move git comparison to related work
it should be pulled out of the branch before we go for merging
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@ -31,29 +31,6 @@ In particular, every file system object falls into these three cases:
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A bare file or symlink as the "root" file system object is allowed.
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### Comparison with Git
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This is close to Git's model, but with one crucial difference:
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Git puts the "permission" info within the directory map's values instead of making it part of the file (blob, in it's parlance) object.
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data GitObject
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= Blob ByteString
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| Tree (Map FileName (Persission, FSO))
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data Persission
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= Directory -- IFF paired with tree
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-- Iff paired with blob, one of:
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| RegFile
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| ExecutableFile
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| Symlink
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So long as the root object is a directory, the representations are isomorphic.
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There is no "wiggle room" the git way since whenever the permission info wouldn't matter (e.g. the child object being mapped to is a directory), the permission info must be a sentinel value.
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However, if the root object is a blob, there is loss of fidelity.
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Since the permission info is used to distinguish executable files, non-executable files, and symlinks, but there isn't a "parent" directory of the root to contain that info, these 3 cases cannot be distinguished.
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Git's model matches Unix tradition, but Nix's model is more natural.
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## References
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@ -25,6 +25,30 @@ Do we have open terms?
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Do we hve thunks vs expressions distinction?
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c.f. John Shutt's modern fexprs, when the syntax can "leak".
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## Comparison with Git file system model
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This is close to Git's model, but with one crucial difference:
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Git puts the "permission" info within the directory map's values instead of making it part of the file (blob, in it's parlance) object.
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data GitObject
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= Blob ByteString
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| Tree (Map FileName (Persission, FSO))
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data Persission
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= Directory -- IFF paired with tree
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-- Iff paired with blob, one of:
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| RegFile
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| ExecutableFile
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| Symlink
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So long as the root object is a directory, the representations are isomorphic.
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There is no "wiggle room" the git way since whenever the permission info wouldn't matter (e.g. the child object being mapped to is a directory), the permission info must be a sentinel value.
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However, if the root object is a blob, there is loss of fidelity.
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Since the permission info is used to distinguish executable files, non-executable files, and symlinks, but there isn't a "parent" directory of the root to contain that info, these 3 cases cannot be distinguished.
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Git's model matches Unix tradition, but Nix's model is more natural.
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## Machine models
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TODO
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