Inconsistent Behavior of Lists

Richard Gaskin ambassador at fourthworld.com
Wed Sep 15 20:54:45 EDT 2004


Dan Shafer wrote:

> A list should be seen as a comma-delimited data container where commas 
> separate data elements. Spaces after commas should not be significant. 
> They aren't in any other language I know of that processes list data 
> structures. a="1",b="2" and a="1", b="2" should be identical. In Rev, 
> they are not. Rev sees the first element of the second item  as " b", 
> which makes no syntactic sense as far as I can tell.

It's arguably more consistent than other implementations that play fast 
and loose with their delimiters.  In these other languages, an item 
delimiter is either a comma or a combination of comma+space, or perhaps 
even comma+space+space and comma+space+return (is it all white space or 
just ASCII 32 that gets overlooked?).

Transcript is more consistent:  an item delimiter is a single character, 
and anything that falls between those delimiters is considered part of 
the data.  It works the same regardless of the delimiter, and does not 
attempt to second-guess whether other characters are significant or not.

Transcript also provides the "word" chunk type, so you can also parse 
item contents in a way that conveniently strips out space characters.

So at least with Transcript you can have it both ways.  I'm not sure how 
one would handle significant space characters in a language that decided 
  for you that they weren't significant.

--
  Richard Gaskin
  Fourth World Media Corporation
  __________________________________________________
  Rev tools and more: http://www.fourthworld.com/rev


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