Make Uri._makeQuery easier to analyze

sdk/lib/core/uri.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart.core;
 
 /**
  * A parsed URI, such as a URL.
  *
  * **See also:**
@@ skipping 1364 matching lines @@
   static String _normalizePath(String path, String scheme, bool hasAuthority) {
     if (scheme.isEmpty && !hasAuthority && !path.startsWith('/')) {
       return _normalizeRelativePath(path);
     }
     return _removeDotSegments(path);
   }
 
   static String _makeQuery(
       String query, int start, int end,
       Map<String, dynamic/*String|Iterable<String>*/> queryParameters) {
-    if (query == null && queryParameters == null) return null;
     if (query != null && queryParameters != null) {
       throw new ArgumentError('Both query and queryParameters specified');
     }
     if (query != null) return _normalize(query, start, end, _queryCharTable);

[Lasse Reichstein Nielsen, 2016/08/17 10:53:12]

I hate seeing `if (query != null` twice.
How about:

if (query != null) {
  if (queryParameters == null) { 
    return _normalize(query, ...);
  }
  throw ...;
}
if (queryParameters == null) return null;
...

?

[sra1, 2016/08/17 17:41:35]

Done.

+    if (queryParameters == null) return null;
 
     var result = new StringBuffer();
     var separator = "";
 
     void writeParameter(String key, String value) {
       result.write(separator);
       separator = "&";
       result.write(Uri.encodeQueryComponent(key));
       if (value != null && value.isNotEmpty) {
         result.write("=");
@@ skipping 1952 matching lines @@
   // All non-escape RFC-2396 uric characters.
   //
   //  uric        =  reserved | unreserved | escaped
   //  reserved    =  ";" | "/" | "?" | ":" | "@" | "&" | "=" | "+" | "$" | ","
   //  unreserved  =  alphanum | mark
   //  mark        =  "-" | "_" | "." | "!" | "~" | "*" | "'" | "(" | ")"
   //
   // This is the same characters as in a URI query (which is URI pchar plus '?')
   static const _uricTable = Uri._queryCharTable;
 }