Printable attribute improvements (#504)

* printeable -> printable

* Unify printable attribute checks and avoid unnecessary List construction

Author: cknitt

src/res_parens.ml

@@ -126,12 +126,8 @@ type kind = Parenthesized | Braced of Location.t | Nothing
             Pexp_lazy _
           | Pexp_assert _
         } when isLhs -> Parenthesized
-      | {Parsetree.pexp_attributes = (_::_) as attrs} ->
-        begin match ParsetreeViewer.filterPrinteableAttributes attrs with
-        | [] -> Nothing
-        | _ -> Parenthesized
-        end
-      | _ -> Nothing
+      | {Parsetree.pexp_attributes = attrs} ->
+        if ParsetreeViewer.hasPrintableAttributes attrs then Parenthesized else Nothing
       end
 
   let subBinaryExprOperand parentOperator childOperator =

src/res_parsetree_viewer.ml

@@ -451,17 +451,16 @@ let shouldInlineRhsBinaryExpr rhs = match rhs.pexp_desc with
   | Pexp_record _ -> true
   | _ -> false
 
-let filterPrinteableAttributes attrs =
-  List.filter (fun attr -> match attr with
+let isPrintableAttribute attr =
+  match attr with
     | ({Location.txt="bs" | "res.template" | "ns.ternary" | "ns.braces" | "ns.iflet" | "JSX"}, _) -> false
     | _ -> true
-  ) attrs
 
-let partitionPrinteableAttributes attrs =
-  List.partition (fun attr -> match attr with
-    | ({Location.txt="bs" | "res.template"| "ns.ternary" | "ns.iflet" | "JSX"}, _) -> false
-    | _ -> true
-  ) attrs
+let hasPrintableAttributes attrs = List.exists isPrintableAttribute attrs
+
+let filterPrintableAttributes attrs = List.filter isPrintableAttribute attrs
+
+let partitionPrintableAttributes attrs =  List.partition isPrintableAttribute attrs
 
 let requiresSpecialCallbackPrintingLastArg args =
   let rec loop args = match args with

src/res_parsetree_viewer.mli

@@ -81,8 +81,9 @@ val hasJsxAttribute: Parsetree.attributes -> bool
 
 val shouldIndentBinaryExpr: Parsetree.expression -> bool
 val shouldInlineRhsBinaryExpr: Parsetree.expression -> bool
-val filterPrinteableAttributes: Parsetree.attributes -> Parsetree.attributes
-val partitionPrinteableAttributes: Parsetree.attributes -> (Parsetree.attributes * Parsetree.attributes)
+val hasPrintableAttributes: Parsetree.attributes -> bool
+val filterPrintableAttributes: Parsetree.attributes -> Parsetree.attributes
+val partitionPrintableAttributes: Parsetree.attributes -> (Parsetree.attributes * Parsetree.attributes)
 
 val requiresSpecialCallbackPrintingLastArg: (Asttypes.arg_label * Parsetree.expression) list -> bool
 val requiresSpecialCallbackPrintingFirstArg: (Asttypes.arg_label * Parsetree.expression) list -> bool

src/res_printer.ml

@@ -3479,7 +3479,7 @@ and printBinaryExpression (expr : Parsetree.expression) cmtTbl =
             let leftPrinted = flatten ~isLhs:true left operator in
             let rightPrinted =
               let (_, rightAttrs) =
-                ParsetreeViewer.partitionPrinteableAttributes right.pexp_attributes
+                ParsetreeViewer.partitionPrintableAttributes right.pexp_attributes
               in
               let doc =
                 printExpressionWithComments
@@ -3491,11 +3491,11 @@ and printBinaryExpression (expr : Parsetree.expression) cmtTbl =
               else
                 doc
               in
-              let printeableAttrs =
-                ParsetreeViewer.filterPrinteableAttributes right.pexp_attributes
+              let printableAttrs =
+                ParsetreeViewer.filterPrintableAttributes right.pexp_attributes
               in
-              let doc = Doc.concat [printAttributes printeableAttrs cmtTbl; doc] in
-              match printeableAttrs with
+              let doc = Doc.concat [printAttributes printableAttrs cmtTbl; doc] in
+              match printableAttrs with
               | [] -> doc
               | _ -> addParens doc
             in