k => {
+    for (let k in from) {
       obj[ k ] = tween(from[ k ], to[ k ], easing, position)
-    })
+    }
 
     return obj
   } else if (typeof from === 'number') {
diff --git a/src/middleware.js b/src/middleware.js
index db325ea..94bad04 100644
--- a/src/middleware.js
+++ b/src/middleware.js
@@ -23,15 +23,21 @@ const apply = (value, func) => {
   const v = func(value)
 
   if (Array.isArray(v)) {
-    return v.map(x => apply(x, func))
+    const arr = []
+
+    for (let i = 0, l = v.length; i < l; i++) {
+      arr.push(apply(v[ i ], func))
+    }
+
+    return arr
   }
 
   if (v !== null && typeof v === 'object') {
     const obj = {}
 
-    Object.keys(v).map(k => {
+    for (let k in v) {
       obj[ k ] = apply(v[ k ], func)
-    })
+    }
 
     return obj
   }
@@ -50,9 +56,15 @@ const apply = (value, func) => {
  * @example
  * input({ foo: 1, bar: [ 2, 3 ] }, middleware)
  */
-const input = (value, middleware) => middleware.reduce((v, m) => (
-  apply(v, m.input)
-), value)
+const input = (value, middleware) => {
+  let v = value
+
+  for (let i = 0, l = middleware.length; i < l; i++) {
+    v = apply(v, middleware[ i ].input)
+  }
+
+  return v
+}
 
 /**
  * Runs each Middleware output function in reverse on a value.
@@ -65,8 +77,14 @@ const input = (value, middleware) => middleware.reduce((v, m) => (
  * @example
  * output({ foo: 1, bar: [ 2, 3 ] }, middleware)
  */
-const output = (value, middleware) => [ ...middleware ].reverse().reduce((v, m) => (
-  apply(v, m.output)
-), value)
+const output = (value, middleware) => {
+  let v = value
+
+  for (let i = middleware.length - 1; i >= 0; i--) {
+    v = apply(v, middleware[ i ].output)
+  }
+
+  return v
+}
 
 export { input, output }