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Source for ticket #391
cc
changetime
2012-10-07 03:57:52
component
WG1 - Core
description
R7RS requires an error to be signalled (which means an exception is raised as if by `raise`) in the following circumstances:
1. Trying to open for input or delete a file that does not exist or is otherwise inaccessible.
1. Specifying an argument to `scheme-report-environment` that the implementation doesn't support. (It must support 7 and may support other values.)
1. An EOF is encountered while `read` is in the middle of a datum.
1. Using `expt` to raise zero to the power of a non-real number (alternatively an arbitrary number may be returned).
This proposal is to provide four standard predicates that identify these specific conditions, to be used in `guard` clauses or in `with-exception` handlers as a portable means of detecting these errors. Although these predicates may return `#t` on other objects, if one reports `#t` on an object, the others must report `#f`. Proposed names are `file-error?`, `scheme-report-error?`, `read-error?`, and `expt-error?` respectively.
id
391
keywords
milestone
owner
cowan
priority
major
reporter
cowan
resolution
fixed
severity
status
closed
summary
Add predicates for R7RS signalled conditions
time
2012-05-13 11:37:39
type
defect
Changes
Change at time 2012-10-07 03:57:52
author
cowan
field
comment
newvalue
WG1 adopted `file-error?` and `read-error?`. `Expt-error?` was defined away, and with the decision to relegate `scheme-report-environment` to the R5RS compatibility library only, it no longer made sense to try to catch this error.
oldvalue
5
raw-time
1349557072209122
ticket
391
time
2012-10-07 03:57:52
Change at time 2012-10-07 03:57:52
author
cowan
field
resolution
newvalue
fixed
oldvalue
raw-time
1349557072209122
ticket
391
time
2012-10-07 03:57:52
Change at time 2012-10-07 03:57:52
author
cowan
field
status
newvalue
closed
oldvalue
writing
raw-time
1349557072209122
ticket
391
time
2012-10-07 03:57:52
Change at time 2012-08-27 04:59:18
author
cowan
field
comment
newvalue
oldvalue
4
raw-time
1346018358909053
ticket
391
time
2012-08-27 04:59:18
Change at time 2012-08-27 04:59:18
author
cowan
field
owner
newvalue
cowan
oldvalue
alexshinn
raw-time
1346018358909053
ticket
391
time
2012-08-27 04:59:18
Change at time 2012-08-27 04:59:18
author
cowan
field
status
newvalue
writing
oldvalue
decided
raw-time
1346018358909053
ticket
391
time
2012-08-27 04:59:18
Change at time 2012-08-26 23:13:32
author
cowan
field
comment
newvalue
WG1 voted to adopt this proposal.
oldvalue
3
raw-time
1345997612049612
ticket
391
time
2012-08-26 23:13:32
Change at time 2012-08-26 23:13:32
author
cowan
field
status
newvalue
decided
oldvalue
new
raw-time
1345997612049612
ticket
391
time
2012-08-26 23:13:32
Change at time 2012-07-07 03:23:20
author
cowan
field
comment
newvalue
oldvalue
2
raw-time
1341606200607448
ticket
391
time
2012-07-07 03:23:20
Change at time 2012-07-07 03:23:20
author
cowan
field
description
newvalue
R7RS requires an error to be signalled (which means an exception is raised as if by `raise`) in the following circumstances:
1. Trying to open for input or delete a file that does not exist or is otherwise inaccessible.
1. Specifying an argument to `scheme-report-environment` that the implementation doesn't support. (It must support 7 and may support other values.)
1. An EOF is encountered while `read` is in the middle of a datum.
1. Using `expt` to raise zero to the power of a non-real number (alternatively an arbitrary number may be returned).
This proposal is to provide four standard predicates that identify these specific conditions, to be used in `guard` clauses or in `with-exception` handlers as a portable means of detecting these errors. Although these predicates may return `#t` on other objects, if one reports `#t` on an object, the others must report `#f`. Proposed names are `file-error?`, `scheme-report-error?`, `read-error?`, and `expt-error?` respectively.
oldvalue
R7RS requires an error to be signalled (which means an exception is raised as if by `raise`) in the following circumstances:
1. Trying to open for input or delete a file that does not exist or is otherwise inaccessible.
1. Specifying an argument to `scheme-report-environment` that the implementation doesn't support. (It must support 7 and may support other values.)
1. An EOF is encountered while `read` is in the middle of a datum.
1. Using `expt` to raise zero to the power of a non-real number (alternatively an arbitrary number may be returned).
This proposal is to provide four standard predicates that identify these specific conditions, to be used in `guard` clauses or in `with-exception` handlers as a portable means of detecting these errors. Although these predicates may return `#t` on other objects, if one reports `#t` on an object, the others must report `#f`. Proposed names are `filename-error?`, `scheme-report-error?`, `read-error?`, and `expt-error?` respectively.
raw-time
1341606200607448
ticket
391
time
2012-07-07 03:23:20
Change at time 2012-05-15 03:49:45
author
cowan
field
comment
newvalue
oldvalue
1
raw-time
1337028585063744
ticket
391
time
2012-05-15 03:49:45
Change at time 2012-05-15 03:49:45
author
cowan
field
description
newvalue
R7RS requires an error to be signalled (which means an exception is raised as if by `raise`) in the following circumstances:
1. Trying to open for input or delete a file that does not exist or is otherwise inaccessible.
1. Specifying an argument to `scheme-report-environment` that the implementation doesn't support. (It must support 7 and may support other values.)
1. An EOF is encountered while `read` is in the middle of a datum.
1. Using `expt` to raise zero to the power of a non-real number (alternatively an arbitrary number may be returned).
This proposal is to provide four standard predicates that identify these specific conditions, to be used in `guard` clauses or in `with-exception` handlers as a portable means of detecting these errors. Although these predicates may return `#t` on other objects, if one reports `#t` on an object, the others must report `#f`. Proposed names are `filename-error?`, `scheme-report-error?`, `read-error?`, and `expt-error?` respectively.
oldvalue
R7RS requires an error to be signalled (which means an exception is raised as if by `raise`) in the following circumstances:
1. Trying to open for input or delete a file that does not exist or is otherwise inaccessible.
1. Specifying an argument to `scheme-report-environment` that the implementation doesn't support. (It must support 7 and may support other values.)
1. An EOF is encountered while `read` is in the middle of a datum.
1. Using `expt` to raise zero to the power of a non-real number.
This proposal is to provide four standard predicates that identify these specific conditions, to be used in `guard` clauses or in `with-exception` handlers as a portable means of detecting these errors. Although these predicates may return `#t` on other objects, if one reports `#t` on an object, the others must report `#f`. Proposed names are `filename-error?`, `scheme-report-error?`, `read-error?`, and `expt-error?` respectively.
raw-time
1337028585063744
ticket
391
time
2012-05-15 03:49:45