package com.sky.mattca.ccl3

/**
 * Created by Matt on 22/02/14.
 */
class SyntacticCategory(definition: SyntacticCategory*) {

  def this() {
    this()
  }

}

class OptionalSyntacticCategory(definition: SyntacticCategory*) extends SyntacticCategory(definition:_*) { }

class MultipleSyntacticCategory(definition: SyntacticCategory*) extends SyntacticCategory(definition:_*) { }

class OrSyntacticCategory(definition: SyntacticCategory*) extends SyntacticCategory(definition:_*) { }

class LiteralSyntacticCategory(definition: String) extends SyntacticCategory() { }

object SyntacticCategory {

  val Period = of(".")
  val Digit = of("1", "2", "3", "4", "5", "6", "7", "8", "9", "0")
  val UnaryMinus = of("-")

  val Integer = required(optional(UnaryMinus), Digit, multiple(Digit))
  val Decimal = required(optional(UnaryMinus), Digit, multiple(Digit), Period,
    Digit, multiple(Digit))

  def required(definition: SyntacticCategory*) = {
    new SyntacticCategory(definition:_*)
  }

  def optional(definition: SyntacticCategory*) = {
    new OptionalSyntacticCategory(definition:_*)
  }

  def multiple(definition: SyntacticCategory*) = {
    new MultipleSyntacticCategory(definition:_*)
  }

  def of(matches: String*) = {
    val literals = matches.map((literal) => {
      new LiteralSyntacticCategory(literal)
    })
    new OrSyntacticCategory(literals:_*)
  }

}