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Lambda Calculus and Lisp, part 1

by baruchel on 2/23/25, 9:29 AM with 17 comments

• by codr7 on 2/23/25, 1:24 PM

  I certainly appreciate the theoretical beauty of lambda calculus, but I do wonder what the point is from a modern implementation perspective.

  Most hobby Lisps I run into seem to be more of a lambda calculus rite of passage than aiming for practical use.

  I've implemented several Lisp interpreters myself in different languages, very much focused on practical use, and they don't look anything like this.

  https://github.com/codr7/eli

• by Traubenfuchs on 2/23/25, 10:46 AM

  I remember having memorised lambda calculus solving techniques to pass my CS exams on paper where the 2-forearm wide lines had to be wrapped multiple times.

  And now, just like a decade ago, my eyes glaze over when I read about this.

  I can easily reason about functions that return functions that return functions but this just completely goes over my head.

• by tosh on 2/23/25, 12:45 PM

  The Byte magazine referenced in the article:

  Byte Magazine Volume 04 Number 08 - LISP

  https://archive.org/details/byte-magazine-1979-08

• by lkuty on 2/24/25, 7:44 AM

  Simple typo. "(That is, an expression (λx.M) combining with an expression N returns (M) where all instances of x inside of M are replaced by x.)" Are replaced by N.