| Type | Wish | Status | complete | Date | 10-Feb-2010 08:59 |
|---|---|---|---|---|---|
| Version | alpha 97 | Category | Documentation | Submitted by | Ladislav |
| Platform | All | Severity | minor | Priority | normal |
| Summary | The "throws an error" idiom used in documentation |
|---|---|
| Description |
In the current documentation, there is a lot of places, where the above idiom is used. I find it confusing. See the code examples below. Since the behaviour is not equivalent, the idioms "an error was caused (or, an error was triggered, if you prefer)" and "an error was thrown" should not be used interchangeably. |
| Example code |
do-example: func [code [block!]] [
try/except [if error? catch code ["an error was thrown"]] ["an error was caused"]
]
; example #1
do-example [1 / 0]
; == "an error was caused"
; example #2
do-example [throw make error! ""]
; == "an error was thrown"
|
| Assigned to | n/a | Fixed in | - | Last Update | 18-Aug-2013 13:53 |
|---|
| Comments | |
|---|---|
|
(0002021)
BrianH 11-Feb-2010 19:15 |
This is another R2'ism that should be reworded. There is a distinction between making an error and causing the error to be thrown (though not by THROW, hence the confusion). Perhaps "triggered"? |
|
(0002025)
Ladislav 13-Feb-2010 04:25 |
I do not see it as an R2-ism. In R2 the same distinction exists. "An error is thrown" - certainly, it is used in CS, but it does not look adequate in Rebol where the Throw function exists and does something else. |
|
(0002026)
BrianH 14-Feb-2010 02:06 |
Strangely enough, THROW, RETURN, EXIT, HALT and QUIT use exactly the same mechanism as error triggering in R3 - just different error codes. Errors really are thrown in R3 when they are triggered, the same way that THROW throws values. This is probably not true in R2, but there the THROW function is explicitly called to throw errors within functions with a [catch] attribute (hence the "R2'ism" comment).
But for the average REBOL developer that might be confusing, a matter of low-level R3 trivia. Changing the docs to use less confusing terms makes sense, even when they are technically accurate now. |
|
(0002030)
Ladislav 15-Feb-2010 16:27 |
"...just different error codes...", yes, and not *just* that. That (as well as the above examples) is what I describe saying "the Throw function does something else", than a Do (trigger) function would do, when obtaining an error as an argument value. |
|
(0003468)
Ladislav 19-Feb-2013 14:47 |
Pull request submitted. |
| Date | User | Field | Action | Change |
|---|---|---|---|---|
| 18-Aug-2013 13:53 | Ladislav | Status | Modified | pending => complete |
| 19-Feb-2013 14:47 | Ladislav | Status | Modified | reviewed => pending |
| 19-Feb-2013 14:47 | Ladislav | Comment : 0003468 | Added | - |
| 9-Mar-2010 10:25 | Ladislav | Description | Modified | - |
| 9-Mar-2010 10:24 | Ladislav | Comment : 0002025 | Modified | - |
| 15-Feb-2010 16:28 | Ladislav | Comment : 0002030 | Modified | - |
| 15-Feb-2010 16:27 | Ladislav | Comment : 0002030 | Added | - |
| 14-Feb-2010 02:06 | BrianH | Comment : 0002026 | Added | - |
| 13-Feb-2010 04:25 | Ladislav | Comment : 0002025 | Added | - |
| 11-Feb-2010 19:15 | BrianH | Comment : 0002021 | Added | - |
| 11-Feb-2010 19:12 | BrianH | Status | Modified | submitted => reviewed |
| 10-Feb-2010 09:12 | Ladislav | Description | Modified | - |
| 10-Feb-2010 09:12 | Ladislav | Code | Modified | - |
| 10-Feb-2010 08:59 | Ladislav | Ticket | Added | - |