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| author | Joey Hess <joeyh@joeyh.name> | 2016-03-19 14:48:37 -0400 |
|---|---|---|
| committer | Joey Hess <joeyh@joeyh.name> | 2016-03-19 14:48:37 -0400 |
| commit | 8ecaa473156a847c343b7356c5a7a146d7a73176 (patch) | |
| tree | 87849c1d1cede6600c523ee5076609196a18cca7 | |
| parent | c5282cc38c1891580fe1ecd751c2d8e4d841a291 (diff) | |
comment
| -rw-r--r-- | doc/todo/type_level_OS_requirements/comment_9_8d2153620518295f33b83f1506441fdd._comment | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/doc/todo/type_level_OS_requirements/comment_9_8d2153620518295f33b83f1506441fdd._comment b/doc/todo/type_level_OS_requirements/comment_9_8d2153620518295f33b83f1506441fdd._comment new file mode 100644 index 00000000..6f4128e2 --- /dev/null +++ b/doc/todo/type_level_OS_requirements/comment_9_8d2153620518295f33b83f1506441fdd._comment @@ -0,0 +1,23 @@ +[[!comment format=mdwn + username="joey" + subject="""comment 9""" + date="2016-03-19T18:35:20Z" + content=""" +I'm currently using a simple sum type to describe the target OS: + + data OS = OSDebian | OSBuntish | OSFreeBSD + +This could in theory specify much more information about the +OS version and architecture. +Even type-level strings could be used to include release names. + +But, the old version of ghc being targeted doesn't have the nice +Data.Type.Equality stuff; I had to implement my own clumsily +and it would quickly hit a combinatorial explosion with more data. + +(There may be a better way than the way I found which works back to ghc 7.6.3.) + +Of course, we can always add more detail later. Since type aliases are +used, `Propety Debian` which only specifies `OSDebian` now, could easily +be changed at some point to specify `OSDebian AnyVersion AnyArch`. +"""]] |