CHICKEN Scheme

Metadata

Id: cb320323267f6688b8a05422dc762afa27d5cfd9
Trac id: 322
Type: task
Reporter: kon
Owner: felix
Cc: kon
Status: closed
Component: core libraries
Estimated difficulty:
Resolution: fixed
Priority: minor
Milestone:
Version: 4.6.x
Changetime: 2011-04-13 09:38:29 UTC
Created: 2010-08-10 02:45:52 UTC
Keywords: read-syntax keyword

Description

'|foo|: should be a keyword but is read as two items

'{foo:| should be a symbol but is a keyword

Changes and comments

[2010-08-11 14:30:50 UTC] felix changed type from defect to task

[2010-08-11 14:30:50 UTC] felix wrote:

Replying to kon: > '|foo|: should be a keyword but is read as two items > > '{foo:| should be a symbol but is a keyword >

(The latter is intended to be |foo:|, I assume?)

The SRFI-88 document requires this only for implementations that support SRFI-75, which chicken does not, so this is not a violation of the spec.

Now, would it be desirable adding support for the given examples?

[2010-08-15 04:43:00 UTC] kon set cc to kon

[2010-08-15 04:43:00 UTC] kon wrote:

Ok, but it seems a bit "lawyerly", given that the essence - quoted symbol - is implemented.

I don't remember what I was doing but I think I was bothered that there didn't seem a clear read syntax for a "quoted keyword". So, yes, desirable.

(I still think it a "defect", given my weaker logic, but low-priority in any case.)

[2010-08-17 21:56:00 UTC] felix set keywords to read-syntax keyword

[2010-08-17 21:56:00 UTC] felix removed milestone 4.6.0

[2010-08-17 21:56:00 UTC] felix wrote:

Replying to kon: > Ok, but it seems a bit "lawyerly", given that the essence - quoted symbol - is implemented. >

It certainly was a "lawyerly" reply.

> I don't remember what I was doing but I think I was bothered that there didn't seem a clear read syntax for a "quoted keyword". So, yes, desirable. > > (I still think it a "defect", given my weaker logic, but low-priority in any case.)

I don't think your logic is in any way weaker - I just have to ask how much of an annoyance this is. I check out the code and see if there can be a more consistent syntax be found.

[2010-08-17 21:56:05 UTC] felix changed status from new to assigned

[2010-08-17 21:56:05 UTC] felix set owner to felix

[2010-08-18 11:46:27 UTC] felix wrote:

I have changed the symbol reader 55ad083 to allow the following:

   (symbol->string '|abc def|)       =>   "abc def"
   (symbol->string '|abc||def|)      =>   "abcdef"
   (symbol->string '|abc|xyz|def|)   =>   "abcxyzdef"
   (symbol->string '|abc\|def|)      =>   "abc|def"
   (symbol->string 'abc\ def)        =>   "abc def"

`|abc:|` and `|abc|:` both will return a keyword. Is this acceptable?

[2010-08-20 04:02:22 UTC] kon wrote:

I really expected this to be "back burner". Wow, fun with quoted symbols.

SRFI-88 says |abc:| is a symbol & |abc|: is a keyword. This makes some sense. The "keyword quote" (':') is much like the quote - '|'foo| has printname "'foo" & '|abc:| has "foo:".

So, given the examples above, I think:

'|abc|:xyz|def|: is a keyword but '|abc|:xyz|def| is a symbol.

'abc\ def: is a keyword, since only the space is escaped .

'|abc|:|def| is a symbol & '|abc|:|def|: a keyword? This one is tricky because quoted symbol concatenation is an issue for people who don't like whitespace. Should '('|foo||bar|) be '('foo bar), as it is in Chicken 4.5.7 or '('foobar), as I guess it would be in 55ad083?

Seems the idea is if a "keyword quote" is directly outside of the symbol quote then a keyword. For Chicken, assuming keyword-style is #:prefix, ':|abc|xyz|def| is a keyword & '|abc|xyz|def|: is two tokens? When keyword-style is #:suffix, ':|abc|xyz|def| is two tokens?

What about '|abc|:|def| & prefix keywords? A quoted symbol & a keyword? Just a quoted symbol?

(Still kinda think this is a lower priority.)

Summary