LispForum

You probably want something like this.

What operations are you looking for? How many dimensions? What does this library integrate with? On one hand, there are simple roll-your-own solutions, such as the complex coordinate system in SICP. https://mitpress.mit.edu/sites/default/files/sicp/full-text/book/book-Z-H-17.html On the other hand, ...

Construct a new list. Include the original head, new middle, and original tail.

There are ways to destructively modify the middle value in the original list (setf ...), but I think the new list is what your instructor is looking for.
If done right, the amount of code is about the same either way.

There are a few ways to do this.

I would guess that you are supposed to use recursion for complex forms.

In other words, have the product function call product on smaller pieces of the input.

Things to look at / fix: called REMOVE instead of MY-REMOVE hard-coded #\R instead of using the passed parameter pass a character to remove instead of a quoted symbol (#\r vs 'r) run (string 'nose) and look at the capitalization of the result P.S. The forum strips backslashes. Double-backslash is co...

It sounds to me like you are asking how to do type-based function dispatch in Lisp. My recommendation is simple. If your goal is to write applications, then start with CLOS (or the native object system of your Scheme) and only switch if you hit some limit, at which point you will have identified spe...

In LISP, afaik, eval uses null lexical environment and current dynamic environment Agreed. so a function argument (parameters are lexical) cannot be re-evaluated inside a function. I think I follow your question. Common Lisp evaluates function arguments in the calling context, before the function i...

I had to read the full "Yacas evaluation scheme" on the linked page to understand the quoted statement. Back in the "good old days" (so I'm told), things like scoping rules were not taken for granted, and there were many ideas for how a variable name is mapped to a memory locatio...

I'm no AutoLisp expert, but I believe that (assoc 0 xcx) will return "TEXT", and (assoc 1 xcx) will return the desired text value. Use these in the strcat function as desired. http://www.jefferypsanders.com/autolispexp_enti.html#Text https://www.autodesk.com/techpubs/autocad/acad2000/dxf/t...

There are cases where the consing is quite cheap. For example, a single pick, or if the pick index is always small. Don't know enough about the OP's use case to say one way or the other. Maybe he should copy the whole list into an array. Then pick becomes aref or svref. ;) Much better amortized time...