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<font size="4" face="monospace">OK, so is this really just that that
you are bikeshedding the name? Renaming `input` to `readLine`? <br>
<br>
This is a perfectly reasonable naming choice, of course, but also,
not what you suggested the first time around:<br>
<br>
> ... "a third API" ...<br>
<br>
> ... "there are two feasible directions" ...<br>
<br>
So what exactly are you suggesting?<br>
<br>
<br>
</font><br>
<div class="moz-cite-prefix">On 2/18/2024 5:03 PM, Cay Horstmann
wrote:<br>
</div>
<blockquote type="cite" cite="mid:69a5c417-4f37-4a94-a460-abedb2743791@horstmann.com">Like
I said, either the scanner methods or the console methods are
fine.
<br>
<br>
I am of course aware of the utility/complexity of Scanner, and can
understand the motivation to have a simpler/feebler behavior in
SimpleIO. Like the one in Console.
<br>
<br>
You don't have to "get a console". A SimpleIO.readLine method can
just invoke readLine on the system console.
<br>
<br>
My objection is to add yet another "input" method into the mix.
"input" is weak. Does it read a token or the entire line? Does it
consume the newline? And if it does just what readLine does, why
another method name? Because "input" is three characters fewer?
Let's not count characters.
<br>
<br>
On 18/02/2024 22.43, Brian Goetz wrote:
<br>
<blockquote type="cite">I think you are counting characters and
not counting concepts.
<br>
<br>
Scanner has a ton of complexity in it that can easily trip up
beginners. The main sin (though there are others) is that input
and parsing are complected (e.g., nextInt), which only causes
more problems (e.g., end of line issues.) Reading from the
console is clearly a () -> String operation. The input()
method does one thing, which is get a line of text. That's
simple.
<br>
<br>
Integer.parseInt (or, soon, patterns that match against string
and bind an int) also does one thing: convert a string from
int. It may seem verbose to have to do both explicitly, but it
allows each of these operations to be simple, and it is
perfectly obvious what is going on. On the other hand, Scanner
is a world of complexity on its own.
<br>
<br>
Console::readLine is nice, but first you have to get a Console.
("Why can I print something without having to get some magic
helper object, but I can't do the same for reading?") What
we're optimizing for here is conceptual simplicity; the simplest
possible input method is the inverse of println. The fact that
input has to be validated is a fact of life; we can treat
validation separately from IO (and we should), and it gets
simpler when you do.
<br>
<br>
On 2/18/2024 4:12 PM, Cay Horstmann wrote:
<br>
<blockquote type="cite">I would like to comment on the
simplicity of <a class="moz-txt-link-freetext" href="https://openjdk.org/jeps/8323335">https://openjdk.org/jeps/8323335</a> for beginning
students.
<br>
<br>
I am the author of college texts for introductory programming.
Like other authors, I introduce the Scanner class (and not
Console) for reading user input. Given that students already
know about System.out, it is simpler to call
<br>
<br>
System.out.print("How old are you? ");
<br>
int x = in.nextInt(); // in is a Scanner
<br>
<br>
than
<br>
<br>
int x = Integer.parseInt(console.readLine("How old are you?
"));
<br>
<br>
or with the JEP draft:
<br>
<br>
int x = Integer.parseInt(input("How old are you? "));
<br>
<br>
Then again, having a prompt string is nice too, so I could
imagine using the Console API with Integer.parseInt and
Double.parseDouble, instead of Scanner.nextInt/nextDouble.
<br>
<br>
But why have a third API, i.e. "input"?
<br>
<br>
I think there are two feasible directions. Either embrace the
Scanner API and next/nextInt/nextDouble/nextLine, or the
Console API and readLine. Adding "input" into the mix is just
clutter, and ambiguous clutter at that. At least readLine
makes it clear that the entire line is consumed.
<br>
<br>
Cheers,
<br>
<br>
Cay
<br>
<br>
-- <br>
<br>
Cay S. Horstmann |
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