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Jethro Larson jethrolarson

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@jethrolarson
jethrolarson / _.template.js
Created January 19, 2012 00:56
Mod of _.template binds `this` to the element passed in, and adds <%@varname%> as a handy shortcut to <%=this.varname%>
//OVERWRITING Underscore.js's templates
// By default, Underscore uses ERB-style template delimiters, change the
// following template settings to use alternative delimiters.
_.templateSettings = {
evaluate : /<%([\s\S]+?)%>/g,
interpolate : /<%=([\s\S]+?)%>/g,
escape : /<%-([\s\S]+?)%>/g
value : /<%@([\s\S]+?)%>/g // inserts value of a variable on the object or "" if undefined
});
@jethrolarson
jethrolarson / reactiveLibraries.md
Last active March 26, 2022 01:14
Reactive Stream Library Comparison

Flyd

https://github.com/paldepind/flyd
License: MIT
Size: 22.4 KB (3.4 KB gzip)
Functions: 16
Project Life: Good
Stars: 1129
Code Quality: Good Functional/Procedural
Comments: JSDoc
Quality Automation: Extensive unit tests, CI

@jethrolarson
jethrolarson / combinators.js
Last active January 15, 2018 19:36
combinators in es6
// [BCKW](https://en.wikipedia.org/wiki/B,C,K,W_system)
// compose
var B = f => g => a => f(g(a))
// flip
var C = f => a => b => f(b)(a)
// Const
var K = a => b => a
@jethrolarson
jethrolarson / string.js
Last active December 22, 2017 22:37
// Take string and get words as an array. Valid split characters are `,` `.` `\s` `/` `\n`
// words :: String -> [String]
export const words = str =>
(str ? str.split(/[\s\n.,/]+/) : []) // split on whitespace
.filter(Boolean);
@jethrolarson
jethrolarson / gist:99ca3c02c0f8c5de85b10843778a580c
Created December 2, 2017 00:57
How moment.js parses falsy values
moment(0) // epoc
moment(undefined) // Now
moment(null) // Invalid Date
moment(false) // throw warning, Invalid date
moment(void 0) // Now
moment('') // Invlid Date
moment([]) // Now
moment({}) // Now
@jethrolarson
jethrolarson / gist:2a28945743668cf828c9eb5a4a924d2f
Created June 21, 2017 23:52
partial.lenses intro
Lenses
======
What is a lens?
---------------
pair of getter and setter that perform immutable updates on parameterized data structure
e.g.
```js
@jethrolarson
jethrolarson / gist:65732a8ba9b4f620b68930923ec3c48a
Created June 21, 2017 22:49
Big O notation for story estimation
O(1) - Trivial, we've done something almost exactly like this and it wont take long to complete at all
O(log n) - Need to add a small capability then it's copy-pasta
O(n) - Simple, It's like things we've done before. No refactoring or architectural changes needed.
O(n^2) - Going to need to rework some things and watch out for regressions
O(n!) - Major rework needed, lots of risk
O(MG) - This is so complex or ill-defined that it may never complete
@jethrolarson
jethrolarson / immutable_update_techniques.js
Last active June 20, 2017 18:21
// Immutable update techniques
// mutate in place
myData.x.y.z = 7;
myData.a.b.push(9);
mydata.a.b[2] = 3;
// clone and mutate
const newData = deepCopy(myData);
newData.x.y.z = 7;
@jethrolarson
jethrolarson / asyncRedux.md
Last active May 10, 2017 22:32
options for async actions in redux

Note: These aren't necessarily mutually exclusive. E.g. we may want to use promise with thunk to get better ergonomics for certain kinds of effects.

Thunk

Learnability: 4
Testability: 4
Happy path: 4
Purity: 2
SLOC: 14

  • Doesn't do a lot for you. Just makes it easy to do async actions
@jethrolarson
jethrolarson / typeSignatures.md
Last active January 27, 2017 23:19
presentation on type signatures in js

Type Signatures for your JS

Y THO

A form of documentation that helps developers understand what a function does.

// toUpper :: String -> String
const toUpper = str => str.toUpperCase()