[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Sorry, last formatted list object should not have been quoted:
=> "(10 3 +) #e+12.000 a str (3 #\\s \"string\")"
> From: Paul Schlie <schlie@xxxxxxxxxxx>
> Date: Tue, 30 Mar 2004 09:32:21 -0500
> To: <srfi-54@xxxxxxxxxxxxxxxxx>
> Subject: Re: feedback
> Resent-From: srfi-54@xxxxxxxxxxxxxxxxx
> Resent-Date: Tue, 30 Mar 2004 16:32:35 +0200 (DFT)
> Please consider:
> - personally believe fmt-xxx should produce a string (or lazy stream) where
> a quoted scheme object, when displayed and then read back, would would be
> equivalent, if not quoted, it's simply evaluated and then correspondingly
> treated. which I suspect would be more generally useful and intuitive:
> - Per your example below:
> (fmt-str a (fmt-num 12 -t s: '+ f: 3) " " #\a " str " '(3 #\s "string"))
> => "(10 3 +) #e+12.000 a str '(3 #\\s \"string\")"
> note: where fmt parameters have the form of:
> -X if parameter-less, i.e. -t for display type prefix
> X: if parameterized, i.e. s: <sign> or f: <fraction-digits>
> - the value of fmt-xxx potentially yielding/consuming ports (or streams),
> is that it enables lazily evaluated arbitrary length hierarchically
> specified format specifications; which would likely be otherwise
> potentially physically impractical to achieve.
> (which format does not enable)
> Thanks, -paul-
>> From: soo <tilde@xxxxxxxxxxx>
>> In SRFI-48 mailing list, Marc Feeley said:
>> To make printing easier, a general purpose function called "print"
>> could be added with this definition:
>> (define (print . lst) (for-each display lst))
>> (print "list: " (field '(one "two" 3)))
>> Likewise, we can make a procedure:
>> (define (cat . objects)
>> (let ((string-port (open-output-string)))
>> (for-each (lambda (object)
>> (display object string-port))
>> (cat 12 " " #\a " str " '(3 #\s "string"))
>> (fmt 12 " " (fmt #\a) " str " (fmt '(3 #\s "string")))
>> => "12 a str (3 s string)"
>> (define a '(10 3 +))
>> (cat a (fmt 12 10 3 '+) " " #\a " str " (fmt '(3 #\s "string") write))
>> (cat a (apply fmt 12 a) " " #\a " str " (fmt '(3 #\s "string") write))
>> (fmt a (fmt 12 10 3 '+) " " (fmt #\a) " str " (fmt '(3 #\s "string") write))
>> => "(10 3 +) #e+12.000 a str (3 #\\s \"string\")"
>> | - as observed in the earlier srfi-48 discussions, it may even be better
>> | (both more general, and efficient) to define that resulting format
>> | yield string-ports, rather than strings; which could then even be made more
>> | general if formatting functions themselves were able to accept
>> | such that more complex hierarchically defined formats may be defined as
>> | desired.
>> FMT manipulates not string ports but strings.
>> If we have a procedure like `open-output-string?', we can make FMT to append
>> the strings in the string ports to the resulting string like <string>
>> Additionally, even though FMT is not fully extensible, If <output-port>
>> parameter is added to FMT, it can print the resulting string like FORMAT, and
>> If <input-port> parameter is added, `file->string' function can be added, and
>> If <separator> parameter is added like '(#\, 3), comma separator function can
>> be added.
>> | - lastly, although personally I too would like format specifications to be
>> | as succinct as possible, I suspect that all format specifications
>> | more than a single specifier should be tagged with at least a single letter
>> | semi-descriptive symbol to both give a hint as to what the specified
>> | controls, and to enable them to be only defined as required in arbitrary
>> | ordered lists as convenient to the author, and/or to enable their more
>> | flexible construction.
>> I'll consider it, if conflicts occur among the format specifications.
>> Anyway, I think it leaves some room for consideration.
>> | With a little luck, the above is hopefully also be consistent with your
>> | goals for this srfi as well?
>> | -paul-