groovy enum fun

mpciEnumPatchapplStrategies.groovy

enum mpciEnumPatchapplStrategies {
  MERGE("merge", "mrg"),
  ADDDIFF("addDiff"),
  BOGUS();

  final static def addDiff = ADDDIFF, merge = MERGE, adddiff = ADDDIFF;

  static {
    def oldAsType = String.metaClass.getMetaMethod("asType", [Class] as Class[])
    String.metaClass.asType = { Class type ->
        type.isAssignableFrom(mpciEnumPatchapplStrategies) ?
            mpciEnumPatchapplStrategies.fromString(delegate) :
            oldAsType.invoke(delegate, [type] as Class[])
    }
  }

  final Set<String> aliases;
  //final String value;

  mpciEnumPatchapplStrategies(String... v) {
    this.aliases = v;
  }

  //mpciEnumPatchapplStrategies(String v) {
  //  this.value = v;
  //}

  static {
    mpciEnumPatchapplStrategies.metaClass.mpciEnumPatchapplStrategies = { def s ->
      if (s instanceof mpciEnumPatchapplStrategies)
        return s
      if (s instanceof String)
        return mpciEnumPatchapplStrategies.fromString(s)
      return null
    }
  }

  static valuesString() {
    values().collect {it.toString() + " (${it.name()})"}
  }

  static fromString(String v) {
    return values().find {(v in it.aliases || it.name().equals(v))} ?: null
  }

  String toString() {
    this.aliases[0] ?: this.name()
  }
}

println GroovySystem.version

for (v in mpciEnumPatchapplStrategies.valuesString()) {
  println "${v.class}: '${v}'"
}

println "=== s1"
def s1 = mpciEnumPatchapplStrategies.adddiff
println s1

println "=== s2"
def s2 = mpciEnumPatchapplStrategies.ADDDIFF
println s2

println "=== s3"
mpciEnumPatchapplStrategies s3 = mpciEnumPatchapplStrategies.ADDDIFF
println s3

println "=== s4"
mpciEnumPatchapplStrategies s4 = 'ADDDIFF'
println s4

println "=== s5"
mpciEnumPatchapplStrategies s5 = 'addDiff' as mpciEnumPatchapplStrategies
println s5

println "=== s6"
mpciEnumPatchapplStrategies s6 = 'ADDDIFF' as mpciEnumPatchapplStrategies
println s6

println "=== s7"
def s7 = 'ADDDIFF' as mpciEnumPatchapplStrategies
println s7

println "=== s8"
def s8 = 'addDiff' as mpciEnumPatchapplStrategies
println s8

println "=== s9 (adddiff => null - no such alias)"
def s9 = 'adddiff' as mpciEnumPatchapplStrategies
println s9

println "=== s10 (mrg => merge)"
def s10 = 'mrg' as mpciEnumPatchapplStrategies
println s10

println "=== s11 (addDiff)"
def s11 = mpciEnumPatchapplStrategies.fromString('addDiff')
println s11


println "=== s11 again (bogus DEF should not fail?)"
s11 = 'chew'
println s11

// should crash
println "=== s6 again (bogus ENUM type should fail)"
s6 = 'chew'
println s6