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I'd like to turn String into lists. For example, http => (h t t p).
I try:
(defun string-to-list (s)
(assert (stringp s) (s) "~s :questa non e una stringa")
(coerce s 'list))
but if I do
(string-to-list "http")
results:
(#\h #\t #\t #\p).
Can I remove #\ ? thanks in advance :)
288
Method#1: Using split() method If a delimiter is not specified or is None, a different splitting algorithm is applied: runs of consecutive whitespace are regarded as a single separator, and the result will contain no empty strings at the start or end if the string has leading or trailing whitespace.
The most straightforward way is to type cast the string into a list. Tyepcasting means to directly convert from one data type to another – in this case from the string data type to the list data type. You do this by using the built-in list() function and passing the given string as the argument to the function.
To create a list of strings, first use square brackets [ and ] to create a list. Then place the list items inside the brackets separated by commas. Remember that strings must be surrounded by quotes. Also remember to use = to store the list in a variable.
The split() method splits a string into a list. You can specify the separator, default separator is any whitespace. Note: When maxsplit is specified, the list will contain the specified number of elements plus one.
Why would you do that? What you ask is to split a string (a one-dimensional array of characters) into a list of symbols. Do you really want that?
#\h is a character object printed.
You can print them differently:
CL-USER 8 > (princ #\h)
h
CL-USER 9 > (prin1 #\h)
#\h
Let's print the list using PRINC:
CL-USER 10 > (map nil #'princ (coerce "Hello!" 'list))
Hello!
Btw., since strings, vectors and lists are sequences, you can MAP directly over the string...
CL-USER 11 > (map nil #'princ "Hello!")
Hello!
You can turn a string into a symbol with intern. You can turn a character into a string with string. Interning a lower-case string might cause it to be printed as |h| instead of h, so you'll want to string-upcase it. Putting all that together gives:
(loop for c in (coerce "http" 'list)
collecting (intern (string-upcase (string c))))
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