This site is a static rendering of the Trac instance that was used by R7RS-WG1 for its work on R7RS-small (PDF), which was ratified in 2013. For more information, see Home.

Source for ticket #273

cc


    
changetime

    
2011-09-23 23:45:53

    
component

    
WG1 - Core

    
description

    
In the section <Output>, in the description of `write', we say:

  Symbols that contain non-ASCII characters are escaped either with inline hex escapes or with vertical bars.

Is this right?  Shouldn't implementations that support Unicode be allowed to write symbols that contain non-ASCII characters without treating them specially?

The invariant we want to establish is that `read' can read what `write' has written.

The question for this ticket is whether the standard should require that that invariant hold only in the same implementation, or across implementations.

If we stick with the existing language, we get interoperability across implementations.

If we change the language to allow any non-whitespace character supported by the implementation to be written unescaped and without vertical bars, we lose interoperability across implementations, but gain the ability of the implementation to display symbols containing Unicode characters in a natural manner.

    
id

    
273

    
keywords

    

    
milestone

    

    
owner

    
alexshinn

    
priority

    
major

    
reporter

    
aag

    
resolution

    
wontfix

    
severity

    

    
status

    
closed

    
summary

    
Decide whether the presence of non-ASCII characters in symbols requires escaping or using vertical bars when output by `write'.

    
time

    
2011-08-29 18:48:22

    
type

    
defect

    
Changes

    
Change at time 2011-09-23 23:45:53

    
author

    
cowan

    
field

    
comment

    
newvalue

    

    
oldvalue

    
5

    
raw-time

    
1316796353000000

    
ticket

    
273

    
time

    
2011-09-23 23:45:53

    
Change at time 2011-09-23 23:45:53

    
author

    
cowan

    
field

    
resolution

    
newvalue

    
wontfix

    
oldvalue

    

    
raw-time

    
1316796353000000

    
ticket

    
273

    
time

    
2011-09-23 23:45:53

    
Change at time 2011-09-23 23:45:53

    
author

    
cowan

    
field

    
status

    
newvalue

    
closed

    
oldvalue

    
new

    
raw-time

    
1316796353000000

    
ticket

    
273

    
time

    
2011-09-23 23:45:53

    
Change at time 2011-09-23 23:45:35

    
author

    
cowan

    
field

    
comment

    
newvalue

    
I'm closing this ticket because we no longer have to decide this.

    
oldvalue

    
4

    
raw-time

    
1316796335000000

    
ticket

    
273

    
time

    
2011-09-23 23:45:35

    
Change at time 2011-08-30 06:09:14

    
author

    
cowan

    
field

    
comment

    
newvalue

    
UnicodeCowan 15 doesn't fly; it winds up assigning the pname "a\\xbb0;b" to the symbol a\xbb0;b as well as a\x5c;xbb0\x3b;b, which is intolerable.

So I withdraw my objections.

    
oldvalue

    
3

    
raw-time

    
1314659354000000

    
ticket

    
273

    
time

    
2011-08-30 06:09:14

    
Change at time 2011-08-30 04:46:21

    
author

    
cowan

    
field

    
comment

    
newvalue

    
Alex is mistaken as things stand.  See #274.

    
oldvalue

    
2

    
raw-time

    
1314654381000000

    
ticket

    
273

    
time

    
2011-08-30 04:46:21

    
Change at time 2011-08-30 03:57:38

    
author

    
aag

    
field

    
comment

    
newvalue

    
Alex points out:

If some other implementation doesn't support the Greek
subset of Unicode, then they wouldn't support it even
if it were escaped.

    
oldvalue

    
1

    
raw-time

    
1314651458000000

    
ticket

    
273

    
time

    
2011-08-30 03:57:38