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 #515
cc
changetime
2013-07-07 03:20:44
component
WG1 - Core
description
Aaron Hsu writes:
I am very leery of the `cond-expand` form, and I believe that it also fails to scale well. We have done little to fix the issues in using and making `cond-expand` useful. We have also ignored fundamentally more flexible and useful forms.
id
515
keywords
milestone
owner
alexshinn
priority
major
reporter
cowan
resolution
wontfix
severity
status
closed
summary
Cond-expand doesn't scale and is hard to use
time
2013-05-13 08:39:23
type
defect
Changes
Change at time 2013-07-07 03:20:44
author
cowan
field
comment
newvalue
The WG decided by unanimous consent to take no action on this ticket.
oldvalue
4
raw-time
1373142044410382
ticket
515
time
2013-07-07 03:20:44
Change at time 2013-07-07 03:20:44
author
cowan
field
resolution
newvalue
wontfix
oldvalue
raw-time
1373142044410382
ticket
515
time
2013-07-07 03:20:44
Change at time 2013-07-07 03:20:44
author
cowan
field
status
newvalue
closed
oldvalue
new
raw-time
1373142044410382
ticket
515
time
2013-07-07 03:20:44
Change at time 2013-05-21 01:28:08
author
cowan
field
comment
newvalue
Ah, thanks. Providing a run-time procedure that affects compile-time behavior is to create a phasing problem similar to those we have banished by excluding low-level macros and readtables that affect code. I'd hate to see phasing raise its ugly head in the small language.
oldvalue
3
raw-time
1369074488813485
ticket
515
time
2013-05-21 01:28:08
Change at time 2013-05-13 11:03:00
author
arcfide
field
comment
newvalue
I say that `cond-expand` fails to scale well because it fails to provide a simple, program accessible method for extending and defining the set of constants that it recognizes.
oldvalue
2
raw-time
1368417780766873
ticket
515
time
2013-05-13 11:03:00
Change at time 2013-05-13 08:41:14
author
cowan
field
comment
newvalue
I don't know how to interpret the first two sentences. I assume the third sentence refers to the `meta-cond` proposal (essentially a `cond` using syntax-time variables and values), but the problem with that is that it depends heavily on what names are taken to be in scope at compile time, which is highly implementation-dependent. Because `cond-expand` recognizes only constants fixed by the implementation (plus which libraries are available for import, also basically fixed), it has no such phasing difficulties.
oldvalue
1
raw-time
1368409274917148
ticket
515
time
2013-05-13 08:41:14