How do I get the set of all letters in Java/Clojur

Question

In Python, I can do this:

>>> import string
>>> string.letters
'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'

Is there any way to do something similar in Clojure (apart from copying and pasting the above characters somewhere)? I looked through both the Clojure standard library and the java standard library and couldn't find it.

Answer 1

A properly non-ASCII-centric implementation:

private static String allLetters(String charsetName)
{
    CharsetEncoder ce = Charset.forName(charsetName).newEncoder();
    StringBuilder result = new StringBuilder();
    for(char c=0; c<Character.MAX_VALUE; c++)
    {
        if(ce.canEncode(c) && Character.isLetter(c))
        {
            result.append(c);
        }
    }
    return result.toString();
}

Call this with "US-ASCII" and you'll get the desired result (except that uppercase letters come first). You could call it with Charset.defaultCharset(), but I suspect that you'd get far more than the ASCII letters on most systems, even in the USA.

Caveat: only considers the basic multilingual plane. Wouldn't be too hard to extend to the supplementary planes, but it would take a lot longer, and the utility is questionable.

Answer 2

If you just want Ascii chars,

(map char (concat (range 65 91) (range 97 123)))

will yield,

(\A \B \C \D \E \F \G \H \I \J \K \L \M \N \O \P \Q \R \S \T \U \V \W \X \Y \Z 
 \a \b \c \d \e \f \g \h \i \j \k \l \m \n \o \p \q \r \s \t \u \v \w \x \y \z)