Scala - omit parentheses from apply method for a DSL -

i'm trying create dsl , running problem. have these definitions:

case class var(name: string) case class lam(v: var, t: var) val (a, b) = (var("a"), var("b")) 

i want able this:

scala> \ b lam(var(a),var(b)) 

reading on rules of parenthesis dropping, see need chain functions take 1 parameter each, i've created series of "builder" classes perform construction:

class lambuilderb(v: var) {     def apply(t: var) = lam(v, t) }  class lambuildera {     def apply(v: var) = new lambuilderb(v) }  val \ = new lambuildera 

i had hoped work since each apply takes 1 argument. but, doesn't seem dropping parentheses legal apply since wants treat argument method name:

scala> \(a)(b) res95: lam = lam(var(a),var(b))  scala> \ b error: value not member of lambuildera     \ b       ^ 

any ideas how how can dsl syntax without parentheses?

bonus question: can this?:

scala> \a.b lam(var(a),var(b)) 

you can pretty close using 1 of 4 unary prefix operators (~, !, +, -):

trait expr {     def &(other: expr) = lam(this, other)     def unary_~ = }  case class var(name: string) extends expr case class lam(a: expr, b: expr) extends expr  scala> ~ var("a") & var("b") res0: lam = lam(var(a),var(b))  scala> ~ var("a") & var("b") & var("c") res1: lam = lam(lam(var(a),var(b)),var(c))