[Chicken-janitors] #183: symbols starting with # do not have read-write invariance

[Chicken Trac]

#183: symbols starting with # do not have read-write invariance
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 Reporter:  zbigniew        |       Owner:       
     Type:  defect          |      Status:  new  
 Priority:  minor           |   Milestone:  4.4.0
Component:  core libraries  |     Version:  4.3.x
 Keywords:                  |  
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 I noticed this because if I have a string "#hostinfo#" and do
 string->symbol on it and write it to a file, (read) on this file causes a
 syntax error.

 I am not sure, but at first glance you might fix this by changing
 (not (##core#inline "C_substring_compare" "#!" str 0 0 2))
 to
 (not (##core#inline "C_substring_compare" "#" str 0 0 1))
 or a more efficient equivalent in sym-is-readable? in library.scm.  As far
 as I know, anything starting with # is sharp-syntax and is unlikely to be
 read as a symbol.  Yes?

 Examples:
 {{{
 #;> (with-input-from-string (with-output-to-string (lambda () (write
 (string->symbol "#x")))) read)
 Error: illegal number syntax: ""

 #;> (with-input-from-string (with-output-to-string (lambda () (write
 (string->symbol "#hostinfo")))) read)
 Error: invalid sharp-sign read syntax: #\h

 #;> (symbol? (with-input-from-string (with-output-to-string (lambda ()
 (write (string->symbol "#t")))) read))
 #f

 #;> (char? (with-input-from-string (with-output-to-string (lambda ()
 (write (string->symbol "#\\x")))) read))
 #t
 }}}

-- 
Ticket URL: <http://www.irp.oist.jp/trac/chicken/ticket/183>
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