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The Land of Lisp

landoflisp.com

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Re: The Land of Lisp

#82

Post by hellofunk »

lispm wrote: post #78
hellofunk wrote: post #63

When I discovered lisp several years ago, it was indeed the textbook moment of enlightenment that you've heard about. This book was a part of that introduction for me (along with Practical Common Lisp). After working in C-like languages, I had no idea that programming could work this way as in lisp, the idea of code and data being inseparable, I even had dreams at night about run-time data structures getting expresse…

Common Lisp: (defmethod collide ((object1 space-ship) (object2 rocket)) "Inline documentation for this method..." (the debris (create-debris-from space-ship)) SPACE-SHIP and ROCKET are types and classes. DEBRIS would also be a type and a class. Use DEFTYPE, DEFCLASS, DEFSTRUCT, ... to define new types. Use CHECK-TYPE and ASSERT to have runtime checks, integrated with the condition system.

Well I can do runtime checks just as easily in Clojure, but I'm really talking about compile time checks.

Re: The Land of Lisp

#83

Post by davexunit »

etatoby wrote: post #42

I've learned LISP and Scheme, gained some useful insights, used them on a few random projects, and then dropped them. I recommend learning them, but then switching to something like Reason / OCaml / F# / Haskell.

counter anecdote: I use and contribute to a number of Scheme programs that I use daily and would never want to switch to any static language. Life at the REPL is too good.

Re: The Land of Lisp

#87

Post by lispm »

hellofunk wrote: post #82
lispm wrote: post #78

Earlier quoted context omitted.

Common Lisp: (defmethod collide ((object1 space-ship) (object2 rocket)) "Inline documentation for this method..." (the debris (create-debris-from space-ship)) SPACE-SHIP and ROCKET are types and classes. DEBRIS would also be a type and a class. Use DEFTYPE, DEFCLASS, DEFSTRUCT, ... to define new types. Use CHECK-TYPE and ASSERT to have runtime checks, integrated with the condition system.

Well I can do runtime checks just as easily in Clojure, but I'm really talking about compile time checks.

You actually said:

> Without type annotations and checked structured data for everything, it can also be hard to remember what a function does, or what its variables represent, when you read the code later.

I showed you how to annotate types in Common Lisp.

You also said:

> The other feature that occurs more often is in-line documentation.

Which exists in Lisp since 80s or earlier.

> but I'm really talking about compile time checks.

  (declaim (ftype (function (integer string) cons)
		  foo))
  (defun foo (a b)
    (list a b))

  (defun bar (a) (foo "baz" a))
Running the SBCL compiler:

  ; file: /private/tmp/test.lisp
  ; in: DEFUN BAR
  ;     (FOO "baz" A)
  ; 
  ; note: deleting unreachable code
  ; 
  ; caught WARNING:
  ;   Constant "baz" conflicts with its asserted type INTEGER.
  ;   See also:
  ;     The SBCL Manual, Node "Handling of Types"
At least some type checks are done at compile time...

Re: The Land of Lisp

#89

Post by flavio81 »

hellofunk wrote: post #82
lispm wrote: post #78

Earlier quoted context omitted.

Common Lisp: (defmethod collide ((object1 space-ship) (object2 rocket)) "Inline documentation for this method..." (the debris (create-debris-from space-ship)) SPACE-SHIP and ROCKET are types and classes. DEBRIS would also be a type and a class. Use DEFTYPE, DEFCLASS, DEFSTRUCT, ... to define new types. Use CHECK-TYPE and ASSERT to have runtime checks, integrated with the condition system.

Well I can do runtime checks just as easily in Clojure, but I'm really talking about compile time checks.

>Well I can do runtime checks just as easily in Clojure, but I'm really talking about compile time checks.

Take a look at this: http://ahungry.com/blog/2015-07-10-Type-Safety-and-Lack-Ther...

It shows you a 9-lines macro for CL, that allows you to declare types in a way resembling Haskell, and having the compiler do the static checks.

Very nice.

Another example is here: https://news.ycombinator.com/item?id=8598149

Re: The Land of Lisp

#90

Post by zaph0d »

flavio81 wrote: post #22

This book is destined to be a classic programming book, just as "The C programming language", "The Little Schemer" or "Operating systems: Design and implementation". I would really like to meet Conrad Barski and give him a great hug. And invite him a good beer. Be sure to read the comic that is on the bottom of the page!! Now, to be honest, a quicker or more practical introduction to Lisp would be the "Practical Comm…

I started my career hacking Common Lisp (Allegro CL), these days I do Clojure, among other things.

That comic by Dr. Barski tears me up every time! Just to test, I went and read the comic again and I cried, again!

I have met Dr. Barski personally at a Clojure conference many years ago and I still remember him as an extremely kind and knowledgeable person.

Thank you for the Land of Lisp, Dr. Barski! Some day, we will be able to assemble our guilds and beat the Insectoids for good. Until then,long live language du jour!

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