LispForum

What please is a polyline? There is no built-in concept of a polyline in Common Lisp. I do not think that anybody can answer your question as long as you do not explain what you are talking about. I' sorry, but 'Im no a mind reader and my glass ball is on holidays.

- edgar

I had worked with several other programming languages before and started learning Lisp with David Tourtzky's Gentle Introduction , but found it "too basic" (what is not true, but I didn't realized it at that time). Then I read Peter Seibel's Practical Common Lisp , David Lamkin's Sucessful...

The difference is subtle and not visible on the first view, but APPEND makes copies of all of its arguments, except of its last argument. For the last argument the elements are copied by the recursive function from the y-list. The result is a list that is completely independent from the structure of...

Is it possible to establish a condition handler at the REPL in such a way that it can handle conditions that occur at the REPL? Only if the condition handler is established before the REPL is started. For example, some Common Lisp implementations provide command-line arguments or implementation-spe...

Setting the value of a sub-hashtable: (setf (gethash sub-key (gethash master-key master-table)) sub-value) Using multi-dimensional hashtables leads to code that nobody understands. How can I create a string from a symbol (how can I get its "name"...) ? By using SYMBOL-NAME ... - edgar

See PROGN and use it like this:

HYPERSPEC is (sorry) not something I would like to call "readable"... The Hyperspec is formatted to be read with Emacs-w3m , not with Firefox. The format controls in the Hyperspec are in Chapter 22.3: Formatted Output and sub-chapters, linked near the bottom of that page. Common Lisp the ...

What is the advantage for the "." in between the offsets? (1 . 2) needs only half the memory of (1 2) (cons 1 2) => (1 . 2) (car '(1 . 2)) => 1 (cdr '(1 . 2)) => 2 +-----+-----+ | 1 | 2 | +-----+-----+ (1 . 2) is one cons cell in memory = two memory locations (list 1 2) == (cons 1 (cons 2...

...and another one: Look at Common Lisp's PARSE-INTEGER function if you want to transform the numerical strings into integer numbers.

- edgar

Helper function that returns a substring from START to STOP with leading and trailing whitespace removed, or NIL if no such token is specified in the line, either because the substring between START and STOP contains only whitespace, or the START of the substring is beyond the END of the line: (defu...