Scala, Java, Unix, MacOS tutorials (page 65)

The trouble with names

For the last several days in dreamland I’ve been working in a large, beautiful log cabin. Along with a group of cohorts — I can’t call them coworkers — we’ve been giving a series of presentations to a group of visitors.

Before my presentation this morning I went out into the audience to talk to a couple of people I had recently met. They were talking about their plans for next weekend, and invited me to join them on Saturday.

Just after this I turned around and saw that one of my cohorts had scribbled a large collection of new notes on my blackboard. Yes, a blackboard with chalk, not a whiteboard with markers. I would later think about this, and wonder if it was influenced by a Columbo episode I watched recently — the one about the architect who likes classical music and kills the millionaire cowboy who likes country-western music. The architect also teaches at a local college, and he and Columbo spent several minutes wiping off chalkboards during one scene.

So I walk up to this cohort who has written notes all over my chalkboards like a mad scientist. I read what he has written, and he asks, “What do you think?”

A “CliffsNotes” app

These days I’m pretty consistent in how I take notes when reading an online article or blog post, so I’m writing a little “CliffsNotes” app to make that process faster. The basic app consists of a browser on the left, and some controls at the bottom of it so I can rapidly put notes in the notepad on the right.

A motel in Haines, Alaska

I’ve been stuffing receipts and junk into a compartment in my car for years, and cleaned it out yesterday. This card is by far the best thing I found in there (find Haines, AK on a map, and you might know why). As I’m shredding things, I just saw that on this day two years ago I was in Virginia Beach.

A Scala method to run any block of code slowly

The book, Advanced Scala with Cats, has a nice little Scala function you can use to run a block of code “slowly”:

def slowly[A](body: => A): A = 
    try
        body
    finally
        Thread.sleep(100)

I’d never seen a try/finally block written like that (without a catch clause), so it was something new for the brain.

In the book they run a factorial method slowly, like this:

slowly(factorial(n - 1).map(_ * n))

FWIW, you can modify slowly to pass in the length of time to sleep, like this:

def slowly[A](body: => A, sleepTime: Long): A =
    try
        body
    finally
        Thread.sleep(sleepTime)

Scala: How to capitalize every word in a string

As a brief tip, here’s an example of how to capitalize every word in a string in Scala:

"foo bar baz".split(" ").map(_.capitalize).mkString(" ")

The output of that expression is:

Foo Bar Baz

Also, instead of using the underscore character inside of map, you can write that anonymous function like this, if you prefer:

"foo bar baz".split(" ").map(s => s.capitalize).mkString(" ")

If you wanted to see how to capitalize every word in a Scala string, I hope that’s helpful. Also, if the map method doesn’t make any sense to you, check out my How to write a 'map' function in Scala lesson.

JavaFX TextArea: How to insert text at the cursor/caret position

JavaFX TextArea FAQ: How do I insert a string/text into a TextArea at the cursor/caret position?

Solution: First get the position of the cursor/caret in the TextArea, then insert your new text at that position:

int caretPosition = notesTextArea.getCaretPosition;
notesTextArea.insertText(caretPosition, "My new text");

JavaFX: How to set minimum dialog width/size

JavaFX tip: To set the minimum width of a dialog, such as a TextInputDialog, use the setMinWidth method on the dialog’s dialog pane, like this:

val d = new TextInputDialog("")
d.setTitle("Open URL")
d.setHeaderText("Open a URL")
d.getDialogPane.setMinWidth(500)  <-- solution

Scala: How to create JavaFX keystroke handlers/listeners on a Scene/Stage

As a brief note, here are a few examples of how I add some keystroke handlers/listeners to a JavaFX project written in Scala:

// add keystroke listeners/handlers to the scene
def addKeystrokeHandlers(scene: Scene, stage: Stage, theMainPane: MainSplitPane): Unit = {
    configureCommandMHandler(scene, stage)
    // other code was here ...
}

// Minimize (needed to implement manually)
private def configureCommandMHandler(scene: Scene, mainStage: Stage): Unit = {
    val keyComboCommandM: KeyCombination = new KeyCodeCombination(
        KeyCode.M,
        KeyCombination.META_DOWN
    )
    scene.addEventHandler(KeyEvent.KEY_RELEASED, (event: KeyEvent) => {
        if (keyComboCommandM.`match`(event)) {
            mainStage.setIconified(true)
        }
    })
}

True emptiness is before thinking

I wasn’t able to take any pictures of them, but last week we had some beautiful full Moon sunsets over the Rocky Mountains. Then I just came across this photo of the Moon and some mountains, with this “true emptiness” quote by Zen Master Seung Sahn. (The image comes from this link.)

RIP, Dolores O’Riordan

My phone says I have 18 songs by the Cranberries and Dolores O’Riordan. Some of the favorites are Zombie, Linger, Dreams, Electric Blue, and War Child. RIP, Ms. O’Riordan.

~ January 15, 2018

Original nature, simply stated

In Jason Quinn’s Inka Speech he describes “original nature” very clearly. When you find the mind before thinking, you find Zen.

For more information, see Zen Master Seung Sahn’s books. I highly recommend Dropping Ashes on the Buddha, and Only Don’t Know. They are both as clear as any Zen books you will ever read.

You have to “let go”

In meditation practice you come to a point where you have to “let go.” It’s easy for me to do this at night, I’m usually tired and there isn’t any resistance, but it’s 1,000 times harder during the day. I’ve done it a few times for brief periods and the experience is really remarkable, but I haven’t been able to sustain it yet. No telling what happens when I can sustain it.

~ a note from May 22, 2015

Meditation leads to concentration

In other blog posts I've mentioned that I think meditation can be a great tool for improving your concentration, so I thought I'd take a few moments here to explain how to meditate. It comes very naturally to me these days, but if you've never meditated before you may not know how to get started, so I thought I'd share this very simple technique here.

How to meditate

This is the very simple technique I learned when I first started meditating. Even in Zen schools, meditation is very simple. The secret is in the daily practice, the repetition that builds the new neural connections in your brain.

Shunryu Suzuki: Keep your doors open

This is a quote from one of my favorite Zen Masters, Shunryu Suzuki: “(In meditation) Leave your front door and your back door open. Let your thoughts come and go. Just don’t serve them tea.” Image from this Tumblr page.

“Low self esteem is the root cause of practically all the pain and misery in the world”

“Low self-esteem is the root cause of practically all the pain and misery in the world. It’s what drives war, and torture, and genocide. It’s what evil is. Do you think Hitler liked himself? Or Cortez? We hate others because we hate ourselves.”

~ Leonard, on Northern Exposure

“I simply did myself”

“I would say I outdid myself, but I’m always this good. So I simply did myself.”

~ Tahani

The wild horses of the Sand Wash Basin

Still on my bucket list, thanks to meeting a native American shaman several years ago: See the wild horses of the Sand Wash Basin. (Thanks to the AAA magazine for this reminder.)

Love at the Five and Dime, Nanci Griffith

The prettiest song I’ve heard in quite a while: Love at the Five & Dime, by Nanci Griffith.

(I thought maybe I knew this song from the 1970s, but it wasn’t released until 1986, so maybe it was a Texas thing.)

Our Town, by Iris DeMent

And you know the sun’s settin’ fast
And just like they say nothing good ever lasts
Well, go on now and kiss it goodbye but hold on to your lover
’Cause your heart’s bound to die
Go on now and say goodbye to our town, to our town
Can’t you see the sun’s settin’ down on our town, on our town
Goodnight

~ from the song Our Town, by Iris DeMent
(and known by NX fans)

What is a “context parameter” in Scala 3 (Dotty)?

The current Dotty (Scala 3) documentation uses the term context parameter in many places, but I haven’t seen a formal definition of it anywhere. After a little bit of research, here’s a Dotty “context parameter” definition that I pieced together from several different pages: