Stop calling to_s on aliases, require them to be strings already.

lib/arel/alias_predication.rb

 module Arel
   module AliasPredication
     def as other
-      Nodes::As.new self, Nodes::SqlLiteral.new(other.to_s)
+      Nodes::As.new self, Nodes::SqlLiteral.new(other)
     end
   end
 end
\ No newline at end of file

lib/arel/nodes/function.rb

@@ -6,12 +6,12 @@ class Function < Arel::Nodes::Node
 
       def initialize expr, aliaz = nil
         @expressions = expr
-        @alias       = aliaz && SqlLiteral.new(aliaz.to_s)
+        @alias       = aliaz && SqlLiteral.new(aliaz)
         @distinct    = false
       end
 
       def as aliaz
-        self.alias = SqlLiteral.new(aliaz.to_s)
+        self.alias = SqlLiteral.new(aliaz)
         self
       end
     end

test/visitors/test_depth_first.rb

@@ -50,14 +50,14 @@ def test_raises_with_object
         Arel::Nodes::Sum,
       ].each do |klass|
         define_method("test_#{klass.name.gsub('::', '_')}") do
-          func = klass.new(:a, :b)
+          func = klass.new(:a, "b")
           @visitor.accept func
           assert_equal [:a, "b", false, func], @collector.calls
         end
       end
 
       def test_named_function
-        func = Arel::Nodes::NamedFunction.new(:a, :b, :c)
+        func = Arel::Nodes::NamedFunction.new(:a, :b, "c")
         @visitor.accept func
         assert_equal [:a, :b, false, "c", func], @collector.calls
       end
@@ -69,7 +69,7 @@ def test_lock
       end
 
       def test_count
-        count = Nodes::Count.new :a, :b, :c
+        count = Nodes::Count.new :a, :b, "c"
         @visitor.accept count
         assert_equal [:a, "c", :b, count], @collector.calls
       end

test/visitors/test_dot.rb

@@ -16,7 +16,7 @@ def setup
         Nodes::Avg,
       ].each do |klass|
         define_method("test_#{klass.name.gsub('::', '_')}") do
-          op = klass.new(:a, :z)
+          op = klass.new(:a, "z")
           @visitor.accept op
         end
       end