GenerateStaticSignalCombineOps.scala

import sbt._

import java.io.File

case class GenerateStaticSignalCombineOps(
  sourceDir: File,
  from: Int,
  to: Int
) extends SourceGenerator(
  sourceDir / "scala" / "com" / "raquo" / "airstream" / "combine" / "generated" / s"StaticSignalCombineOps.scala"
) {

  override def apply(): Unit = {
    line("package com.raquo.airstream.combine.generated")
    line()
    line("import com.raquo.airstream.combine.CombineSignalN")
    line("import com.raquo.airstream.core.Signal")
    line("import com.raquo.airstream.core.Source.SignalSource")
    line("import com.raquo.ew.JsArray")
    line()
    line("// #Warning do not edit this file directly, it is generated by GenerateStaticSignalCombineOps.scala")
    line()
    line("// These combine and combineWith methods are available on the Signal companion object")
    line("// For instance methods of the same name, see CombinableSignal.scala")
    line()
    enter(s"object StaticSignalCombineOps {", "}") {
      line()
      for (n <- from to to) {
        enter(s"def combine[${tupleType(n)}](") {
          line((1 to n).map(i => s"s${i}: SignalSource[T${i}]").mkString(", "))
        }
        enter(s"): Signal[(${tupleType(n)})] = {", "}") {
          line(s"combineWithFn(${tupleType(n, "s")})(Tuple${n}.apply[${tupleType(n)}])")
        }
        line()
        line("/** @param combinator Must not throw! */")
        enter(s"def combineWithFn[${tupleType(n)}, Out](") {
          line((1 to n).map(i => s"s${i}: SignalSource[T${i}]").mkString(", "))
        }
        enter(")(") {
          line(s"combinator: (${tupleType(n)}) => Out")
        }
        enter(s"): Signal[Out] = {", "}") {
          // line(s"val parents = JsArray(${tupleType(n, "s", ".toObservable")})")
          // line(s"val arrCombinator = (arr: JsArray[Any]) => combinator(${(0 until n).map(i => s"arr(${i}).asInstanceOf[T${i + 1}]").mkString(", ")})")
          // enter("new CombineSignalN(", ")") {
          //   line("parents, arrCombinator")
          // }
          enter("new CombineSignalN[Any, Out](", ")") {
            line(s"parents = JsArray(${tupleType(n, "s", ".toObservable")}),")
            enter(s"combinator = arr => combinator(", ")") {
              for (i <- 0 until n) {
                line(s"arr(${i}).asInstanceOf[T${i+1}],")
              }
            }
          }
        }
        line()
        line("// --")
        line()
      }
    }
  }

}