Better way to check if a pattern is matching (not regex)

Question

I want to a pattern is matching or not.

I end up writing a horrid piece of code like this

val isMatch = something match { 
    case Some(Complex(Pattern(matching) :: Nil)) => true
    case _ => false
}

This looks to me exactly like doing this

val isConditionTrue = if (someCondition) {
  true 
} else { 
  false 
}

Which is an eye sore and can be reduced of course to this

val isConditionTrue = someCondition

Or simply

someCondition

But I couldn't find a way (perhaps I'm missing something silly) to do that with a pattern matching (again, not talking about Regex here, just good old Scala pattern matching

Is there something to do here with a Partial Function / isDefinedAt etc? Is there any utility method to check e.g. something like

isPatternMatching(object, Pattern)

make your own function – Bhojendra Rauniyar Apr 09 '14 at 03:05 — Bhojendra Rauniyar, Apr 09 '14 at 03:05

score 2 · Accepted Answer · edited May 23 '17 at 12:13

2

There's an answer where @extempore complains that no one ever offers this as an answer:

scala> import PartialFunction._
import PartialFunction._

scala> cond(Some(1)) { case Some(i) if i > 0 => true }
res0: Boolean = true

Update:

It was actually easy to find, because it's his top-rated answer.

https://stackoverflow.com/a/4442273/1296806

This was the source for the "impressively obscure" hoodie in the Scala store.

edited May 23 '17 at 12:13

Community

1
1

answered Apr 09 '14 at 03:25

som-snytt

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Exactly what I wanted. I wonder if I could just check isDefinedAt and then do `=> _` – Eran Medan Apr 09 '14 at 03:41

Better way to check if a pattern is matching (not regex)

1 Answers1