Elseif v. elsif?

ruby-talk
1

What the?? I just spent two days trying to figure out why I couldn't
reproduce the example in "Ruby in 20 minutes" and get it to work. After
examining my code line for line against the example code and not being
able to detect any error, I was assembling several code examples into a
text file to post here, when I happened to notice 'elsif'. Why
didn't Ruby flag 'elseif' as an error?

Does Ruby try differentiate itself in ridiculous ways like that just for
the sake of being different? And why isn't something like that
explicitly pointed out in a beginning tutorial? So far, I have to give
Ruby two thumbs down.

C++, Java, Javascript, php, Servlets+JSP programmer

···

--
Posted via http://www.ruby-forum.com/.

2

Ruby isn't the only language that does that.

"Different" would be more like the way bash does it: "elif"

···

On Wed, Mar 07, 2007 at 05:56:56PM +0900, 7stud 7stud wrote:

Does Ruby try differentiate itself in ridiculous ways like that just for
the sake of being different? And why isn't something like that
explicitly pointed out in a beginning tutorial? So far, I have to give
Ruby two thumbs down.

--
CCD CopyWrite Chad Perrin [ http://ccd.apotheon.org ]
"There comes a time in the history of any project when it becomes necessary
to shoot the engineers and begin production." - MacUser, November 1990

3

What the?? I just spent two days trying to figure out why I couldn't
reproduce the example in "Ruby in 20 minutes" and get it to work. After
examining my code line for line against the example code and not being
able to detect any error, I was assembling several code examples into a
text file to post here, when I happened to notice 'elsif'. Why
didn't Ruby flag 'elseif' as an error?

Because it nvere sees it :frowning:

Look at two examples

if true then
   whatever
   elseif
end

now elsif is seen as an undefined method but

if false then
  whatever
  elseif
end

whatever and elseif are not evaluated.

I strongly advice you to use a syntax highlighting ediotr like e.g.
vim, emacs, Jedit, geany and tons of others.

Cheers
Robert

···

On 3/7/07, 7stud 7stud <dolgun@excite.com> wrote:

Does Ruby try differentiate itself in ridiculous ways like that just for
the sake of being different? And why isn't something like that
explicitly pointed out in a beginning tutorial? So far, I have to give
Ruby two thumbs down.

C++, Java, Javascript, php, Servlets+JSP programmer

--
Posted via http://www.ruby-forum.com/\.

--
We have not succeeded in answering all of our questions.
In fact, in some ways, we are more confused than ever.
But we feel we are confused on a higher level and about more important things.
-Anonymous

4

Well, Ruby doesn't try to differentiate itself in ridiculous ways just
for the sake of being different. It's not a person.
However, it will spit out a "undefined method 'elseif' for main:Object
(NoMethodError)" when you use 'elseif', so it's really not a problem
is it?

···

On Mar 7, 9:56 am, 7stud 7stud <dol...@excite.com> wrote:

What the?? I just spent two days trying to figure out why I couldn't
reproduce the example in "Ruby in 20 minutes" and get it to work. After
examining my code line for line against the example code and not being
able to detect any error, I was assembling several code examples into a
text file to post here, when I happened to notice 'elsif'. Why
didn't Ruby flag 'elseif' as an error?

Does Ruby try differentiate itself in ridiculous ways like that just for
the sake of being different? And why isn't something like that
explicitly pointed out in a beginning tutorial? So far, I have to give
Ruby two thumbs down.

C++, Java, Javascript, php, Servlets+JSP programmer

--
Posted viahttp://www.ruby-forum.com/.

--
Hans

5

Hi --

···

On 3/7/07, 7stud 7stud <dolgun@excite.com> wrote:

Does Ruby try differentiate itself in ridiculous ways like that just for
the sake of being different?

No -- literally never.

David

--
Q. What is THE Ruby book for Rails developers?
A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black\)
   (See what readers are saying! http://www.rubypal.com/r4rrevs.pdf\)
Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
A. Ruby Power and Light, LLC (http://www.rubypal.com)

6

7stud 7stud wrote:

What the?? I just spent two days trying to figure out why I couldn't
reproduce the example in "Ruby in 20 minutes" and get it to work. After
examining my code line for line against the example code and not being
able to detect any error, I was assembling several code examples into a
text file to post here, when I happened to notice 'elsif'. Why
didn't Ruby flag 'elseif' as an error?

Does Ruby try differentiate itself in ridiculous ways like that just for
the sake of being different? And why isn't something like that
explicitly pointed out in a beginning tutorial? So far, I have to give
Ruby two thumbs down.

C++, Java, Javascript, php, Servlets+JSP programmer

I have a similar language background (minus php). When I first looked at Ruby, I spent a few minutes flipping through the Pickaxe, spotted what I felt were some "Perlisms", and made a knee jerk reaction to reject the language. I've since talked to a few folks who did the same, so mine was not an isolated incident.

It was about a year later that I came back to Ruby (because of Rails) and discovered that I like the language (a lot). I'm sharing this because learning from other people's experience can be helpful. I don't know if you'll end up enjoying the language as much as I have, but it may be worthwhile to invest some more time with it before deciding. I even realized that I actually like a few of the "Perlisms" - the horror! :slight_smile:

7

Alle mercoledì 7 marzo 2007, Robert Dober ha scritto:

if true then
whatever
elseif
end

now elsif is seen as an undefined method but

Not always. In Robert's first example,

if true then
   whatever
   elseif
end

you'll get a NameError (undefined local variable or method `elseif' for
main:Object (NameError))

In the following example, instead, you get a syntax error:

if x < 0 then puts "x<0"
elseif x < 3 then puts "0<=x<3"
else puts "x>=3"
end

The error message is:

syntax error, unexpected kTHEN, expecting kEND
elseif x < 3 then puts "0<=x<3"
                 ^
Here, ruby doesn't complain because elseif doesn't exist, but because it finds
a 'then' where it shouldn't be (not following an if or elsif clause). By the
way, being a syntax error (it when the interpreter is parsing the file, not
when it executes it), this error is reported whatever the value of x is (and
even if x doesn't exist).

All these error messages aren't very easy to understand for a novice. To make
a comparison with other programming languages, I tried compiling a C program
with a similar mistake (in this case writing 'elseif' instead of 'else if').
The program was:

int main(){
int a=3;
int b=0;
if( a==4){ b=1;}
elseif(a==2){ b=2;} //should be else if
else{ b=3;}}
}

Compiling with gcc, the error message I got is:

test.c: In function 'main':
test.c:5: error: expected ';' before '{' token

As you can see, the error message doesn't speak of invalid keywords, but just
of a missing ;

Stefano

8

No of course it is not :slight_smile:
I think to understand the frustration of OP however.
He is probably coming from a completely different world and it is not
always easy to grasp new concepts.
Therefore I preferred to ignore the aggressive nature of the post ;).
He might even have a point when he says that this is maybe not really
well documented, With this I do not mean the "elseif" of course but
just the dynamic evaluation of the code.

Maybe a chapter for that kind of pitfalls could be added somewhere -
well it probably is already, maybe somebody can indicate that.

This is however not a clearcut thing as it might seem at first view.

Robert

···

On 3/7/07, Hans Sjunnesson <hans.sjunnesson@gmail.com> wrote:

On Mar 7, 9:56 am, 7stud 7stud <dol...@excite.com> wrote:
> What the?? I just spent two days trying to figure out why I couldn't
> reproduce the example in "Ruby in 20 minutes" and get it to work. After
> examining my code line for line against the example code and not being
> able to detect any error, I was assembling several code examples into a
> text file to post here, when I happened to notice 'elsif'. Why
> didn't Ruby flag 'elseif' as an error?
>
> Does Ruby try differentiate itself in ridiculous ways like that just for
> the sake of being different? And why isn't something like that
> explicitly pointed out in a beginning tutorial? So far, I have to give
> Ruby two thumbs down.
>
> C++, Java, Javascript, php, Servlets+JSP programmer
>
> --
> Posted viahttp://www.ruby-forum.com/.

Well, Ruby doesn't try to differentiate itself in ridiculous ways just
for the sake of being different. It's not a person.
However, it will spit out a "undefined method 'elseif' for main:Object
(NoMethodError)" when you use 'elseif', so it's really not a problem
is it?

--
Hans

--
We have not succeeded in answering all of our questions.
In fact, in some ways, we are more confused than ever.
But we feel we are confused on a higher level and about more important things.
-Anonymous

9

David A. Black wrote:

Hi --

Does Ruby try differentiate itself in ridiculous ways like that just for
the sake of being different?

No -- literally never.

David

Yeah. Like the use of "throw" and "catch"; ".inject"; "yieieild" that's
not really the yield of coroutines, but just a way to call the unnamed
closure (or the unnamed unnamed function) that was passed to the method
as the last parameter; the fact that "and" and "or" have the same
precedence, while && has bigger precedence than ||, etc. etc. etc.

The fact that I'm supposed to write

puts 1 + 2 +
  3

or

puts 1 + 2 \
  + 3

(Visual Basic anyone?) it fairly ... wuby as well.

···

On 3/7/07, 7stud 7stud <dolgun@excite.com> wrote:

--
Posted via http://www.ruby-forum.com/\.

10

Brian Adkins wrote:

7stud 7stud wrote:

explicitly pointed out in a beginning tutorial? So far, I have to give
Ruby two thumbs down.

C++, Java, Javascript, php, Servlets+JSP programmer

I have a similar language background (minus php). When I first looked at
Ruby, I spent a few minutes flipping through the Pickaxe, spotted what I
felt were some "Perlisms", and made a knee jerk reaction to reject the
language. I've since talked to a few folks who did the same, so mine was
not an isolated incident.

It was about a year later that I came back to Ruby (because of Rails)
and discovered that I like the language (a lot). I'm sharing this
because learning from other people's experience can be helpful. I don't
know if you'll end up enjoying the language as much as I have, but it
may be worthwhile to invest some more time with it before deciding. I
even realized that I actually like a few of the "Perlisms" - the horror!
:slight_smile:

Don't worry. They'll go away. The Wuby moto is break what works, rename
what's commonly known and add gotchas for fun.

Jenda

···

--
Posted via http://www.ruby-forum.com/\.

11

"Chad Perrin" <perrin@apotheon.com> wrote in message
news:20070307085933.GB25634@apotheon.com...

"Different" would be more like the way bash does it: "elif"

Different?

Algol 68 spelled it that way in 1967, a spelling that the Bourne Shell
adopted in Unix in 1977.

12

Maybe a chapter for that kind of pitfalls could be added somewhere -
well it probably is already, maybe somebody can indicate that.

Perhaps at the "Ruby from other languages" page :
http://www.ruby-lang.org/en/documentation/ruby-from-other-languages/

I find this page very helpful.

Regards,

Chris

···

--
Posted via http://www.ruby-forum.com/\.

13

<snip>

Good points Stefano, conclusion *always* use "then" :slight_smile:

···

On 3/7/07, Stefano Crocco <stefano.crocco@alice.it> wrote:
--
We have not succeeded in answering all of our questions.
In fact, in some ways, we are more confused than ever.
But we feel we are confused on a higher level and about more important things.
-Anonymous

14

Don't worry. They'll go away. The Wuby moto is break what works, rename
what's commonly known and add gotchas for fun.

I've seen it mentioned a couple of times--what the heck is wuby?

···

--
Posted via http://www.ruby-forum.com/\.

15

Not to mention that Ruby builds on Perl, which uses elsif.

Mike

···

On 08/03/07 Andrew Koenig said:

Different?

Algol 68 spelled it that way in 1967, a spelling that the Bourne Shell
adopted in Unix in 1977.

--
Michael P. Soulier <msoulier@digitaltorque.ca>
"Any intelligent fool can make things bigger and more complex... It
takes a touch of genius - and a lot of courage to move in the opposite
direction." --Albert Einstein

16

Remember in those days, heck even in the 80's languages and tools (programs) used the shortest names possible because computing power and memory were at a premium so even saving one character made a difference. Thus we get all these sick little names for Unix tools, love them or hate them.

···

On Mar 8, 2007, at 2:15 AM, Andrew Koenig wrote:

"Chad Perrin" <perrin@apotheon.com> wrote in message
news:20070307085933.GB25634@apotheon.com...

"Different" would be more like the way bash does it: "elif"

Different?

Algol 68 spelled it that way in 1967, a spelling that the Bourne Shell
adopted in Unix in 1977.

17

I was being slightly facetious. I really don't see anything
particularly wrong with any of these variations that have been discussed
here.

···

On Thu, Mar 08, 2007 at 02:15:07AM +0900, Andrew Koenig wrote:

"Chad Perrin" <perrin@apotheon.com> wrote in message
news:20070307085933.GB25634@apotheon.com...

> "Different" would be more like the way bash does it: "elif"

Different?

Algol 68 spelled it that way in 1967, a spelling that the Bourne Shell
adopted in Unix in 1977.

--
CCD CopyWrite Chad Perrin [ http://ccd.apotheon.org ]
print substr("Just another Perl hacker", 0, -2);

18

Chris Lowis wrote:

Maybe a chapter for that kind of pitfalls could be added somewhere -
well it probably is already, maybe somebody can indicate that.

Perhaps at the "Ruby from other languages" page :
Ruby From Other Languages

I find this page very helpful.

Regards,

Chris

First, I'd like to say that the web site is really beautiful and eye
catching. There are some minor problems, for instance, the code
examples are in a small area width wise, so there is a horizontal scroll
bar that you need to scroll to the right to see the latter portion of a
line of code. However, the area with the code is very tall(more than
one screen), and it is very inconvenient to page all the way down to the
bottom in order to scroll to the right, and then go all the way back up
in order to read the code. Also, no matter how wide I make my browser
window(Safari 2.0.4), the area with the code does not expand
horizontally. It should expand horizontally as the browser window gets
wider, and the horizontal scroll bars should disappear.

If I run the following code, I don't get any errors:

class MegaGreeter
        attr_accessor :names

        #constructor
        def initialize(names = "world")
                @names = names
        end

        #functions:
        def say_hi
                if @names.nil?
                        puts "..."
                elseif @names.respond_to?("each")
                        @names.each do |name|
                                puts "Hello #{name}!"
                        end
                else
                        puts "Hello #{@names}!"
                end
        end
end
if __FILE__ == $0
        mg = MegaGreeter.new(["Sally", "Jane", "Bob"])
        mg.say_hi
end

···

--
Posted via http://www.ruby-forum.com/\.

19

Jenda, at least this version of Jenda since others seem to recognise
said person as a positive influence in the Perl world at one point, is
a troll.

There's absolutely nothing of value in what Jenda says at this point.

-austin

···

On 3/7/07, 7stud 7stud <dolgun@excite.com> wrote:

> Don't worry. They'll go away. The Wuby moto is break what works, rename
> what's commonly known and add gotchas for fun.
I've seen it mentioned a couple of times--what the heck is wuby?

--
Austin Ziegler * halostatue@gmail.com * http://www.halostatue.ca/
               * austin@halostatue.ca * You are in a maze of twisty little passages, all alike. // halo • statue
               * austin@zieglers.ca

20

It's a sarcastic, trollish way of saying "Ruby" if you're trying to
convey a sense that it is childish. The only person I've ever seen use
that spelling is "Jenda", and it's already getting old. If you're going
to choose to avoid Ruby, please don't do so because of what a troll
said.

···

On Thu, Mar 08, 2007 at 03:50:17AM +0900, 7stud 7stud wrote:

> Don't worry. They'll go away. The Wuby moto is break what works, rename
> what's commonly known and add gotchas for fun.

I've seen it mentioned a couple of times--what the heck is wuby?

--
CCD CopyWrite Chad Perrin [ http://ccd.apotheon.org ]
"There comes a time in the history of any project when it becomes necessary
to shoot the engineers and begin production." - MacUser, November 1990