Externalize filters by using closures

closure_filters.groovy

/**
 * We have two functions with exactly the same code, but one has a filter, so I want to use the same code
 * but inject the filter by using a closure:
 */

// Filters
def filter_between = { min, max, n ->
   return min < n && n < max
}

def filter_null = {
   return true
}

// Function that uses the filter
boolean check( int n, Closure c )
{
   // other code
   if (c.call(n)) println "do something"
   // more code
}

// Calls
println check(100, filter_null) // execute without filter

println check(100, filter_between.curry(10).curry(500))  // 100 between 10 and 1500
println check(1000, filter_between.curry(10).curry(500)) // 1000 between 10 and 1500
println check(4, filter_between.curry(10).curry(500))    // 4 between 10 and 1500