Improve formatting other error message types, simplify TreeFilter cod…

…e a bit

README.md

@@ -8,11 +8,17 @@ View [the full documentation](https://harris-chris.github.io/tree-surgeon/)
 
 Tree surgeon is a tool for applying complex (or simple!) filters to directory trees. For example:
 ```
-$ tree-surgeon show-diff -f 'endsWith ".md" (basename file)' -s ~/Documents
+$ tree-surgeon tree-diff -f 'endsWith ".md" (basename file)' -s ~/Documents
 ```
 will show a before & after of your `~/Downloads` folder, if all but the markdown (`*.md`) files were filtered out, then
 ```
-$ tree-surgeon to-bash -f 'endsWith ".md" (basename file)' -s ~/Documents | elem parents myProjectFiles
-$
+$ tree-surgeon to-bash -f 'endsWith ".md" (basename file)' | elem "myProjectFiles" (parents file)' -s ~/Documents
+```
+will show the same files - but now also including any files that are holdings (at any level) of the `myProjectFiles` folder - as a bash array.
 
+Run
+```
+$ tree-surgeon --help
+```
+to see a list of available commands.
 

src/app/Exceptions.hs

@@ -41,7 +41,7 @@ instance TextShow (FilterException a) where
         fromText $
             "Error: filter expression resolves to " <> expr
             <> " which is type " <> showt exprType
-            <> " but must be of type boolean"
+            <> " but must be of type Boolean"
     showb (DuplicateName _ name) =
         fromText $
             "Error: name " <> name
@@ -81,17 +81,18 @@ data OtherException =
 instance TextShow OtherException where
     showb (CanOnlyFilterDirectory fileName) =
         fromText $
-            "You have asked me to filter the file " <> fileName
-            <> " but I can only filter directories"
+            "You have asked me to filter the file: " <> fileName
+            <> ", but I can only filter directories"
     showb (Can'tParse) =
         fromText $
             "Unable to parse the filter string - did you forget to close a bracket or a list?"
     showb (FailedToReadTree name) =
         fromText $
-            "Could not read the following file: " <> name
+            "I could not read the requested source directory: " <> name
+            <> ", does it exist?"
 
 instance Show OtherException where
-    show e = show $ showb e
+    show e = T.unpack $ toText $ showb e
 
 instance Exception OtherException
 

src/app/Main.hs

@@ -20,7 +20,11 @@ main :: IO ()
 main = withUtf8 $ tsFilter =<< execParser opts
     where
         header' = "Tree surgeon: A utility for filtering and manipulating file trees"
-        progDesc' = "Use --help on a specific command to see more information"
+        progDesc' =
+            "Use --help to see a list of commands, or "
+            <> " COMMAND --help on a specific command to see more information; eg"
+            <> " tree-surgeon tree --help"
+            <> " to see help information on the tree command"
         fullDesc' = fullDesc <> header header' <> progDesc progDesc'
         opts = info
             (cliOptsParser <**> helper) fullDesc'

src/app/TreeFilter.hs

@@ -55,9 +55,10 @@ toElements' _ _ (Failed name err) = Failed name err
 
 applyFilter :: FileName -> BS.ByteString -> IO (Either [TSException X.Range] (DirTree FData))
 applyFilter dirname filterStr = do
-    anchoredTree <- readDirectoryWith return dirname
-    let validated = validateTree $ dirTree anchoredTree
-    let filtered = filterTreeWith filterStr =<< validated
+    (_ :/ tree) <- readDirectoryWith return dirname
+    let fDataTree = toElements tree
+    let validatedTree = validateTree dirname fDataTree
+    let filtered = filterTreeWith filterStr =<< validatedTree
     return filtered
 
 applyFilterWith :: FileName -> (DirTree FData -> IO()) -> BS.ByteString -> IO ()
@@ -100,13 +101,11 @@ getExcluded typeConstraint origTree filteredTree =
         arrayFiltered = toBashArray typeConstraint filteredTree
     in filter (\z -> not $ elem z arrayFiltered) arrayOrig
 
-filterTreeWith :: BS.ByteString -> DirTree a -> Either [TSException X.Range] (DirTree FData)
-filterTreeWith filterStr tree = do
+filterTreeWith :: BS.ByteString -> DirTree FData -> Either [TSException X.Range] (DirTree FData)
+filterTreeWith filterStr validatedTree = do
     simpleExp <- filterStrToSimpleExp filterStr
-    let tree' = toElements tree
-    validated <- validateTree tree'
     let matcher = applyExpression simpleExp
-    filtered <- filterTreeWith' [] matcher validated
+    filtered <- filterTreeWith' [] matcher validatedTree
     return $ fromJust filtered
 
 applyExpression :: IsTrace trc => SimpleExp trc -> FData -> EitherF trc Bool
@@ -115,12 +114,12 @@ applyExpression expr fData = do
     asBool <- convertToBool resolved
     return asBool
 
-validateTree :: DirTree a -> Either [TSException X.Range] (DirTree a)
-validateTree (File name _) = Left $ [Other $ CanOnlyFilterDirectory $ T.pack name]
-validateTree tree =
+validateTree :: FileName -> DirTree a -> Either [TSException X.Range] (DirTree a)
+validateTree dirName (File _ _) = Left $ [Other $ CanOnlyFilterDirectory $ T.pack dirName]
+validateTree dirName tree =
     case failures tree of
         [] -> Right tree
-        xs -> Left $ (\fl -> Other $ FailedToReadTree (T.pack $ name fl)) <$> xs
+        xs -> Left $ (\fl -> Other $ FailedToReadTree (T.pack $ dirName)) <$> xs
 
 filterTreeWith' ::
     [T.Text] -> Matcher a -> DirTree FData -> Either [TSException a] (Maybe (DirTree FData))