If I have my druthers, I’ll finish writing my current book near this wonderful spot, somewhere in Alaska.
The funny thing about writing the Scala Cookbook is that it started as a whim. I was just about to leave for a vacation at the beach, and right before I turned off the computer, a thought flashed in my mind, “I should contact the people at O’Reilly about writing a cookbook for Scala.” I then had a doubt that they would actually do it, but I applied the “What the heck” rule — i.e., “What the heck, what do I have to lose?” — and sent the email.
I dug around the internet for a few minutes, found the correct O’Reilly email address, sent them a message, turned off the computer, and drove to the beach. While I was at the beach the publisher wrote and said, “Love it, send me a full proposal!”
So if you’re thinking about doing something, but are afraid or uncertain about doing it ... apply the “What the heck” rule, and give it a shot. :)
Without much introduction or discussion, here’s a Scala example that shows how to read from one text file while simultaneously writing the uppercase version of the text to a second output file:
As shown in the image, I’ve finally come to the realization that I can’t write a book. But I can write a few sentences, and then a few pages, and eventually a chapter on a given topic. And then I can write another chapter, and then another. But to sit down and say, “I’m going to write a book,” no, that’s too hard.
“The best work that anybody ever writes is the work that is on the verge of embarrassing him, always.” Good advice on writing from Arthur Miller, via the Twitter account of Jon Winokur.
This is an excerpt from the Scala Cookbook (partially modified for the internet). This is Recipe 12.3, “How to read and write binary files in Scala.”
You want to read data from a binary file or write data to a binary file.
Scala doesn’t offer any special conveniences for reading or writing binary files, so use the Java
This is an excerpt from the Scala Cookbook (partially modified for the internet). This is Recipe 12.2, “How to write text files in Scala.”
You want to write plain text to a file, such as a simple configuration file, text data file, or other plain-text document.
Scala doesn’t offer any special file writing capability, so fall back and use the Java
I was working with Android Preferences recently, and after writing a few “save my preference” methods, I decided to take a few minutes to organize my code and put all of those Preference methods in a PreferenceUtils class. I made the methods static, and following functional programming principles, I made their output depend only on their input, so they require you to pass in a
Context reference, along with your preference key and value.
I’m currently writing a complicated Linux bash shell script where I need to keep a counter in an external file, and to do so, I need to be able to write to a file and then read from that file.
In short, this is how I write my counter to that file:
# create a variable to represent the filename COUNTER_FILE="counter.tmp" # write to the file echo "0" > $COUNTER_FILE
Later in the code I increment the counter and write it to the file like this:
Problem: You want to write XML data to a file in a Scala application, such as saving application data or configuration information to a file.
scala.xml.XML.save method to write a Scala literal to a file. Given this XML literal: