extracting a tuple inside map function

[scott clasen]

What is the syntax to do the following? Also the REF("Option") business is not ideal I think.

t.map{

  case (k,v) => k -> Option(v)

}

REF("t") MAP LAMBDA(?How to get the case (k,v)?) ==> BLOCK(REF("k") ANY_-> REF("Option") APPLY REF("v"))

Ive got it working uglier like this 

t.map{ kv => kv._1 -> Option(kv._2) }

  REF("t") MAP LAMBDA(PARAM("kv")) ==> BLOCK(REF("kv._1") ANY_-> REF("Option") APPLY REF("kv._2"))

[eugene yokota]

Hi Scott,

The partial function literal is called "case sequence." See [1].

Option is already defined in definitions, but in general you can define symbols upfront.

import treehugger.forest._

import definitions._

import treehuggerDSL._

scala> val tree = REF("t") MAP BLOCK(

     |   CASE(TUPLE(ID("k"), ID("v"))) ==> (REF("k") ANY_-> (OptionClass APPLY REF("v")))

     | )

tree: treehugger.forest.Tree = Infix(Ident(t),map,List(Block(List(),CaseDef(Apply(Ident(Tuple2),List(Ident(k), Ident(v))),EmptyTree,Infix(Ident(k),->,List(Apply(Ident(Option),List(Ident(v)))))))))

scala> treeToString(tree)

res0: String = 

t map {

  case (k, v) => k -> Option(v)

}

-eugene

  [1]: http://eed3si9n.com/treehugger/caseseq.html

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[scott clasen]

Nice thanks!