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Source for ticket #503

cc

changetime

2013-07-07 03:20:44

component

WG1 - Core

description

Andy Wingo writes:

  There are also a number of minor points about the WG1 draft that I feel were not dealt with in a satisfactory way.  A few things come to mind: [...] the insistence on "an unspecified value" rather than allowing 0 values.

Alaric Snell-Pym, Emmanuel Medernach, and Aaron Hsu made similar remarks.

R6RS provides this option, allowing setter-type procedures as well as `set!` itself to return an unspecified number of unspecified values.  The WG, however, was swayed by the argument of Alex Shinn that allowing zero values to be returned means that completely unknown procedures cannot be safely called except by wrapping each call in a `call-with-values`.

In principle, this problem cannot be eliminated as long as returning multiple values is possible at all, but eliminating the theoretical possibility of standard setter procedures to return other than one value (something which no R6RS implementation actually does) makes it less likely to occur.

id

keywords

milestone

owner

alexshinn

priority

major

reporter

cowan

resolution

wontfix

severity

status

closed

summary

Setters should be allowed to return zero values

time

2013-05-13 00:24:57

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

raw-time

1373142044410382

ticket

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

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

time

2013-07-07 03:20:44

Change at time 2013-05-13 09:11:43

author

cowan

field

comment

newvalue

oldvalue

raw-time

1368411103150170

ticket

time

2013-05-13 09:11:43

Change at time 2013-05-13 09:11:43

author

cowan

field

description

newvalue

Andy Wingo writes:

  There are also a number of minor points about the WG1 draft that I feel were not dealt with in a satisfactory way.  A few things come to mind: [...] the insistence on "an unspecified value" rather than allowing 0 values.

Alaric Snell-Pym, Emmanuel Medernach, and Aaron Hsu made similar remarks.

R6RS provides this option, allowing setter-type procedures as well as `set!` itself to return an unspecified number of unspecified values.  The WG, however, was swayed by the argument of Alex Shinn that allowing zero values to be returned means that completely unknown procedures cannot be safely called except by wrapping each call in a `call-with-values`.

In principle, this problem cannot be eliminated as long as returning multiple values is possible at all, but eliminating the theoretical possibility of standard setter procedures to return other than one value (something which no R6RS implementation actually does) makes it less likely to occur.

oldvalue

Andy Wingo writes:

  There are also a number of minor points about the WG1 draft that I feel were not dealt with in a satisfactory way.  A few things come to mind: [...] the insistence on "an unspecified value" rather than allowing 0 values.

Alaric Snell-Pym and Emmanuel Medernach made similar remarks.

R6RS provides this option, allowing setter-type procedures as well as `set!` itself to return an unspecified number of unspecified values.  The WG, however, was swayed by the argument of Alex Shinn that allowing zero values to be returned means that completely unknown procedures cannot be safely called except by wrapping each call in a `call-with-values`.

In principle, this problem cannot be eliminated as long as returning multiple values is possible at all, but eliminating the theoretical possibility of standard setter procedures to return other than one value (something which no R6RS implementation actually does) makes it less likely to occur.

raw-time

1368411103150170

ticket

time

2013-05-13 09:11:43

Change at time 2013-05-13 08:19:06

author

cowan

field

comment

newvalue

oldvalue

raw-time

1368407946250443

ticket

time

2013-05-13 08:19:06

Change at time 2013-05-13 08:19:06

author

cowan

field

description

newvalue

Andy Wingo writes:

  There are also a number of minor points about the WG1 draft that I feel were not dealt with in a satisfactory way.  A few things come to mind: [...] the insistence on "an unspecified value" rather than allowing 0 values.

Alaric Snell-Pym and Emmanuel Medernach made similar remarks.

R6RS provides this option, allowing setter-type procedures as well as `set!` itself to return an unspecified number of unspecified values.  The WG, however, was swayed by the argument of Alex Shinn that allowing zero values to be returned means that completely unknown procedures cannot be safely called except by wrapping each call in a `call-with-values`.

In principle, this problem cannot be eliminated as long as returning multiple values is possible at all, but eliminating the theoretical possibility of standard setter procedures to return other than one value (something which no R6RS implementation actually does) makes it less likely to occur.

oldvalue

Andy Wingo writes:

  There are also a number of minor points about the WG1 draft that I feel were not dealt with in a satisfactory way.  A few things come to mind: [...] the insistence on "an unspecified value" rather than allowing 0 values.

Alaric Snell-Pym made a similar remark.

R6RS provides this facility, allowing setter-type procedures, as well as `set!` itself, to return an unspecified number of unspecified values.  The WG, however, was swayed by the argument of Alex Shinn that allowing zero values to be returned means that completely unknown procedures cannot be safely called except by wrapping each call in a `call-with-values`.  In principle, this problem cannot be eliminated as long as returning multiple values is possible at all, but eliminating the theoretical possibility of standard setter procedures to return other than one value (something which no R6RS implementation actually does) makes it less likely to occur.

raw-time

1368407946250443

ticket

time

2013-05-13 08:19:06

Change at time 2013-05-13 01:20:39

author

cowan

field

comment

newvalue

oldvalue

raw-time

1368382839838993

ticket

time

2013-05-13 01:20:39

Change at time 2013-05-13 01:20:39

author

cowan

field

description

newvalue

Andy Wingo writes:

  There are also a number of minor points about the WG1 draft that I feel were not dealt with in a satisfactory way.  A few things come to mind: [...] the insistence on "an unspecified value" rather than allowing 0 values.

Alaric Snell-Pym made a similar remark.

R6RS provides this facility, allowing setter-type procedures, as well as `set!` itself, to return an unspecified number of unspecified values.  The WG, however, was swayed by the argument of Alex Shinn that allowing zero values to be returned means that completely unknown procedures cannot be safely called except by wrapping each call in a `call-with-values`.  In principle, this problem cannot be eliminated as long as returning multiple values is possible at all, but eliminating the theoretical possibility of standard setter procedures to return other than one value (something which no R6RS implementation actually does) makes it less likely to occur.

oldvalue

Andy Wingo writes:

  There are also a number of minor points about the WG1 draft that I feel were not dealt with in a satisfactory way.  A few things come to mind: [...] the insistence on "an unspecified value" rather than allowing 0 values.

R6RS provides this facility, allowing setter-type procedures, as well as `set!` itself, to return an unspecified number of unspecified values.  The WG, however, was swayed by the argument of Alex Shinn that

raw-time

1368382839838993

ticket

time

2013-05-13 01:20:39