Perf blank lines (#918)

* Improve finding completely blank lines

* Inline type checks

* Don't check for trivia between attribute and binding if there are not attributes.

src/Fantomas/TokenParser.fs

@@ -465,20 +465,25 @@ let private findEmptyNewlinesInTokens (tokens: Token list) (lineCount) (ignoreRa
         |> Option.map (fun t -> t.LineNumber)
         |> Option.defaultValue lineCount
 
+    let ignoredLines =
+        ignoreRanges
+        |> List.collect(fun r -> [r.StartLine..r.EndLine])
+
+    let linesWithTokens =
+        tokens
+        |> List.groupBy (fun t -> t.LineNumber)
+
     let completeEmptyLines =
         [1 .. lastLineWithContent]
-        |> List.filter (fun line ->
-            not (List.exists (fun t -> t.LineNumber = line) tokens)
-                 && not (List.exists (fun (br:FSharp.Compiler.Range.range) -> br.StartLine < line && br.EndLine > line) ignoreRanges)
-        )
+        |> List.except (ignoredLines @ List.map fst linesWithTokens)
+        |> List.filter (fun line -> not (List.exists (fun t -> t.LineNumber = line) tokens))
         |> List.map createNewLine
 
     let linesWithOnlySpaces =
-        tokens
-        |> List.groupBy (fun t -> t.LineNumber)
+        linesWithTokens
         |> List.filter (fun (ln, g) -> ln <= lastLineWithContent && (List.length g) = 1 && (List.head g).TokenInfo.TokenName = "WHITESPACE")
         |> List.map (fst >> createNewLine)
-        
+
     completeEmptyLines @ linesWithOnlySpaces
 
 let getTriviaFromTokens (tokens: Token list) linesCount =

src/Fantomas/Trivia.fs

@@ -43,7 +43,7 @@ let private findFirstNodeOnLine (nodes: TriviaNode list) lineNumber : TriviaNode
     |> List.filter (fun { Range =r  } -> r.StartLine = lineNumber)
     |> List.tryHead
 
-let private mainNodeIs name (t:TriviaNodeAssigner) =
+let inline private mainNodeIs name (t:TriviaNodeAssigner) =
     match t.Type with
     | MainNode(mn) -> mn = name
     | _ -> false
@@ -54,7 +54,7 @@ let private nodesContainsBothAnonModuleAndOpen (nodes: TriviaNodeAssigner list)
 
 // the member keyword is not part of an AST node range
 // so it is not an ideal candidate node to have trivia content
-let private isNotMemberKeyword (node: TriviaNodeAssigner) =
+let inline private isNotMemberKeyword (node: TriviaNodeAssigner) =
     match node.Type with
     | Token({ TokenInfo = ti }) when (ti.TokenName = "MEMBER") -> false
     | _ -> true
@@ -232,7 +232,7 @@ let private findASTNodeOfTypeThatContains (nodes: TriviaNodeAssigner list) typeN
         | _ -> false)
     |> List.tryHead
 
-let private addTriviaToTriviaNode (startOfSourceCode:int) (triviaNodes: TriviaNodeAssigner list) trivia =
+let private addTriviaToTriviaNode triviaBetweenAttributeAndParentBinding (startOfSourceCode:int) (triviaNodes: TriviaNodeAssigner list) trivia =
     match trivia with
     | { Item = Comment(LineCommentOnSingleLine(_)) as comment; Range = range } when (commentIsAfterLastTriviaNode triviaNodes range) ->
         // Comment on is on its own line after all Trivia nodes, most likely at the end of a module
@@ -381,8 +381,10 @@ let collectTrivia tokens lineCount (ast: ParsedInput) =
     let triviaNodesFromAST =
         flattenNodeToList node
         |> filterNodes
-        |> List.map mapNodeToTriviaNode
-        |> List.choose id
+        |> List.choose mapNodeToTriviaNode
+
+    let hasAnyAttributes = List.exists (fun (tn:TriviaNodeAssigner) -> match tn.Type with | MainNode("SynAttributeList") -> true | _ -> false) triviaNodesFromAST
+    let triviaBetweenAttributeAndParentBinding = if hasAnyAttributes then triviaBetweenAttributeAndParentBinding else (fun _ _ -> None)
     let triviaNodesFromTokens = TokenParser.getTriviaNodesFromTokens tokens
     let triviaNodes = triviaNodesFromAST @ triviaNodesFromTokens |> List.sortBy (fun n -> n.Range.Start.Line, n.Range.Start.Column)
 
@@ -391,7 +393,7 @@ let collectTrivia tokens lineCount (ast: ParsedInput) =
     match trivias with
     | [] -> []
     | _ ->
-        List.fold (addTriviaToTriviaNode startOfSourceCode) triviaNodes trivias
+        List.fold (addTriviaToTriviaNode triviaBetweenAttributeAndParentBinding startOfSourceCode) triviaNodes trivias
         |> List.choose (fun tn ->
             if triviaNodeIsNotEmpty tn then
                 { Type = tn.Type