Add an option to hide common tags

README.md

@@ -7,9 +7,12 @@ This allows for easy filtering of tagged files (e.g. '/mountpoint/tag1/tag2/' co
 See [example.md](example.md).
 
 ## Usage
-`usage: dtagfs <source> <mount point> [-f] [-o option[,options...]]`
+```text
+usage: dtagfs <source> <mount point> [-f] [-o option[,options...]]`
 
 -f: foreground (don't fork to background)
+-o nocomm: don't show tags that all files in a directory have in common
+```
 
 ## Supported tag sources
 * Dublin Core (XMP), via [exempi-d](https://github.com/lesderid/exempi-d)

source/app.d

@@ -3,6 +3,7 @@ module dtagfs.app;
 import std.stdio;
 import std.getopt;
 import std.array;
+import std.algorithm;
 
 import dfuse.fuse;
 
@@ -40,7 +41,14 @@ void main(string[] args)
 
 FileSystem mount(string source, string mountPoint, TagProvider[] tagProviders, string[] options, bool foreground)
 {
-	auto filesystem = new FileSystem(source, tagProviders);
+	auto noCommon = false;
+	if(options.canFind("nocomm"))
+	{
+		options = options.remove!(a => a == "nocomm");
+		noCommon = true;
+	}
+
+	auto filesystem = new FileSystem(source, tagProviders, noCommon);
 
 	auto fuse = new Fuse("dtagfs", foreground, false);
 	fuse.mount(filesystem, mountPoint, options);

source/filesystem.d

@@ -30,11 +30,15 @@ class FileSystem : Operations
 	private string[] _tagList;
 	private string[string] _fileLinkCache;
 
-	this(string source, TagProvider[] tagProviders)
+	private bool _noCommon;
+
+	this(string source, TagProvider[] tagProviders, bool noCommon)
 	{
 		_source = source;
 		_tagProviders = tagProviders;
 
+		_noCommon = noCommon;
+
 		lstat(toStringz(source), &_sourceStat);
 
 		cacheTags();
@@ -117,11 +121,11 @@ class FileSystem : Operations
 		{
 			auto tags = pathSplitter(path).array[1..$];
 
-			return _tagCache.byKeyValue()
-				.filter!(a => tags.all!(b => a.value.canFind(b)))
-				.map!(a => a.value)
+			auto filePairs = _tagCache.byKeyValue().filter!(a => tags.all!(b => a.value.canFind(b)));
+			return filePairs.map!(a => a.value)
 				.joiner
 				.filter!(a => !tags.canFind(a))
+				.filter!(a => !_noCommon || !filePairs.all!(f => f.value.canFind(a)))
 				.array
 				.sort()
 				.uniq
@@ -173,7 +177,6 @@ class FileSystem : Operations
 			return _dirCache[path];
 		}
 
-		//TODO: Don't return tags if only one file (or files with exactly the same set of tags)?
 		if (path == "/")
 		{
 			return _dirCache[path] = getTags(path) ~ getFiles(path);