support.rb in flt-1.1.0

- old
+ new

@@ -481,13 +481,13 @@
             else
               if context.num_class == Float
                 float = true
                 context = BinNum::FloatContext
               end
-              x = context.num_class.context(context) do |context|
-                context.rounding = round_mode
-                Num.convert_exact(Num[eb].Num(sign, f, e), context.num_class, context)
+              x = context.num_class.context(context) do |loca_context|
+                local_context.rounding = round_mode
+                Num.convert_exact(Num[eb].Num(sign, f, e), local_context.num_class, local_context)
               end
               if float
                 x = x.to_f
               else
                 x = context.normalize(x) unless context.exact?
@@ -591,11 +591,11 @@
             e = Float::MIN_EXP
             e -= Float::MANT_DIG unless normalized
             min_exp = (e*Math.log(Float::RADIX)/Math.log(base)).ceil
             @float_min_max_exp_values[k] = min_max = [min_exp, max_exp]
           end
-          min_max.map{|e| e - 1} # adjust
+          min_max.map{|exp| exp - 1} # adjust
         end
       end
 
       def compare(m, x, y, context)
         ret = nil
@@ -1328,8 +1328,27 @@
     end # AuxiliarFunctions
 
   end # Support
 
 
+end # Flt
 
-
-end # Flt
\ No newline at end of file
+# The math method of context needs instance_exec to pass parameters to the blocks evaluated
+# with a modified self (pointing to a context object.) intance_exec is available in Ruby 1.9.1 and
+# is also defined by ActiveRecord. Here we use Mauricio Fernández implementation if it is not
+# available.
+class Object
+  unless defined? instance_exec
+    module InstanceExecHelper; end
+    include InstanceExecHelper
+    def instance_exec(*args, &block) # !> method redefined; discarding old instance_exec
+      mname = "__instance_exec_#{Thread.current.object_id.abs}_#{object_id.abs}"
+      InstanceExecHelper.module_eval{ define_method(mname, &block) }
+      begin
+        ret = send(mname, *args)
+      ensure
+        InstanceExecHelper.module_eval{ undef_method(mname) } rescue nil
+      end
+      ret
+    end
+  end
+end