diff options
| -rw-r--r-- | src/dotty/tools/dotc/core/Decorators.scala | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/src/dotty/tools/dotc/core/Decorators.scala b/src/dotty/tools/dotc/core/Decorators.scala index af8704258..87473ca33 100644 --- a/src/dotty/tools/dotc/core/Decorators.scala +++ b/src/dotty/tools/dotc/core/Decorators.scala @@ -5,8 +5,10 @@ import annotation.tailrec import Symbols._ import Contexts._, Names._, Phases._ +/** This object provides useful implicit decorators for types defined elsewhere */ object Decorators { + /** Turns Strings into PreNames, adding toType/TermName methods */ implicit class StringDecorator(val s: String) extends AnyVal with PreName { def toTypeName: TypeName = typeName(s) def toTermName: TermName = termName(s) @@ -14,6 +16,9 @@ object Decorators { def toEncodedTermName = encodedTermName(s) } + /** Implements a findSymbol method on iterators of Symbols that + * works like find but avoids Option, replacing None with NoSymbol. + */ implicit class SymbolIteratorDecorator(val it: Iterator[Symbol]) extends AnyVal { final def findSymbol(p: Symbol => Boolean): Symbol = { while (it.hasNext) { @@ -24,14 +29,18 @@ object Decorators { } } - final val MaxRecursions = 1000 + final val MaxFilterRecursions = 1000 + /** Implements a filterConserve method on lists that avoids + * duplication of list nodes if all tests yield true. Works for lists + * up to `MaxFilterRecursions` length. + */ implicit class ListDecorator[T](val xs: List[T]) extends AnyVal { def filterConserve(p: T => Boolean): List[T] = { def loop(xs: List[T], nrec: Int): List[T] = xs match { case Nil => xs case x :: xs1 => - if (nrec < MaxRecursions) { + if (nrec < MaxFilterRecursions) { val ys1 = loop(xs1, nrec + 1) if (p(x)) if (ys1 eq xs1) xs else x :: ys1 @@ -43,6 +52,10 @@ object Decorators { } } + /** Implements a test whether a list of strings representing phases contains + * a given phase. The test returns true if the given phase starts with + * one of the names in the list of strings. + */ implicit class PhaseListDecorator(val names: List[String]) extends AnyVal { def containsPhase(phase: Phase) = names exists (phase.name.startsWith) |