Can anyone explain how does listp in Lisp work ?
CL-USER 2 : 1 > (if (listp 1) (+ 1 2) (+ 3 4))
7
What's this about ?
So you have an "if" , a "listp 1" , a (+ 1 2) and a (+ 3 4) and the output result is 7. How does this work ?
Search found 14 matches
- Wed Dec 21, 2016 1:43 pm
- Forum: The Lounge
- Topic: How to start learning Lisp
- Replies: 3
- Views: 27992
How to start learning Lisp
Ok ... how do I start learning Lisp ??
- Wed Dec 21, 2016 1:40 pm
- Forum: The Lounge
- Topic: Average Lisp age?
- Replies: 36
- Views: 498772
Re: Average Lisp age?
Im 32 ... just started learning Lisp. Reading Paul Graham's Ansi Common Lisp ... but is pretty tough
- Wed Dec 21, 2016 5:40 am
- Forum: The Lounge
- Topic: Learning Lisp
- Replies: 1
- Views: 20468
Learning Lisp
Ok, I am a newbie here. From Singapore ... studied electrical engineering(Bachelors) at Northwestern University for around 7 years but dropped out of school a few times due to depression, suicidal ideation and lack of motivation and got my student visa denied the last time I reapplied back about 5 y...
- Mon Jul 25, 2016 9:49 pm
- Forum: Common Lisp
- Topic: exercism fetch TRACK_ID Error Message
- Replies: 3
- Views: 10036
Re: exercism fetch TRACK_ID Error Message
I have absolutely no idea what that means ... its so frustrating. Can i pay someone to go through Paul Graham's Ansi Common Lisp with me in person ?
- Mon Jul 25, 2016 2:42 pm
- Forum: Common Lisp
- Topic: exercism fetch TRACK_ID Error Message
- Replies: 3
- Views: 10036
exercism fetch TRACK_ID Error Message
From Point number 4 of "Fetch The First Exercise" from http://exercism.io/how-it-works, I got this error ------- CL-USER 4 : 3 > exercism fetch TRACK_ID Error: Undefined operator EXERCISM in form (EXERCISM FETCH TRACK_ID). 1 (continue) Try invoking EXERCISM again. 2 Return some values from...
- Tue Aug 25, 2015 12:56 am
- Forum: Common Lisp
- Topic: Building a Finance Program In Lisp
- Replies: 0
- Views: 9124
Building a Finance Program In Lisp
Hi, So I want to use Lisp to build a personal finance program on a website. This is how it should look like and work : MediciNotes.com User Name: User Log In: Time and Date today: Expenses and Source: Earnings and Source: Net earnings for the month: Net earnings for the year: $$$$$ An animated video...
- Fri Jul 03, 2015 9:09 am
- Forum: Common Lisp
- Topic: Paul Graham's Hackers And Painters
- Replies: 1
- Views: 7965
Paul Graham's Hackers And Painters
In Paul Graham's book "Hackers and Painters, on page 169, he mentioned that : Eric Raymond has written an essay called "How to Become a Hacker," and in it, among other things, he tells would-be hackers what languages they should learn. He suggests starting with Python and Java , becau...
- Fri Jul 03, 2015 8:36 am
- Forum: Common Lisp
- Topic: Simple Number Guessing Game
- Replies: 0
- Views: 9241
Simple Number Guessing Game
This is a simple number guessing game written in Lisp : (defparameter *small* 1) (defparameter *big* 100) (defun guess-my-number () (ash (+ *small* *big*) -1)) (defun smaller () (setf *big* (1- (guess-my-number))) (guess-my-number)) (defun bigger () (setf *small* (1+ (guess-my-number))) (guess-my-nu...
- Fri Jul 03, 2015 8:03 am
- Forum: Common Lisp
- Topic: Creating a hash of hashes
- Replies: 6
- Views: 17518
Re: Creating a hash of hashes
Strangely enough, when I ran all of the code examples given in this topic, none of them worked at all. I have copy and pasted my code below ... if anyone can give any enlightenment on this issue, that would be great ! CL-USER 1 > (create-hash master-hash :size 10) Error: Undefined operator CREATE-HA...