LISP

[440bx]

However I'm not convinced that problems which require multiple /infinite/ tapes can *realistically* be mapped onto a single /infinite/ tape... at least without requiring infinite time for the housekeeping in addition to the finite time required to execute the algorithm.

Leaving any housekeeping aside that may be necessary to carry out the mapping for real, as counter intuitive as it sounds, it is possible to map an infinite number of infinities onto a single infinity.

For instance, take the infinity of natural numbers 1, 2, 3, ....

That infinity contains an infinite number of infinities, for instance, the infinity 2, 4, 6, 8... (enumerate by 2),  and 3, 6, 9, 12, ... (enumerate by 3) and so on... there is an infinite number of enumerations in the natural numbers infinity BUT...

The infinity of _irrational_ numbers is "larger" than the infinity of natural numbers because it is not possible to establish a 1 to 1 relationship between all irrational numbers and natural numbers (there will always be unmapped irrational numbers)

Infinities are real mind benders...

[MarkMLl]

Leaving any housekeeping aside that may be necessary to carry out the mapping for real

But in practice, and I emphasise that Pascal was intended to be a usable language, is that really realistic?

That's one of the problems with APL: in practice, algorithms were developed that had good O(n) metrics relative to time but no consideration was given to O(n) relative to space (i.e. the overhead required to swap between primary and secondary or even tertiary storage).

MarkMLl

[440bx]

Leaving any housekeeping aside that may be necessary to carry out the mapping for real

But in practice, and I emphasise that Pascal was intended to be a usable language, is that really realistic?

I agree that it is unlikely to be realistic which is why I stated what followed required leaving aside housekeeping considerations necessary in real cases.

[Weiss]

Hope the book is a good one, not just "scratching" on the subject.

ANSI Common Lisp. I left it home, only went through very first steps. Good or not, it was only book available in public library, I will have to make it work, when I get back from the ship.

 

As a non-LISP programmer I liked this https://www.youtube.com/watch?v=-J_xL4IGhJA

good lecture, thank you for sharing. Speaker is truly driven enthusiast, if I wasn't a programmer already would probably want to become one.

[d2010]

You can develop , many library , of LISP sources.
In this mode, You increase of size of Lisp-program~s.
 

I wonder how much value in learning LISP these days? The language has rather unusual syntax. Is it going to get better as I keep learning it? ?