Quân quan-nh

concept

lexical scope (static scope): dependent only on the program text.
dynamic scope: dependent on the runtime call stack.

clojure

(def x 1) default Var is static, using let for local Var, with-redefs to change the root binding var within its scope (visible in all threads).
(def ^:dynamic x 1) dynamic Var, using binding to change value (thread-local, cannot be seen by any other thread).

In example bellow:

binding only changes the value of *dynamic-var* within the scope of the binding expression

Keybase proof

I hereby claim:

I am quan-nh on github.
I am quannh (https://keybase.io/quannh) on keybase.
I have a public key ASALhdAKTdAZjTn2Os-e4FvnCS5iyEB02SF354Wzw_gpJAo

To claim this, I am signing this object:

Rich Hickey on becoming a better developer

Rich Hickey • 3 years ago

Sorry, I have to disagree with the entire premise here.

A wide variety of experiences might lead to well-roundedness, but not to greatness, nor even goodness. By constantly switching from one thing to another you are always reaching above your comfort zone, yes, but doing so by resetting your skill and knowledge level to zero.

Mastery comes from a combination of at least several of the following:

	import java.time.format.DateTimeFormatter;
	import java.time.Instant;
	import java.time.ZonedDateTime;
	import java.time.ZoneId;
	import java.time.ZoneOffset;

	Instant.now();
	// java.time.Instant = 2015-08-13T09:28:27.141Z

	DateTimeFormatter.ISO_INSTANT.format(Instant.now());