| Type | Issue | Status | reviewed | Date | 8-Nov-2010 11:50 |
|---|---|---|---|---|---|
| Version | alpha 110 | Category | Native | Submitted by | Ladislav |
| Platform | All | Severity | minor | Priority | normal |
| Summary | FOREACH and its WORD argument |
|---|---|
| Description |
If the WORD argument of the FOREACH function is a block containing only set-words, FOREACH becomes an infinite loop. While it is usually trivial to not supply an "only set words" block as the WORD argument, sometimes the caller does not know what the contents of the WORD block are. In such a case it would be preferable if the loop did not become infinite. The example below illustrates such a case. |
| Example code |
use: func [
"Defines words local to a block."
vars [block! word!] "Local word(s) to the block"
body [block!] "Block to evaluate"
] [
do foreach (vars) reduce [none] reduce [body]
]
|
| Assigned to | n/a | Fixed in | - | Last Update | 7-Mar-2015 02:22 |
|---|
| Comments | |
|---|---|
|
(0003226)
BrianH 19-Feb-2012 19:33 |
FOREACH with just a set-word can be used for interesting tricks, but those are not very common, and WHILE does a better job of doing those same tricks. We changed PARSE's ANY and SOME to require forward motion, so it would be consistent to require FOREACH's word block to include at least one word! in it. |
|
(0004563)
szeng 27-Jan-2015 22:50 |
Fixed by: https://github.com/zsx/r3/commit/63115b1f6260b91b053737e698ff3b8c028b2980 |
|
(0004601)
szeng 7-Mar-2015 01:54 |
The above "fix" changes the semantics and breaks the code in r3-gui.r3:
unless foreach [here: hand] sys-hand [ if handler/priority > hand/priority [ insert here handler break/return true ] ] [ append sys-hand handler ] |
|
(0004602)
szeng 7-Mar-2015 02:22 |
Another try:
https://github.com/zsx/r3/commit/d4b51635983cb093774b7212c76671aaf3616f82 |
| Date | User | Field | Action | Change |
|---|---|---|---|---|
| 7-Mar-2015 02:22 | szeng | Comment : 0004602 | Added | - |
| 7-Mar-2015 01:54 | szeng | Comment : 0004601 | Modified | - |
| 7-Mar-2015 01:54 | szeng | Comment : 0004601 | Added | - |
| 27-Jan-2015 22:50 | szeng | Comment : 0004563 | Added | - |
| 19-Feb-2012 23:35 | Ladislav | Summary | Modified | FOREACH, and its WORD argument => FOREACH and its WORD argument |
| 19-Feb-2012 23:35 | Ladislav | Description | Modified | - |
| 19-Feb-2012 19:34 | BrianH | Category | Modified | Unspecified => Native |
| 19-Feb-2012 19:33 | BrianH | Comment : 0003226 | Added | - |
| 12-Nov-2010 05:26 | carl | Description | Modified | - |
| 12-Nov-2010 05:26 | carl | Code | Modified | - |
| 12-Nov-2010 05:26 | carl | Status | Modified | submitted => reviewed |
| 8-Nov-2010 11:50 | Ladislav | Ticket | Added | - |