Laurence Chen humorless

When to use `assert`?

In JVM Clojure, Exceptions are for operating errors ("something went wrong") and Assertions are for programmer and correctness errors ("this program is wrong").

An assert might be the right tool if throwing an Exception isn't enough. Use them when the assertion failing means

there's a bug in this program (not a caller)
what happens next is undefined

推斷 niche market

從網路上現存的資訊，分析 {公司官方網站} 這家公司。

{公司名稱} 是什麼細分市場的領導者？

推斷 value proposition

Duration

(time/duration dur-str)

ZoneId type

(def event-time-zone (java.time.ZoneId/of "Europe/Brussels"))

Modern data stack

Main features

REPLWARE 建議的資料分析技術棧 (modern data stack) 主要有下列特色：

ELT over ETL
SQL based analytics over non-SQL based analytics
Analytic Engineer as a new position
When the data is not exceeding 1T, your desktop/notebook is fast enough.

為什麼要用 Clojure 語言來開發軟體？

在 Clojure 社群的一個說法：「同樣的工程師使用 Java 來開發軟體、使用 Nodejs 來開發軟體、使用 Clojure 來開發同樣軟體所花費的時間，大約是：5:3:1。」

Part 1: Basic

lesson 1: syntax

truth, math, string
Intros to list, vector, map, set
conj: conj list ,conj vector ,conj map ,conj set

invoke function

SPC SPC = M-x
- load-theme
- add-project
- global-linum-mode

special commands

Create gh-pages branch

git checkout --orphan gh-pages
git rm -rf .    # 砍掉所有檔案重來
...  # 加新檔案
git add .
git commit -m 'create new branch'

Push this branch to github repo

	;; Logging is a bit of a lost art. I see people use it the same way they use
	;; println debugging, putting in lots of (log/debug "HERE") kind of stuff, and
	;; then removing it afterwards.
	;;
	;; But with a good logging library these logging statements can continue to
	;; provide value, even if (especially if) most of the time you turn them off.
	;; For this you need to make good use of log levels like
	;; error/warn/info/debug/trace. What follows is an illustrated example of how I
	;; tend to use them.

	(ns my-backend.core
	(:gen-class)
	(:require [compojure.core :as c]
	[compojure.route :as route]
	[ring.adapter.jetty :as jetty]
	[ring.middleware.defaults :as ring-defaults]
	[hiccup2.core :as h]
	#_[muuntaja.core :as m]
	[muuntaja.middleware :as muuntaja]))

	(ns my-backend.core
	(:gen-class)
	(:require [compojure.core :as c]
	[compojure.route :as route]
	[ring.adapter.jetty :as jetty]
	[ring.middleware.defaults :as ring-defaults]
	[hiccup2.core :as h]
	#_[muuntaja.core :as m]
	[muuntaja.middleware :as muuntaja]))