In most Lisp languages, you only can "append" to a list, never "prepend".
Python, e.g., has such structures: https://www.geeksforgeeks.org/deque-in-python/ The "*d*ouble *e*nded *queue*". Appending, prepending, Python simply lets you do, what you want! ;-) Mighty, mighty stuff, highly efficient! Have fun! Am Montag, 27. April 2020 schrieb Wilhelm Fitzpatrick <raf...@well.com>: > I've been digging down to really understand the symbol implementation in Picolisp, since symbols are used for so many purposes within the language. > > One surprising thing I learned last night is that (get ...) has a side effect! It moves the key that was accessed to the head of the symbol "tail". I assume this is a performance optimization to cause recently accessed properties to "bubble up" to the front of the list in case they are re-accessed soon. > > A few questions: > > 1. I understand why (cdr) doesn't function on a symbol (semantically it's not a pair) but I'm curious why (car) is allowed to work (returning the VAL)? > > 2. Is there anyway within the REPL to inspect the tail structure of the symbol directly? This is mostly from curiosity. > > 3. Again from curiosity, I'm wondering why the bytes of the name are seemingly stored "backwards"? I'm assuming this also provides some performance optimization. > > -wilhelm > > > -- > UNSUBSCRIBE: mailto:picolisp@software-lab.de?subject=Unsubscribe >
