> Lisp is not typically a low-level programming language,
For most practical reasons is pretty low level. You don't really write in a language you write in AST directly, which while powerful IMO is not very high level.
One writes in a hierarchical data structure: s-expressions. Since Lisp has built-in macro expressions, on top of s-expressions, one can represent code independent from 'ASTs' and make it executable:
For example the LOOP macro introduces a non-prefix syntax:
(loop
for i below 100
for j = (random 100)
sum j into s
while (< s 1000)
finally (return i))
This is actually pretty powerful and high-level (the user being able to extend or change the syntax in complex ways in portions of a program). The LOOP implementation as a macro is actually an integrated sublanguage and the user can add arbitrary (and even extensible) complex macros like that...
Generally Lisp is low to mid level as a programming language, with a bunch of features which can be considered high-level: extensive macro system, Common Lisp Object System, extensive error handling, ...
Something like a cons cell (the building block for lists) is basically a two-element vector. Lists were made by chaining them together via a CONS operator, which creates such a two-element vector.
Such a linked list data structure is pretty low-level and the typical mark&sweep GC of the early days is also relatively basic.
There is not much magic to it.
Many other programming languages have much more complex basic data structures (see object-oriented programming in Java with classes and instances, inheritance, interfaces, namespaces, ...). Compared to that the basic linked list in Lisp is primitive.
> I believe that no programming language with automatic memory management can be considered "low-level".
See the standards for Scheme or Common Lisp. There is not a word about automatic memory management in the specifications. Automatic memory management is a feature of an implementation, just like foreign function interfaces. Most implementations have a kind of garbage collector. But most implementations also have manual memory management.
Sounds like lisp is doing the low level stuff for you, so really like a mid/high level language. Most languages have statements that correspond to a single cpu instruction. And it sounds like this cons cell is in fact an abstraction away from bytes and memory. Which is more of an abstraction than, say, a byte string.
For example the LOOP macro introduces a non-prefix syntax:
This is actually pretty powerful and high-level (the user being able to extend or change the syntax in complex ways in portions of a program). The LOOP implementation as a macro is actually an integrated sublanguage and the user can add arbitrary (and even extensible) complex macros like that...Generally Lisp is low to mid level as a programming language, with a bunch of features which can be considered high-level: extensive macro system, Common Lisp Object System, extensive error handling, ...