Hi everybody,

I am beginer in Common Lisp. I am trying to create a code that asks the user if he wants to run firefox browser with y/n answer.

I have this code

If I run this code I receive this error message: *** - EVAL: too few parameters for special operator IF: (IF (= ANSWER "y"))

How to resolve this issue? Thank you for your advice

Auto-indent the code in your editor (if your editor doesn't support that, find one that does). You will get this:
Which is obviously wrong, the culprit is an extra close paren on the first line (I highlighted it). Also, the the general structure of an if form looks like this:

There are no keywords apart from the "if" itself, and you don't need to repeat/reverse the test.

See Common Lisp the Language, 2nd Edition - 7.6. Conditionals

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With a new language seemingly appearing every other month, lisp still has (new) adherents ????.
Memories from the 70s struggle to emerge...

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Yes, syg, people still enjoy working with "Lots of Irritating Silly Parentheses!"

Use 'string=' rather than '=' for the comparison, or you'll likely get a "Not a Number" error. Also, read will likely uppercase the input unless you take steps to prevent it (google readtable-case), so you need to compare with "Y" not "y".

And yeah, an editor that does parenthesis matching/highlighting is a must have when you're doing lisp, otherwise you'll go insane.

The new languages, imho, haven't improved computer science -- mostly just vanity (see I made a programming language, too), or economic power trips (we'll make our own language for our platform, and when developers use our language, it will advance our platform) This doesn't advance computer science, but rather obfuscates it by making it less homogenous for no reason other than vanity and greed.

Way to see through the crud, Petr Strajt: welcome to secret alien technology!

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Yabbut - is it going to get the OP a job ?.

When I graduated, I had to move state to get a job because I hadn't taken the optional COBOL units (it was a while ago). Nobody gave a damn about the nicities of compsci - they wanted people who could help the business run the business that made them money.
Dunno what the job market is these days tho'.

is this then or than ?

Yes, there are common lisp jobs -- often one must search for functional programming... and common lisp has bindings to so many other languages, that you can take, for example, a job building qt widgets, and use commonqt/smoke to create the widgets... good employers don't care how you do it as long as you do it. The job title might not say lisp or functional programming, but instead say qt. There's heaps of medical statistics jobs these days, mostly using R. But common lisp has you covered with bindings to R as well.

Of course, you have to want a job in the first place...

and(
((an))()(((interesting)))(question)
if(
so((do)(not)(((expect (to be))))(life(the of(the(party))


No. I have no idea if the parentheses match.

Neither. See the explanation by ntubski in #2.

I remember seeing a visual interface to the LISP programming language which simply presented the inherent list/node structure of a program in a graphical way. You could open the program with it, change it visually, and then save it. IIRC, it also had the ability to recognize syntax errors. Unfortunately, I no longer remember what it was called. (AutoCAD has something called "Visual LISP" which is not the same thing.)

One thing's quite sure, though: "LISP will never die." Possibly the very-earliest language ever invented.

i havent logged in, in so long and finally i did and noticed a LISP! question , and on a not too ancient thread either, well if incase someone sees this i'll leave my own 2 cents here

or you can just use string-equal since that is case insensitive that way you can accept both cases of y or Y without resorting to a cond or a nested if, for more concise code,

then use to run firefox with an optional specific url in mind.

TIP: also dont get used to setq just use setf when mutating bindings

you can also write your code by defining a function instead and just using let for variable declaration, for ex:

P.S. I'd also like to suggest for beginners interested in learning Lisp, to try to use Racket first instead of Common Lisp, its just easier to get set up in the beginning, super easy brain dead simple install, and Racket comes with an IDE thats easy to use right at the start so you dont get overwhelmed and learn without much distraction unlike starting with Common Lisp theres plenty much to learn and configure before you get going which detracts from the learning, then after you can switch to Common Lisp, when you get your bearings, if you still want to that is, as Racket is plenty capable as a Lisp(but as a Scheme derivative Lisp dialect with batteries included), but hey Common Lisp Rocks too, you cant beat SLIME on EMACS

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0++, use [code] rather than [quote] tags.