gistfile1.scala

import java.util.Date

/**
 * Usage:
 * 
 * val someFun: String = SimpleCache({ () => somethingExpensive }, 15.minutes).cachedFun
 * 
 * val theValue = someFun()
 */
class SimpleCache[T](
  fun: () => T,
  cacheTimeInMs: Long
) {

  private var lastUpdated: Date = new Date(0l)
  private var entry: Option[T] = None

  def cachedFun: () => T = {
    if (entry.isDefined &&
        (System.currentTimeMillis() - lastUpdated.getTime() < cacheTimeInMs)) {
      entry.get _
    } else {
      val result = fun()
      lastUpdated = new Date
      entry = Some(result)

      entry.get _
    }
  }
}