45 lines
1.8 KiB
Nix
45 lines
1.8 KiB
Nix
{ lib }:
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{ # haskellPathsInDir : Path -> Map String Path
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# A map of all haskell packages defined in the given path,
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# identified by having a cabal file with the same name as the
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# directory itself.
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haskellPathsInDir = root:
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let # Files in the root
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root-files = builtins.attrNames (builtins.readDir root);
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# Files with their full paths
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root-files-with-paths =
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map (file:
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{ name = file; value = root + "/${file}"; }
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) root-files;
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# Subdirectories of the root with a cabal file.
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cabal-subdirs =
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builtins.filter ({ name, value }:
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builtins.pathExists (value + "/${name}.cabal")
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) root-files-with-paths;
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in builtins.listToAttrs cabal-subdirs;
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# locateDominatingFile : RegExp
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# -> Path
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# -> Nullable { path : Path;
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# matches : [ MatchResults ];
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# }
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# Find the first directory containing a file matching 'pattern'
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# upward from a given 'file'.
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# Returns 'null' if no directories contain a file matching 'pattern'.
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locateDominatingFile = pattern: file:
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let go = path:
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let files = builtins.attrNames (builtins.readDir path);
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matches = builtins.filter (match: match != null)
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(map (builtins.match pattern) files);
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in
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if builtins.length matches != 0
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then { inherit path matches; }
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else if path == /.
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then null
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else go (dirOf path);
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parent = dirOf file;
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isDir =
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let base = baseNameOf file;
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type = (builtins.readDir parent).${base} or null;
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in file == /. || type == "directory";
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in go (if isDir then file else parent);
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}
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