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scalafor-loopfilterguard

Scala: Conditional guard in for loop

I need some enlightenment about the guard in a for loop in Scala: my code is

for {
  enterprise <- itr
  preferName <- enterprise \* qpreferedName
  variantName <- enterprise \* qvariantName
  attrVRes <- enterprise \* qtype \@ attrRes
  if (text(preferName).contains(keyword) || text(variantName).contains(keyword))
} {
//loop code
}

Now it works file. But I want to check the value of keyword, if it's an empty string, I will not apply this guard (if (text(preferName).contains(keyword) || text(variantName).contains(keyword))), otherwise apply it.

Can someone tell me a decent way to do it?

Solution

  • You can define such utility

    def textContains(str: String): String => Boolean = str match {
  case "" => Function.const(true)
  case _ => text(_).contains(str)
}

    and use it as 

    for {
 /* ... */
if Seq(preferName,variantName).exists(textContains(keyword))
} yield ???