dotty.tools.dotc.printing.PlainPrinter.scala Maven / Gradle / Ivy
package dotty.tools.dotc
package printing
import core._
import Texts._, Types._, Flags._, Names._, Symbols._, NameOps._, Constants._, Denotations._
import Contexts.Context, Scopes.Scope, Denotations.Denotation, Annotations.Annotation
import StdNames.{nme, tpnme}
import ast.Trees._, ast._
import typer.Implicits._
import typer.ImportInfo
import config.Config
import java.lang.Integer.toOctalString
import config.Config.summarizeDepth
import scala.util.control.NonFatal
import scala.annotation.switch
class PlainPrinter(_ctx: Context) extends Printer {
protected[this] implicit def ctx: Context = _ctx.addMode(Mode.Printing)
private[this] var openRecs: List[RecType] = Nil
protected def maxToTextRecursions = 100
protected final def controlled(op: => Text): Text =
if (ctx.toTextRecursions < maxToTextRecursions && ctx.toTextRecursions < maxSummarized)
try {
ctx.toTextRecursions += 1
op
} finally {
ctx.toTextRecursions -= 1
}
else {
if (ctx.toTextRecursions >= maxToTextRecursions)
recursionLimitExceeded()
"..."
}
protected def recursionLimitExceeded() = {
ctx.warning("Exceeded recursion depth attempting to print.")
if (ctx.debug) Thread.dumpStack()
}
/** If true, tweak output so it is the same before and after pickling */
protected def homogenizedView: Boolean = ctx.settings.YtestPickler.value
def homogenize(tp: Type): Type =
if (homogenizedView)
tp match {
case tp: ThisType if tp.cls.is(Package) && !tp.cls.isEffectiveRoot =>
ctx.requiredPackage(tp.cls.fullName).termRef
case tp: TypeVar if tp.isInstantiated =>
homogenize(tp.instanceOpt)
case AndType(tp1, tp2) =>
homogenize(tp1) & homogenize(tp2)
case OrType(tp1, tp2) =>
homogenize(tp1) | homogenize(tp2)
case tp: SkolemType =>
homogenize(tp.info)
case tp: LazyRef =>
homogenize(tp.ref)
case AppliedType(tycon, args) =>
tycon.dealias.appliedTo(args)
case _ =>
tp
}
else tp
private def sameBound(lo: Type, hi: Type): Boolean =
try ctx.typeComparer.isSameTypeWhenFrozen(lo, hi)
catch { case NonFatal(ex) => false }
private def homogenizeArg(tp: Type) = tp match {
case TypeBounds(lo, hi) if homogenizedView && sameBound(lo, hi) => homogenize(hi)
case _ => tp
}
private def selfRecName(n: Int) = s"z$n"
/** If the name of the symbol's owner should be used when you care about
* seeing an interesting name: in such cases this symbol is e.g. a method
* parameter with a synthetic name, a constructor named "this", an object
* "package", etc. The kind string, if non-empty, will be phrased relative
* to the name of the owner.
*/
protected def hasMeaninglessName(sym: Symbol) = (
(sym is Param) && sym.owner.isSetter // x$1
|| sym.isClassConstructor // this
|| (sym.name == nme.PACKAGE) // package
)
def nameString(name: Name): String = name.toString
def toText(name: Name): Text = Str(nameString(name))
/** String representation of a name used in a refinement
* In refined printing this undoes type parameter expansion
*/
protected def refinementNameString(tp: RefinedType) = nameString(tp.refinedName)
/** String representation of a refinement */
protected def toTextRefinement(rt: RefinedType) =
(refinementNameString(rt) ~ toTextRHS(rt.refinedInfo)).close
protected def argText(arg: Type): Text = homogenizeArg(arg) match {
case arg: TypeBounds => "_" ~ toTextGlobal(arg)
case arg => toTextGlobal(arg)
}
/** The longest sequence of refinement types, starting at given type
* and following parents.
*/
private def refinementChain(tp: Type): List[Type] =
tp :: (tp match {
case tp: RefinedType => refinementChain(tp.parent.stripTypeVar)
case _ => Nil
})
/** Direct references to these symbols are printed without their prefix for convenience.
* They are either aliased in scala.Predef or in the scala package object.
*/
private[this] lazy val printWithoutPrefix: Set[Symbol] =
(defn.ScalaPredefModuleRef.typeAliasMembers
++ defn.ScalaPackageObjectRef.typeAliasMembers).map(_.info.classSymbol).toSet
def toText(tp: Type): Text = controlled {
homogenize(tp) match {
case tp: TypeType =>
toTextRHS(tp)
case tp: TermRef
if !tp.denotationIsCurrent && !homogenizedView || // always print underlying when testing picklers
tp.symbol.is(Module) || tp.symbol.name == nme.IMPORT =>
toTextRef(tp) ~ ".type"
case tp: TermRef if tp.denot.isOverloaded =>
""
case tp: TypeRef =>
if (printWithoutPrefix.contains(tp.symbol))
toText(tp.name)
else
toTextPrefix(tp.prefix) ~ selectionString(tp)
case tp: TermParamRef =>
ParamRefNameString(tp) ~ ".type"
case tp: TypeParamRef =>
ParamRefNameString(tp) ~ lambdaHash(tp.binder)
case tp: SingletonType =>
toTextLocal(tp.underlying) ~ "(" ~ toTextRef(tp) ~ ")"
case AppliedType(tycon, args) =>
(toTextLocal(tycon) ~ "[" ~ Text(args map argText, ", ") ~ "]").close
case tp: RefinedType =>
val parent :: (refined: List[RefinedType @unchecked]) =
refinementChain(tp).reverse
toTextLocal(parent) ~ "{" ~ Text(refined map toTextRefinement, "; ").close ~ "}"
case tp: RecType =>
try {
openRecs = tp :: openRecs
"{" ~ selfRecName(openRecs.length) ~ " => " ~ toTextGlobal(tp.parent) ~ "}"
}
finally openRecs = openRecs.tail
case AndType(tp1, tp2) =>
changePrec(AndPrec) { toText(tp1) ~ " & " ~ toText(tp2) }
case OrType(tp1, tp2) =>
changePrec(OrPrec) { toText(tp1) ~ " | " ~ toText(tp2) }
case tp: ErrorType =>
s""
case tp: WildcardType =>
if (tp.optBounds.exists) "(?" ~ toTextRHS(tp.bounds) ~ ")" else "?"
case NoType =>
""
case NoPrefix =>
""
case tp: MethodType =>
changePrec(GlobalPrec) {
("(" + (if (tp.isErasedMethod) "erased " else "")
+ (if (tp.isImplicitMethod) "implicit " else "")
) ~ paramsText(tp) ~
(if (tp.resultType.isInstanceOf[MethodType]) ")" else "): ") ~
toText(tp.resultType)
}
case tp: ExprType =>
changePrec(GlobalPrec) { "=> " ~ toText(tp.resultType) }
case tp: TypeLambda =>
changePrec(GlobalPrec) {
"[" ~ paramsText(tp) ~ "]" ~ lambdaHash(tp) ~
(Str(" => ") provided !tp.resultType.isInstanceOf[MethodType]) ~
toTextGlobal(tp.resultType)
}
case AnnotatedType(tpe, annot) =>
toTextLocal(tpe) ~ " " ~ toText(annot)
case tp: TypeVar =>
if (tp.isInstantiated)
toTextLocal(tp.instanceOpt) ~ (Str("^") provided ctx.settings.YprintDebug.value)
else {
val constr = ctx.typerState.constraint
val bounds =
if (constr.contains(tp)) constr.fullBounds(tp.origin)(ctx.addMode(Mode.Printing))
else TypeBounds.empty
if (bounds.isAlias) toText(bounds.lo) ~ (Str("^") provided ctx.settings.YprintDebug.value)
else if (ctx.settings.YshowVarBounds.value) "(" ~ toText(tp.origin) ~ "?" ~ toText(bounds) ~ ")"
else toText(tp.origin)
}
case tp: LazyRef =>
def refTxt =
try toTextGlobal(tp.ref)
catch {
case ex: Throwable => Str("...")
}
"LazyRef(" ~ refTxt ~ ")"
case _ =>
tp.fallbackToText(this)
}
}.close
protected def paramsText(tp: LambdaType): Text = {
def paramText(name: Name, tp: Type) = toText(name) ~ toTextRHS(tp)
Text((tp.paramNames, tp.paramInfos).zipped.map(paramText), ", ")
}
protected def ParamRefNameString(name: Name): String = name.toString
protected def ParamRefNameString(param: ParamRef): String =
ParamRefNameString(param.binder.paramNames(param.paramNum))
/** The name of the symbol without a unique id. */
protected def simpleNameString(sym: Symbol): String = nameString(sym.name)
/** If -uniqid is set, the hashcode of the lambda type, after a # */
protected def lambdaHash(pt: LambdaType): Text =
if (ctx.settings.uniqid.value)
try "#" + pt.hashCode
catch { case ex: NullPointerException => "" }
else ""
/** If -uniqid is set, the unique id of symbol, after a # */
protected def idString(sym: Symbol): String =
if (ctx.settings.uniqid.value || Printer.debugPrintUnique) "#" + sym.id else ""
def nameString(sym: Symbol): String =
simpleNameString(sym) + idString(sym) // + "<" + (if (sym.exists) sym.owner else "") + ">"
def fullNameString(sym: Symbol): String =
if (sym.isRoot || sym == NoSymbol || sym.owner.isEffectiveRoot)
nameString(sym)
else
fullNameString(fullNameOwner(sym)) + "." + nameString(sym)
protected def fullNameOwner(sym: Symbol): Symbol = sym.effectiveOwner.enclosingClass
protected def objectPrefix = "object "
protected def packagePrefix = "package "
protected def trimPrefix(text: Text) =
text.stripPrefix(objectPrefix).stripPrefix(packagePrefix)
protected def selectionString(tp: NamedType) = {
val sym = if (homogenizedView) tp.symbol else tp.currentSymbol
if (sym.exists) nameString(sym) else nameString(tp.name)
}
/** The string representation of this type used as a prefix */
protected def toTextRef(tp: SingletonType): Text = controlled {
tp match {
case tp: TermRef =>
toTextPrefix(tp.prefix) ~ selectionString(tp)
case tp: ThisType =>
nameString(tp.cls) + ".this"
case SuperType(thistpe: SingletonType, _) =>
toTextRef(thistpe).map(_.replaceAll("""\bthis$""", "super"))
case SuperType(thistpe, _) =>
"Super(" ~ toTextGlobal(thistpe) ~ ")"
case tp @ ConstantType(value) =>
toText(value)
case pref: TermParamRef =>
nameString(pref.binder.paramNames(pref.paramNum))
case tp: RecThis =>
val idx = openRecs.reverse.indexOf(tp.binder)
if (idx >= 0) selfRecName(idx + 1)
else "{...}.this" // TODO move underlying type to an addendum, e.g. ... z3 ... where z3: ...
case tp: SkolemType =>
if (homogenizedView) toText(tp.info) else toText(tp.repr)
}
}
/** The string representation of this type used as a prefix */
protected def toTextPrefix(tp: Type): Text = controlled {
homogenize(tp) match {
case NoPrefix => ""
case tp: SingletonType => toTextRef(tp) ~ "."
case tp => trimPrefix(toTextLocal(tp)) ~ "#"
}
}
protected def isOmittablePrefix(sym: Symbol): Boolean =
defn.UnqualifiedOwnerTypes.exists(_.symbol == sym) || isEmptyPrefix(sym)
protected def isEmptyPrefix(sym: Symbol): Boolean =
sym.isEffectiveRoot || sym.isAnonymousClass || sym.name.isReplWrapperName
/** String representation of a definition's type following its name,
* if symbol is completed, "?" otherwise.
*/
protected def toTextRHS(optType: Option[Type]): Text = optType match {
case Some(tp) => toTextRHS(tp)
case None => "?"
}
/** String representation of a definition's type following its name */
protected def toTextRHS(tp: Type): Text = controlled {
homogenize(tp) match {
case tp: TypeAlias =>
" = " ~ toText(tp.alias)
case tp @ TypeBounds(lo, hi) =>
(if (lo isRef defn.NothingClass) Text() else " >: " ~ toText(lo)) ~
(if (hi isRef defn.AnyClass) Text() else " <: " ~ toText(hi))
case tp @ ClassInfo(pre, cls, cparents, decls, selfInfo) =>
val preText = toTextLocal(pre)
val (tparams, otherDecls) = decls.toList partition treatAsTypeParam
val tparamsText =
if (tparams.isEmpty) Text() else ("[" ~ dclsText(tparams) ~ "]").close
val selfText: Text = selfInfo match {
case NoType => Text()
case sym: Symbol if !sym.isCompleted => "this: ? =>"
case _ => "this: " ~ atPrec(InfixPrec) { toText(tp.selfType) } ~ " =>"
}
val trueDecls = otherDecls.filterNot(treatAsTypeArg)
val declsText =
if (trueDecls.isEmpty || !ctx.settings.Ydebug.value) Text()
else dclsText(trueDecls)
tparamsText ~ " extends " ~ toTextParents(tp.parents) ~ "{" ~ selfText ~ declsText ~
"} at " ~ preText
case mt: MethodType =>
toTextGlobal(mt)
case tp: ExprType =>
": => " ~ toTextGlobal(tp.widenExpr)
case tp =>
": " ~ toTextGlobal(tp)
}
}
protected def toTextParents(parents: List[Type]): Text = Text(parents.map(toTextLocal), " with ")
protected def treatAsTypeParam(sym: Symbol): Boolean = false
protected def treatAsTypeArg(sym: Symbol): Boolean = false
/** String representation of symbol's kind. */
def kindString(sym: Symbol): String = {
val flags = sym.flagsUNSAFE
if (flags is PackageClass) "package class"
else if (flags is PackageVal) "package"
else if (sym.isPackageObject)
if (sym.isClass) "package object class"
else "package object"
else if (sym.isAnonymousClass) "anonymous class"
else if (flags is ModuleClass) "module class"
else if (flags is ModuleVal) "module"
else if (flags is ImplClass) "implementation class"
else if (flags is Trait) "trait"
else if (sym.isClass) "class"
else if (sym.isType) "type"
else if (sym.isGetter) "getter"
else if (sym.isSetter) "setter"
else if (flags is Lazy) "lazy value"
else if (flags is Mutable) "variable"
else if (sym.isClassConstructor && sym.isPrimaryConstructor) "primary constructor"
else if (sym.isClassConstructor) "constructor"
else if (sym.is(Method)) "method"
else if (sym.isTerm) "value"
else ""
}
/** String representation of symbol's definition key word */
protected def keyString(sym: Symbol): String = {
val flags = sym.flagsUNSAFE
if (flags is JavaTrait) "interface"
else if (flags is Trait) "trait"
else if (sym.isClass) "class"
else if (sym.isType) "type"
else if (flags is Mutable) "var"
else if (flags is Package) "package"
else if (flags is Module) "object"
else if (sym is Method) "def"
else if (sym.isTerm && (!(flags is Param))) "val"
else ""
}
/** String representation of symbol's flags */
protected def toTextFlags(sym: Symbol): Text =
Text(sym.flagsUNSAFE.flagStrings map stringToText, " ")
/** String representation of symbol's variance or "" if not applicable */
protected def varianceString(sym: Symbol): String = varianceString(sym.variance)
protected def varianceString(v: Int): String = v match {
case -1 => "-"
case 1 => "+"
case _ => ""
}
def annotsText(sym: Symbol): Text = Text(sym.annotations.map(toText))
def dclText(sym: Symbol): Text = dclTextWithInfo(sym, sym.unforcedInfo)
def dclText(d: SingleDenotation): Text = dclTextWithInfo(d.symbol, Some(d.info))
private def dclTextWithInfo(sym: Symbol, info: Option[Type]): Text =
(toTextFlags(sym) ~~ keyString(sym) ~~
(varianceString(sym) ~ nameString(sym)) ~ toTextRHS(info)).close
def toText(sym: Symbol): Text =
(kindString(sym) ~~ {
if (sym.isAnonymousClass) toText(sym.info.parents, " with ") ~ "{...}"
else if (hasMeaninglessName(sym)) simpleNameString(sym.owner) + idString(sym)
else nameString(sym)
}).close
def locationText(sym: Symbol): Text =
if (!sym.exists) ""
else {
val ownr = sym.effectiveOwner
if (ownr.isClass && !isEmptyPrefix(ownr)) " in " ~ toText(ownr) else Text()
}
def locatedText(sym: Symbol): Text =
(toText(sym) ~ locationText(sym)).close
def extendedLocationText(sym: Symbol): Text =
if (!sym.exists) ""
else {
def recur(ownr: Symbol, innerLocation: String): Text = {
def nextOuter(innerKind: String): Text =
recur(ownr.effectiveOwner,
if (!innerLocation.isEmpty) innerLocation
else s" in an anonymous $innerKind")
def showLocation(ownr: Symbol, where: String): Text =
innerLocation ~ " " ~ where ~ " " ~ toText(ownr)
if (ownr.isAnonymousClass) nextOuter("class")
else if (ownr.isAnonymousFunction) nextOuter("function")
else if (isEmptyPrefix(ownr)) ""
else if (ownr.isLocalDummy) showLocation(ownr.owner, "locally defined in")
else if (ownr.isTerm && !ownr.is(Module | Method)) showLocation(ownr, "in the initalizer of")
else showLocation(ownr, "in")
}
recur(sym.owner, "")
}
def toText(denot: Denotation): Text = toText(denot.symbol) ~ "/D"
private def escapedChar(ch: Char): String = (ch: @switch) match {
case '\b' => "\\b"
case '\t' => "\\t"
case '\n' => "\\n"
case '\f' => "\\f"
case '\r' => "\\r"
case '"' => "\\\""
case '\'' => "\\\'"
case '\\' => "\\\\"
case _ => if (ch.isControl) "\\0" + toOctalString(ch) else String.valueOf(ch)
}
def toText(const: Constant): Text = const.tag match {
case StringTag => stringText("\"" + escapedString(const.value.toString) + "\"")
case ClazzTag => "classOf[" ~ toText(const.typeValue.classSymbol) ~ "]"
case CharTag => literalText(s"'${escapedChar(const.charValue)}'")
case LongTag => literalText(const.longValue.toString + "L")
case EnumTag => literalText(const.symbolValue.name.toString)
case ScalaSymbolTag => literalText("'" + const.scalaSymbolValue.name.toString)
case _ => literalText(String.valueOf(const.value))
}
def toText(annot: Annotation): Text = s"@${annot.symbol.name}" // for now
protected def escapedString(str: String): String = str flatMap escapedChar
def dclsText(syms: List[Symbol], sep: String): Text = Text(syms map dclText, sep)
def toText(sc: Scope): Text =
("Scope{" ~ dclsText(sc.toList) ~ "}").close
def toText[T >: Untyped](tree: Tree[T]): Text = {
def toTextElem(elem: Any): Text = elem match {
case elem: Showable => elem.toText(this)
case elem: List[_] => "List(" ~ Text(elem map toTextElem, ",") ~ ")"
case elem => elem.toString
}
val nodeName = tree.productPrefix
val elems =
Text(tree.productIterator.map(toTextElem).toList, ", ")
val tpSuffix =
if (ctx.settings.XprintTypes.value && tree.hasType)
" | " ~ toText(tree.typeOpt)
else
Text()
nodeName ~ "(" ~ elems ~ tpSuffix ~ ")" ~ (Str(tree.pos.toString) provided ctx.settings.YprintPos.value)
}.close // todo: override in refined printer
def toText(result: SearchResult): Text = result match {
case result: SearchSuccess =>
"SearchSuccess: " ~ toText(result.ref) ~ " via " ~ toText(result.tree)
case result: SearchFailure =>
result.reason match {
case _: NoMatchingImplicits => "No Matching Implicit"
case _: DivergingImplicit => "Diverging Implicit"
case _: ShadowedImplicit => "Shadowed Implicit"
case result: AmbiguousImplicits =>
"Ambiguous Implicit: " ~ toText(result.alt1.ref) ~ " and " ~ toText(result.alt2.ref)
case _ =>
"?Unknown Implicit Result?" + result.getClass
}
}
def toText(importInfo: ImportInfo): Text = {
val siteStr = importInfo.site.show
val exprStr = if (siteStr endsWith ".type") siteStr dropRight 5 else siteStr
val selectorStr = importInfo.selectors match {
case Ident(name) :: Nil => name.show
case _ => "{...}"
}
s"import $exprStr.$selectorStr"
}
private[this] var maxSummarized = Int.MaxValue
def summarized[T](depth: Int)(op: => T): T = {
val saved = maxSummarized
maxSummarized = ctx.toTextRecursions + depth
try op
finally maxSummarized = depth
}
def summarized[T](op: => T): T = summarized(summarizeDepth)(op)
def plain = this
protected def keywordStr(text: String): String = coloredStr(text, SyntaxHighlighting.KeywordColor)
protected def keywordText(text: String): Text = coloredStr(text, SyntaxHighlighting.KeywordColor)
protected def valDefText(text: Text): Text = coloredText(text, SyntaxHighlighting.ValDefColor)
protected def typeText(text: Text): Text = coloredText(text, SyntaxHighlighting.TypeColor)
protected def literalText(text: Text): Text = coloredText(text, SyntaxHighlighting.LiteralColor)
protected def stringText(text: Text): Text = coloredText(text, SyntaxHighlighting.StringColor)
protected def coloredStr(text: String, color: String): String =
if (ctx.useColors) color + text + SyntaxHighlighting.NoColor else text
protected def coloredText(text: Text, color: String): Text =
if (ctx.useColors) color ~ text ~ SyntaxHighlighting.NoColor else text
}
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