Bracket Expression Beautifier

A simple beautifier for bracket expressions, implemented for, but not limited to, Scala ASTs.

Usage

General

scala> import com.github.mlangc.brackets.api._
scala> beautify("(2 * (3 + f(a, g(h(k(l(x) + 1) + 1) + 1) + 1)*5))")
res0: String =
(
  2 * (
    3 + f(
      a, g(
        h(k(l(x) + 1) + 1) + 1
      ) + 1
    )*5
  )
)
scala> import scala.reflect.runtime.universe._
scala> beautify(showRaw(reify { 3 + Seq(Seq(1, 2), Seq()).flatten.sum }))
res4: String =
Expr(
  Apply(
    Select(Literal(Constant(3)), TermName("$plus")), List(
      Apply(
        Select(
          Apply(
            Select(
              Apply(
                Select(Ident(scala.collection.Seq), TermName("apply")), List(
                  Apply(
                    Select(Ident(scala.collection.Seq), TermName("apply")), List(Literal(Constant(1)), Literal(Constant(2)))
                  ), Apply(Select(Ident(scala.collection.Seq), TermName("apply")), List())
                )
              ), TermName("flatten")
            ), List(Select(Ident(scala.Predef), TermName("$conforms")))
          ), TermName("sum")
        ), List(Select(Ident(scala.math.Numeric), TermName("IntIsIntegral")))
      )
    )
  )
)

If you want to add the beautifier as a dependency to your project, you can do so by add the following line to your build.sbt:

libraryDependencies += "com.github.mlangc" %% "bracket-expression-beautifier" % "2.0.0"

The library is available for Scala-2.11 and Scala-2.12.

For Quickly Dumping a few ASTs to the Console

Clone the repo, cd into it and run

$ sbt test:console

This starts an Ammonite-REPL with a few predefined imports. Use MetaAsts.format to print scala.meta ASTs and NscAsts.format to print ASTs from the Scala Compiler.

A sample session could look like

Welcome to the Ammonite Repl 0.8.2
@ MetaAsts.format(q"for(i <- 1.to(42)) yield i*i") 
res0: String = """
Term.ForYield(
  Seq(
    Enumerator.Generator(
      Pat.Var.Term(Term.Name("i")), Term.Apply(Term.Select(Lit(1), Term.Name("to")), Seq(Lit(42)))
    )
  ), Term.ApplyInfix(Term.Name("i"), Term.Name("*"), Nil, Seq(Term.Name("i")))
)
"""
@ NscAsts.format("for(i <- 1.to(42)) yield i*i") 
res1: String = """
Apply(
  Apply(
    TypeApply(
      Select(
        Apply(
          Select(
            Apply(
              Select(
                Select(This(TypeName("scala")), scala.Predef), TermName("intWrapper")
              ), List(Literal(Constant(1)))
            ), TermName("to")
          ), List(Literal(Constant(42)))
        ), TermName("map")
      ), List(TypeTree(), TypeTree())
    ), List(
      Function(
        List(ValDef(Modifiers(PARAM), TermName("i"), TypeTree(), EmptyTree)), Apply(
          Select(Ident(TermName("i")), TermName("$times")), List(Ident(TermName("i")))
        )
      )
    )
  ), List(
    TypeApply(
...