Commit | Line | Data |
---|---|---|
7f918cf1 CE |
1 | MLtonExn |
2 | ======== | |
3 | ||
4 | [source,sml] | |
5 | ---- | |
6 | signature MLTON_EXN = | |
7 | sig | |
8 | val addExnMessager: (exn -> string option) -> unit | |
9 | val history: exn -> string list | |
10 | ||
11 | val defaultTopLevelHandler: exn -> 'a | |
12 | val getTopLevelHandler: unit -> (exn -> unit) | |
13 | val setTopLevelHandler: (exn -> unit) -> unit | |
14 | val topLevelHandler: exn -> 'a | |
15 | end | |
16 | ---- | |
17 | ||
18 | * `addExnMessager f` | |
19 | + | |
20 | adds `f` as a pretty-printer to be used by `General.exnMessage` for | |
21 | converting exceptions to strings. Messagers are tried in order from | |
22 | most recently added to least recently added. | |
23 | ||
24 | * `history e` | |
25 | + | |
26 | returns call stack at the point that `e` was first raised. Each | |
27 | element of the list is a file position. The elements are in reverse | |
28 | chronological order, i.e. the function called last is at the front of | |
29 | the list. | |
30 | + | |
31 | `history e` will return `[]` unless the program is compiled with | |
32 | `-const 'Exn.keepHistory true'`. | |
33 | ||
34 | * `defaultTopLevelHandler e` | |
35 | + | |
36 | function that behaves as the default top level handler; that is, print | |
37 | out the unhandled exception message for `e` and exit. | |
38 | ||
39 | * `getTopLevelHandler ()` | |
40 | + | |
41 | get the top level handler. | |
42 | ||
43 | * `setTopLevelHandler f` | |
44 | + | |
45 | set the top level handler to the function `f`. The function `f` | |
46 | should not raise an exception or return normally. | |
47 | ||
48 | * `topLevelHandler e` | |
49 | + | |
50 | behaves as if the top level handler received the exception `e`. |