Idiomatically determine all the characters that can be used for symbols: Difference between revisions

[http://docs.racket-lang.org/guide/symbols.html Symbols in the Racket Guide] states that:

<blockquote>Any string (i.e., any character sequence) can be supplied to <code>string->symbol</code> to obtain

the corresponding symbol.</blockquote>

[http://docs.racket-lang.org/reference/reader.html#%28part._parse-symbol%29 Reading Symbols] defines

what symbols can be "read" without needing quoting.

The docuementation for

[http://docs.racket-lang.org/reference/characters.html#%28def._%28%28quote._~23~25kernel%29._integer-~3echar%29%29 <code>integer->char</code>]

says that a character must lie in the ranges: 0 to 55295, and 57344 to 1114111.

That's too much to be printing out here... call <code>(main)</code> yourself, at home.

<lang racket>#lang racket

;; Symbols that don't need to be specially quoted:

(printf "~s~%" '(a a-z 3rd ...---... .hidden-files-look-like-this))

;; Symbols that do need to be specially quoted:

(define bar-sym-list

`(|3|

|i have a space|

|i've got a quote in me|

|i'm not a "dot on my own", but my neighbour is!|

|.|

,(string->symbol "\u03bb")

,(string->symbol "my characters aren't even mapped in unicode \U10e443")))

(printf "~s~%" bar-sym-list)

(printf "~a~%" bar-sym-list)

(define (main)

(for

((c (sequence-map

integer->char

(in-sequences (in-range 0 (add1 55295))

(in-range 57344 (add1 1114111)))))

(i (in-naturals 1)))

(when (zero? (modulo i 80)) (newline))

(display (list->string (list c)))))

<pre>(a a-z 3rd ...---... .hidden-files-look-like-this)

(|3| |i have a space| |i've got a quote in me| |i'm not a "dot on my own", but my neighbour is!| |.| λ |my characters aren't even mapped in unicode 􎑃|)

(3 i have a space i've got a quote in me i'm not a "dot on my own", but my neighbour is! . λ my characters aren't even mapped in unicode 􎑃)</pre>