Improve TypeError messages from failed array conversions.

Source/bindings/v8/ExceptionMessages.cpp

Index: Source/bindings/v8/ExceptionMessages.cpp
diff --git a/Source/bindings/v8/ExceptionMessages.cpp b/Source/bindings/v8/ExceptionMessages.cpp
index e1d879fe97f450f8c8da47fa431fbe2bdd4aeb59..d317e91021fda6e259da465d38d971cfca173033 100644
--- a/Source/bindings/v8/ExceptionMessages.cpp
+++ b/Source/bindings/v8/ExceptionMessages.cpp
@@ -58,9 +58,39 @@ String ExceptionMessages::failedToDelete(const String& property, const String& t
     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)