Improve TypeError messages from failed array conversions.

Source/bindings/v8/ExceptionMessages.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 40 matching lines @@
 String ExceptionMessages::failedToSet(const String& property, const String& type, const String& detail)
 {
     return "Failed to set the '" + property + "' property on '" + type + "': " + detail;
 }
 
 String ExceptionMessages::failedToDelete(const String& property, const String& type, const String& detail)
 {
     return "Failed to delete the '" + property + "' property from '" + type + "': " + detail;
 }
 
-String ExceptionMessages::notASequenceType(const String& argument)
+String ExceptionMessages::notASequenceType(int argumentIndex)
 {
-    return argument + " argument is neither an array, nor does it have indexed properties.";
+    String kind(" argument");
+
+    String prefix;
+    switch (argumentIndex) {
+    case 1:
+        prefix = "First";
+        break;
+    case 2:
+        prefix = "Second";
+        break;
+    case 3:
+        prefix = "Third";
+        break;
+    default:
+        if (argumentIndex <= 0)
+            kind = "Value";
+        else
+            prefix = String::number(argumentIndex) + "th";
+        break;
+    }

[Mike West, 2013/10/24 07:08:54]

I've avoided this in other places by phrasing it as "parameter X". I'm not sure
there's enough value in using words here to justify the (admittedly minimal)
complexity.

[sof, 2013/10/24 21:16:41]

I prefer "Second argument" (or "2nd argument") over "Argument 2"; I'm not sure
what you are advising here, but if you decide the suffix form is preferable
overall, I'll switch.

(Why "parameter" btw? Isn't it the "argument" that will be wrong/ill-typed?)

+    return prefix + kind + " is neither an array, nor does it have indexed properties.";
+}
+
+String ExceptionMessages::notASequenceType(const String& argument, const String& kind)
+{
+    String prefix;
+    if (kind.isEmpty())
+        prefix = argument + " argument";
+    else
+        prefix = "'" + argument + "' " + kind;
+    return prefix + " is neither an array, nor does it have indexed properties.";
 }
 
 String ExceptionMessages::notEnoughArguments(unsigned expected, unsigned provided)
 {
     return String::number(expected) + " argument" + (expected > 1 ? "s" : "") + " required, but only " + String::number(provided) + " present.";
 }
 
 } // namespace WebCore