ReDuxml brings XML to life by allowing users to parameterize content using a simple syntax requiring no more than middle-school-level math to make design data captured by XML dynamic. The resulting designs can then be used to generate further designs by setting parameter values and running #resolve. Content reuse within complex designs can multiply, vastly reducing the size and complexity of projects. To illustrate:

require 're_duxml'
include ReDuxml

load 'file.xml'
doc.to_s           => '<root>
                        <parameters><parameter name="foo" value="10"/></parameters>
                        <should if="@(foo == 10")>i stay or</should>
                        <should if="@(foo == 9)">i go now?</should></root>'
resolve doc         => '<root>
                       <should>i stay or</should>
                       </root>'
doc.parameters[:foo] = 9
  => #<ReDuxml::ParameterClass>
resolve doc         => '<root>
                        <should>i go now</should
                        </root>

You can also create an Evaluator object that can evaluate parameterized strings, i.e. Macro objects, using operator properties from three sources, in order:

• logic.xml
• Symbolic gem
• Ruby

So a simple logical expression involving basic arithmetic can include unknown values and still be evaluated, e.g:

e = Evaluator.new('logic.xml')           => #<Evaluator>
e.evaluate('(2x - x) < y')               => 'x < y'
e.evaluate('(2x - x) < y', {y: x})       => false
e.evaluate('(2x - x) < y', {x: 0, y: 1}) => true