Scala example source code file (Parsers.scala)
The Parsers.scala Scala example source code/* NSC -- new Scala compiler
* Copyright 2005-2013 LAMP/EPFL
* @author Martin Odersky
*/
//todo: allow infix type patterns
//todo verify when stableId's should be just plain qualified type ids
package scala.tools.nsc
package ast.parser
import scala.collection.{ mutable, immutable }
import mutable.{ ListBuffer, StringBuilder }
import scala.reflect.internal.{ Precedence, ModifierFlags => Flags }
import scala.reflect.internal.Chars.{ isScalaLetter }
import scala.reflect.internal.util.{ SourceFile, Position, FreshNameCreator }
import Tokens._
/** Historical note: JavaParsers started life as a direct copy of Parsers
* but at a time when that Parsers had been replaced by a different one.
* Later it was dropped and the original Parsers reinstated, leaving us with
* massive duplication between Parsers and JavaParsers.
*
* This trait and the similar one for Scanners/JavaScanners represents
* the beginnings of a campaign against this latest incursion by Cutty
* McPastington and his army of very similar soldiers.
*/
trait ParsersCommon extends ScannersCommon { self =>
val global : Global
// the use of currentUnit in the parser should be avoided as it might
// cause unexpected behaviour when you work with two units at the
// same time; use Parser.unit instead
import global.{currentUnit => _, _}
def newLiteral(const: Any) = Literal(Constant(const))
def literalUnit = gen.mkSyntheticUnit()
/** This is now an abstract class, only to work around the optimizer:
* methods in traits are never inlined.
*/
abstract class ParserCommon {
val in: ScannerCommon
def deprecationWarning(off: Offset, msg: String): Unit
def accept(token: Token): Int
/** Methods inParensOrError and similar take a second argument which, should
* the next token not be the expected opener (e.g. LPAREN) will be returned
* instead of the contents of the groupers. However in all cases accept(LPAREN)
* will be called, so a parse error will still result. If the grouping is
* optional, in.token should be tested before calling these methods.
*/
@inline final def inParens[T](body: => T): T = {
accept(LPAREN)
val ret = body
accept(RPAREN)
ret
}
@inline final def inParensOrError[T](body: => T, alt: T): T =
if (in.token == LPAREN) inParens(body)
else { accept(LPAREN) ; alt }
@inline final def inParensOrUnit[T](body: => Tree): Tree = inParensOrError(body, literalUnit)
@inline final def inParensOrNil[T](body: => List[T]): List[T] = inParensOrError(body, Nil)
@inline final def inBraces[T](body: => T): T = {
accept(LBRACE)
val ret = body
accept(RBRACE)
ret
}
@inline final def inBracesOrError[T](body: => T, alt: T): T =
if (in.token == LBRACE) inBraces(body)
else { accept(LBRACE) ; alt }
@inline final def inBracesOrNil[T](body: => List[T]): List[T] = inBracesOrError(body, Nil)
@inline final def inBracesOrUnit[T](body: => Tree): Tree = inBracesOrError(body, literalUnit)
@inline final def dropAnyBraces[T](body: => T): T =
if (in.token == LBRACE) inBraces(body)
else body
@inline final def inBrackets[T](body: => T): T = {
accept(LBRACKET)
val ret = body
accept(RBRACKET)
ret
}
/** Creates an actual Parens node (only used during parsing.)
*/
@inline final def makeParens(body: => List[Tree]): Parens =
Parens(inParens(if (in.token == RPAREN) Nil else body))
}
}
/** Performs the following context-free rewritings:
*
* <ol>
* <li>
* Places all pattern variables in Bind nodes. In a pattern, for
* identifiers `x`:<pre>
* x => x @ _
* x:T => x @ (_ : T)</pre>
* </li>
* <li>Removes pattern definitions (PatDef's) as follows:
* If pattern is a simple (typed) identifier:<pre>
* <b>val</b> x = e ==> <b>val</b> x = e
* <b>val</b> x: T = e ==> <b>val</b> x: T = e</pre>
*
* if there are no variables in pattern<pre>
* <b>val</b> p = e ==> e match (case p => ())</pre>
*
* if there is exactly one variable in pattern<pre>
* <b>val</b> x_1 = e <b>match</b> (case p => (x_1))</pre>
*
* if there is more than one variable in pattern<pre>
* <b>val</b> p = e ==> <b>private synthetic val</b> t$ = e <b>match</b> (case p => (x_1, ..., x_N))
* <b>val</b> x_1 = t$._1
* ...
* <b>val</b> x_N = t$._N</pre>
* </li>
* <li>
* Removes function types as follows:<pre>
* (argtpes) => restpe ==> scala.Function_n[argtpes, restpe]</pre>
* </li>
* <li>
* Wraps naked case definitions in a match as follows:<pre>
* { cases } ==> (x => x.match {cases})<span style="font-family:normal;">, except when already argument to match</span></pre>
* </li>
* </ol>
*/
trait Parsers extends Scanners with MarkupParsers with ParsersCommon {
self =>
val global: Global
import global._
case class OpInfo(lhs: Tree, operator: TermName, targs: List[Tree], offset: Offset) {
def precedence = Precedence(operator.toString)
}
class SourceFileParser(val source: SourceFile) extends Parser {
/** The parse starting point depends on whether the source file is self-contained:
* if not, the AST will be supplemented.
*/
def parseStartRule =
if (source.isSelfContained) () => compilationUnit()
else () => scriptBody()
def newScanner(): Scanner = new SourceFileScanner(source)
val in = newScanner()
in.init()
def unit = global.currentUnit
// suppress warnings; silent abort on errors
def warning(offset: Offset, msg: String) {}
def deprecationWarning(offset: Offset, msg: String) {}
def syntaxError(offset: Offset, msg: String): Unit = throw new MalformedInput(offset, msg)
def incompleteInputError(msg: String): Unit = throw new MalformedInput(source.content.length - 1, msg)
object symbXMLBuilder extends SymbolicXMLBuilder(this, preserveWS = true) { // DEBUG choices
val global: self.global.type = self.global
}
/** the markup parser
* The first time this lazy val is accessed, we assume we were trying to parse an xml literal.
* The current position is recorded for later error reporting if it turns out
* that we don't have the xml library on the compilation classpath.
*/
private[this] lazy val xmlp = {
unit.encounteredXml(o2p(in.offset))
new MarkupParser(this, preserveWS = true)
}
def xmlLiteral() : Tree = xmlp.xLiteral
def xmlLiteralPattern() : Tree = xmlp.xLiteralPattern
}
class OutlineParser(source: SourceFile) extends SourceFileParser(source) {
def skipBraces[T](body: T): T = {
accept(LBRACE)
var openBraces = 1
while (in.token != EOF && openBraces > 0) {
if (in.token == XMLSTART) xmlLiteral()
else {
if (in.token == LBRACE) openBraces += 1
else if (in.token == RBRACE) openBraces -= 1
in.nextToken()
}
}
body
}
override def blockExpr(): Tree = skipBraces(EmptyTree)
override def templateBody(isPre: Boolean) = skipBraces((noSelfType, EmptyTree.asList))
}
class UnitParser(override val unit: global.CompilationUnit, patches: List[BracePatch]) extends SourceFileParser(unit.source) { uself =>
def this(unit: global.CompilationUnit) = this(unit, Nil)
override def newScanner() = new UnitScanner(unit, patches)
override def warning(offset: Offset, msg: String) {
unit.warning(o2p(offset), msg)
}
override def deprecationWarning(offset: Offset, msg: String) {
unit.deprecationWarning(o2p(offset), msg)
}
private var smartParsing = false
@inline private def withSmartParsing[T](body: => T): T = {
val saved = smartParsing
smartParsing = true
try body
finally smartParsing = saved
}
def withPatches(patches: List[BracePatch]): UnitParser = new UnitParser(unit, patches)
val syntaxErrors = new ListBuffer[(Int, String)]
def showSyntaxErrors() =
for ((offset, msg) <- syntaxErrors)
unit.error(o2p(offset), msg)
override def syntaxError(offset: Offset, msg: String) {
if (smartParsing) syntaxErrors += ((offset, msg))
else unit.error(o2p(offset), msg)
}
override def incompleteInputError(msg: String) {
val offset = source.content.length - 1
if (smartParsing) syntaxErrors += ((offset, msg))
else unit.incompleteInputError(o2p(offset), msg)
}
/** parse unit. If there are inbalanced braces,
* try to correct them and reparse.
*/
def smartParse(): Tree = withSmartParsing {
val firstTry = parse()
if (syntaxErrors.isEmpty) firstTry
else in.healBraces() match {
case Nil => showSyntaxErrors() ; firstTry
case patches => (this withPatches patches).parse()
}
}
}
type Location = Int
final val Local: Location = 0
final val InBlock: Location = 1
final val InTemplate: Location = 2
// These symbols may not yet be loaded (e.g. in the ide) so don't go
// through definitions to obtain the names.
lazy val ScalaValueClassNames = Seq(tpnme.AnyVal,
tpnme.Unit,
tpnme.Boolean,
tpnme.Byte,
tpnme.Short,
tpnme.Char,
tpnme.Int,
tpnme.Long,
tpnme.Float,
tpnme.Double)
import nme.raw
abstract class Parser extends ParserCommon { parser =>
val in: Scanner
def unit: CompilationUnit
def source: SourceFile
/** Scoping operator used to temporarily look into the future.
* Backs up scanner data before evaluating a block and restores it after.
*/
@inline final def lookingAhead[T](body: => T): T = {
val saved = new ScannerData {} copyFrom in
in.nextToken()
try body finally in copyFrom saved
}
/** Perform an operation while peeking ahead.
* Pushback if the operation yields an empty tree or blows to pieces.
*/
@inline def peekingAhead(tree: =>Tree): Tree = {
@inline def peekahead() = {
in.prev copyFrom in
in.nextToken()
}
@inline def pushback() = {
in.next copyFrom in
in copyFrom in.prev
}
peekahead()
// try it, in case it is recoverable
val res = try tree catch { case e: Exception => pushback() ; throw e }
if (res.isEmpty) pushback()
res
}
class ParserTreeBuilder extends TreeBuilder {
val global: self.global.type = self.global
def unit = parser.unit
def source = parser.source
}
val treeBuilder = new ParserTreeBuilder
import treeBuilder.{global => _, unit => _, source => _, fresh => _, _}
implicit def fresh: FreshNameCreator = unit.fresh
def o2p(offset: Offset): Position = Position.offset(source, offset)
def r2p(start: Offset, mid: Offset, end: Offset): Position = rangePos(source, start, mid, end)
def r2p(start: Offset, mid: Offset): Position = r2p(start, mid, in.lastOffset max start)
def r2p(offset: Offset): Position = r2p(offset, offset)
/** whether a non-continuable syntax error has been seen */
private var lastErrorOffset : Int = -1
/** The types of the context bounds of type parameters of the surrounding class
*/
private var classContextBounds: List[Tree] = Nil
@inline private def savingClassContextBounds[T](op: => T): T = {
val saved = classContextBounds
try op
finally classContextBounds = saved
}
/** Are we inside the Scala package? Set for files that start with package scala
*/
private var inScalaPackage = false
private var currentPackage = ""
def resetPackage() {
inScalaPackage = false
currentPackage = ""
}
private def inScalaRootPackage = inScalaPackage && currentPackage == "scala"
def parseStartRule: () => Tree
def parseRule[T](rule: this.type => T): T = {
val t = rule(this)
accept(EOF)
t
}
/** This is the general parse entry point.
*/
def parse(): Tree = parseRule(_.parseStartRule())
/** These are alternative entry points for repl, script runner, toolbox and parsing in macros.
*/
def parseStats(): List[Tree] = parseRule(_.templateStats())
def parseStatsOrPackages(): List[Tree] = parseRule(_.templateOrTopStatSeq())
/** This is the parse entry point for code which is not self-contained, e.g.
* a script which is a series of template statements. They will be
* swaddled in Trees until the AST is equivalent to the one returned
* by compilationUnit().
*/
def scriptBody(): Tree = {
val stmts = parseStats()
def mainModuleName = newTermName(settings.script.value)
/* If there is only a single object template in the file and it has a
* suitable main method, we will use it rather than building another object
* around it. Since objects are loaded lazily the whole script would have
* been a no-op, so we're not taking much liberty.
*/
def searchForMain(): Option[Tree] = {
/* Have to be fairly liberal about what constitutes a main method since
* nothing has been typed yet - for instance we can't assume the parameter
* type will look exactly like "Array[String]" as it could have been renamed
* via import, etc.
*/
def isMainMethod(t: Tree) = t match {
case DefDef(_, nme.main, Nil, List(_), _, _) => true
case _ => false
}
/* For now we require there only be one top level object. */
var seenModule = false
val newStmts = stmts collect {
case t @ Import(_, _) => t
case md @ ModuleDef(mods, name, template) if !seenModule && (md exists isMainMethod) =>
seenModule = true
/* This slightly hacky situation arises because we have no way to communicate
* back to the scriptrunner what the name of the program is. Even if we were
* willing to take the sketchy route of settings.script.value = progName, that
* does not work when using fsc. And to find out in advance would impose a
* whole additional parse. So instead, if the actual object's name differs from
* what the script is expecting, we transform it to match.
*/
if (name == mainModuleName) md
else treeCopy.ModuleDef(md, mods, mainModuleName, template)
case _ =>
/* If we see anything but the above, fail. */
return None
}
Some(makeEmptyPackage(0, newStmts))
}
if (mainModuleName == newTermName(ScriptRunner.defaultScriptMain))
searchForMain() foreach { return _ }
/* Here we are building an AST representing the following source fiction,
* where `moduleName` is from -Xscript (defaults to "Main") and <stmts> are
* the result of parsing the script file.
*
* {{{
* object moduleName {
* def main(args: Array[String]): Unit =
* new AnyRef {
* stmts
* }
* }
* }}}
*/
def emptyInit = DefDef(
NoMods,
nme.CONSTRUCTOR,
Nil,
ListOfNil,
TypeTree(),
Block(List(Apply(gen.mkSuperInitCall, Nil)), literalUnit)
)
// def main
def mainParamType = AppliedTypeTree(Ident(tpnme.Array), List(Ident(tpnme.String)))
def mainParameter = List(ValDef(Modifiers(Flags.PARAM), nme.args, mainParamType, EmptyTree))
def mainDef = DefDef(NoMods, nme.main, Nil, List(mainParameter), scalaDot(tpnme.Unit), gen.mkAnonymousNew(stmts))
// object Main
def moduleName = newTermName(ScriptRunner scriptMain settings)
def moduleBody = Template(atInPos(scalaAnyRefConstr) :: Nil, noSelfType, List(emptyInit, mainDef))
def moduleDef = ModuleDef(NoMods, moduleName, moduleBody)
// package <empty> { ... }
makeEmptyPackage(0, moduleDef :: Nil)
}
/* --------------- PLACEHOLDERS ------------------------------------------- */
/** The implicit parameters introduced by `_` in the current expression.
* Parameters appear in reverse order.
*/
var placeholderParams: List[ValDef] = Nil
/** The placeholderTypes introduced by `_` in the current type.
* Parameters appear in reverse order.
*/
var placeholderTypes: List[TypeDef] = Nil
def checkNoEscapingPlaceholders[T](op: => T): T = {
val savedPlaceholderParams = placeholderParams
val savedPlaceholderTypes = placeholderTypes
placeholderParams = List()
placeholderTypes = List()
val res = op
placeholderParams match {
case vd :: _ =>
syntaxError(vd.pos, "unbound placeholder parameter", skipIt = false)
placeholderParams = List()
case _ =>
}
placeholderTypes match {
case td :: _ =>
syntaxError(td.pos, "unbound wildcard type", skipIt = false)
placeholderTypes = List()
case _ =>
}
placeholderParams = savedPlaceholderParams
placeholderTypes = savedPlaceholderTypes
res
}
def placeholderTypeBoundary(op: => Tree): Tree = {
val savedPlaceholderTypes = placeholderTypes
placeholderTypes = List()
var t = op
if (!placeholderTypes.isEmpty && t.isInstanceOf[AppliedTypeTree]) {
val expos = t.pos
ensureNonOverlapping(t, placeholderTypes)
t = atPos(expos) { ExistentialTypeTree(t, placeholderTypes.reverse) }
placeholderTypes = List()
}
placeholderTypes = placeholderTypes ::: savedPlaceholderTypes
t
}
def isWildcard(t: Tree): Boolean = t match {
case Ident(name1) => !placeholderParams.isEmpty && name1 == placeholderParams.head.name
case Typed(t1, _) => isWildcard(t1)
case Annotated(t1, _) => isWildcard(t1)
case _ => false
}
/* ------------- ERROR HANDLING ------------------------------------------- */
val assumedClosingParens = mutable.Map(RPAREN -> 0, RBRACKET -> 0, RBRACE -> 0)
private var inFunReturnType = false
@inline private def fromWithinReturnType[T](body: => T): T = {
val saved = inFunReturnType
inFunReturnType = true
try body
finally inFunReturnType = saved
}
protected def skip(targetToken: Token) {
var nparens = 0
var nbraces = 0
while (true) {
in.token match {
case EOF =>
return
case SEMI =>
if (nparens == 0 && nbraces == 0) return
case NEWLINE =>
if (nparens == 0 && nbraces == 0) return
case NEWLINES =>
if (nparens == 0 && nbraces == 0) return
case RPAREN =>
nparens -= 1
case RBRACE =>
if (nbraces == 0) return
nbraces -= 1
case LPAREN =>
nparens += 1
case LBRACE =>
nbraces += 1
case _ =>
}
if (targetToken == in.token && nparens == 0 && nbraces == 0) return
in.nextToken()
}
}
def warning(offset: Offset, msg: String): Unit
def incompleteInputError(msg: String): Unit
private def syntaxError(pos: Position, msg: String, skipIt: Boolean) {
syntaxError(pos pointOrElse in.offset, msg, skipIt)
}
def syntaxError(offset: Offset, msg: String): Unit
def syntaxError(msg: String, skipIt: Boolean) {
syntaxError(in.offset, msg, skipIt)
}
def syntaxError(offset: Offset, msg: String, skipIt: Boolean) {
if (offset > lastErrorOffset) {
syntaxError(offset, msg)
// no more errors on this token.
lastErrorOffset = in.offset
}
if (skipIt)
skip(UNDEF)
}
def warning(msg: String) { warning(in.offset, msg) }
def syntaxErrorOrIncomplete(msg: String, skipIt: Boolean) {
if (in.token == EOF)
incompleteInputError(msg)
else
syntaxError(in.offset, msg, skipIt)
}
def syntaxErrorOrIncompleteAnd[T](msg: String, skipIt: Boolean)(and: T): T = {
syntaxErrorOrIncomplete(msg, skipIt)
and
}
def expectedMsgTemplate(exp: String, fnd: String) = s"$exp expected but $fnd found."
def expectedMsg(token: Token): String = expectedMsgTemplate(token2string(token), token2string(in.token))
/** Consume one token of the specified type, or signal an error if it is not there. */
def accept(token: Token): Offset = {
val offset = in.offset
if (in.token != token) {
syntaxErrorOrIncomplete(expectedMsg(token), skipIt = false)
if ((token == RPAREN || token == RBRACE || token == RBRACKET))
if (in.parenBalance(token) + assumedClosingParens(token) < 0)
assumedClosingParens(token) += 1
else
skip(token)
else
skip(UNDEF)
}
if (in.token == token) in.nextToken()
offset
}
/** {{{
* semi = nl {nl} | `;`
* nl = `\n' // where allowed
* }}}
*/
def acceptStatSep(): Unit = in.token match {
case NEWLINE | NEWLINES => in.nextToken()
case _ => accept(SEMI)
}
def acceptStatSepOpt() =
if (!isStatSeqEnd)
acceptStatSep()
def errorTypeTree = setInPos(TypeTree() setType ErrorType)
def errorTermTree = setInPos(newLiteral(null))
def errorPatternTree = setInPos(Ident(nme.WILDCARD))
/** Check that type parameter is not by name or repeated. */
def checkNotByNameOrVarargs(tpt: Tree) = {
if (treeInfo isByNameParamType tpt)
syntaxError(tpt.pos, "no by-name parameter type allowed here", skipIt = false)
else if (treeInfo isRepeatedParamType tpt)
syntaxError(tpt.pos, "no * parameter type allowed here", skipIt = false)
}
/* -------------- TOKEN CLASSES ------------------------------------------- */
def isModifier: Boolean = in.token match {
case ABSTRACT | FINAL | SEALED | PRIVATE |
PROTECTED | OVERRIDE | IMPLICIT | LAZY => true
case _ => false
}
def isAnnotation: Boolean = in.token == AT
def isLocalModifier: Boolean = in.token match {
case ABSTRACT | FINAL | SEALED | IMPLICIT | LAZY => true
case _ => false
}
def isTemplateIntro: Boolean = in.token match {
case OBJECT | CASEOBJECT | CLASS | CASECLASS | TRAIT => true
case _ => false
}
def isDclIntro: Boolean = in.token match {
case VAL | VAR | DEF | TYPE => true
case _ => false
}
def isDefIntro = isTemplateIntro || isDclIntro
def isNumericLit: Boolean = in.token match {
case INTLIT | LONGLIT | FLOATLIT | DOUBLELIT => true
case _ => false
}
def isIdentExcept(except: Name) = isIdent && in.name != except
def isIdentOf(name: Name) = isIdent && in.name == name
def isUnaryOp = isIdent && raw.isUnary(in.name)
def isRawStar = isRawIdent && in.name == raw.STAR
def isRawBar = isRawIdent && in.name == raw.BAR
def isRawIdent = in.token == IDENTIFIER
def isIdent = in.token == IDENTIFIER || in.token == BACKQUOTED_IDENT
def isMacro = in.token == IDENTIFIER && in.name == nme.MACROkw
def isLiteralToken(token: Token) = token match {
case CHARLIT | INTLIT | LONGLIT | FLOATLIT | DOUBLELIT |
STRINGLIT | INTERPOLATIONID | SYMBOLLIT | TRUE | FALSE | NULL => true
case _ => false
}
def isLiteral = isLiteralToken(in.token)
def isExprIntroToken(token: Token): Boolean = isLiteralToken(token) || (token match {
case IDENTIFIER | BACKQUOTED_IDENT |
THIS | SUPER | IF | FOR | NEW | USCORE | TRY | WHILE |
DO | RETURN | THROW | LPAREN | LBRACE | XMLSTART => true
case _ => false
})
def isExprIntro: Boolean = isExprIntroToken(in.token)
def isTypeIntroToken(token: Token): Boolean = token match {
case IDENTIFIER | BACKQUOTED_IDENT | THIS |
SUPER | USCORE | LPAREN | AT => true
case _ => false
}
def isStatSeqEnd = in.token == RBRACE || in.token == EOF
def isCaseDefEnd = in.token == RBRACE || in.token == CASE || in.token == EOF
def isStatSep(token: Token): Boolean =
token == NEWLINE || token == NEWLINES || token == SEMI
def isStatSep: Boolean = isStatSep(in.token)
/* --------- COMMENT AND ATTRIBUTE COLLECTION ----------------------------- */
/** A hook for joining the comment associated with a definition.
* Overridden by scaladoc.
*/
def joinComment(trees: => List[Tree]): List[Tree] = trees
/* ---------- TREE CONSTRUCTION ------------------------------------------- */
def atPos[T <: Tree](offset: Offset)(t: T): T = atPos(r2p(offset))(t)
def atPos[T <: Tree](start: Offset, point: Offset)(t: T): T = atPos(r2p(start, point))(t)
def atPos[T <: Tree](start: Offset, point: Offset, end: Offset)(t: T): T = atPos(r2p(start, point, end))(t)
def atPos[T <: Tree](pos: Position)(t: T): T = global.atPos(pos)(t)
def atInPos[T <: Tree](t: T): T = atPos(o2p(in.offset))(t)
def setInPos[T <: Tree](t: T): T = t setPos o2p(in.offset)
/** Convert tree to formal parameter list. */
def convertToParams(tree: Tree): List[ValDef] = tree match {
case Parens(ts) => ts map convertToParam
case _ => List(convertToParam(tree))
}
/** Convert tree to formal parameter. */
def convertToParam(tree: Tree): ValDef = atPos(tree.pos) {
def removeAsPlaceholder(name: Name) {
placeholderParams = placeholderParams filter (_.name != name)
}
def errorParam = makeParam(nme.ERROR, errorTypeTree setPos o2p(tree.pos.end))
tree match {
case Ident(name) =>
removeAsPlaceholder(name)
makeParam(name.toTermName, TypeTree() setPos o2p(tree.pos.end))
case Typed(Ident(name), tpe) if tpe.isType => // get the ident!
removeAsPlaceholder(name)
makeParam(name.toTermName, tpe)
case build.SyntacticTuple(as) =>
val arity = as.length
val example = analyzer.exampleTuplePattern(as map { case Ident(name) => name; case _ => nme.EMPTY })
val msg =
sm"""|not a legal formal parameter.
|Note: Tuples cannot be directly destructured in method or function parameters.
| Either create a single parameter accepting the Tuple${arity},
| or consider a pattern matching anonymous function: `{ case $example => ... }"""
syntaxError(tree.pos, msg, skipIt = false)
errorParam
case _ =>
syntaxError(tree.pos, "not a legal formal parameter", skipIt = false)
errorParam
}
}
/** Convert (qual)ident to type identifier. */
def convertToTypeId(tree: Tree): Tree = atPos(tree.pos) {
convertToTypeName(tree) getOrElse {
syntaxError(tree.pos, "identifier expected", skipIt = false)
errorTypeTree
}
}
/** {{{ part { `sep` part } }}},or if sepFirst is true, {{{ { `sep` part } }}}. */
final def tokenSeparated[T](separator: Token, sepFirst: Boolean, part: => T): List[T] = {
val ts = new ListBuffer[T]
if (!sepFirst)
ts += part
while (in.token == separator) {
in.nextToken()
ts += part
}
ts.toList
}
@inline final def commaSeparated[T](part: => T): List[T] = tokenSeparated(COMMA, sepFirst = false, part)
@inline final def caseSeparated[T](part: => T): List[T] = tokenSeparated(CASE, sepFirst = true, part)
def readAnnots(part: => Tree): List[Tree] = tokenSeparated(AT, sepFirst = true, part)
/* --------- OPERAND/OPERATOR STACK --------------------------------------- */
/** Modes for infix types. */
object InfixMode extends Enumeration {
val FirstOp, LeftOp, RightOp = Value
}
var opstack: List[OpInfo] = Nil
@deprecated("Use `scala.reflect.internal.Precedence`", "2.11.0")
def precedence(operator: Name): Int = Precedence(operator.toString).level
private def opHead = opstack.head
private def headPrecedence = opHead.precedence
private def popOpInfo(): OpInfo = try opHead finally opstack = opstack.tail
private def pushOpInfo(top: Tree): Unit = {
val name = in.name
val offset = in.offset
ident()
val targs = if (in.token == LBRACKET) exprTypeArgs() else Nil
val opinfo = OpInfo(top, name, targs, offset)
opstack ::= opinfo
}
def checkHeadAssoc(leftAssoc: Boolean) = checkAssoc(opHead.offset, opHead.operator, leftAssoc)
def checkAssoc(offset: Offset, op: Name, leftAssoc: Boolean) = (
if (treeInfo.isLeftAssoc(op) != leftAssoc)
syntaxError(offset, "left- and right-associative operators with same precedence may not be mixed", skipIt = false)
)
def finishPostfixOp(start: Int, base: List[OpInfo], opinfo: OpInfo): Tree = {
if (opinfo.targs.nonEmpty)
syntaxError(opinfo.offset, "type application is not allowed for postfix operators")
val od = stripParens(reduceExprStack(base, opinfo.lhs))
makePostfixSelect(start, opinfo.offset, od, opinfo.operator)
}
def finishBinaryOp(isExpr: Boolean, opinfo: OpInfo, rhs: Tree): Tree = {
import opinfo._
val operatorPos: Position = Position.range(rhs.pos.source, offset, offset, offset + operator.length)
val pos = lhs.pos union rhs.pos union operatorPos withPoint offset
atPos(pos)(makeBinop(isExpr, lhs, operator, rhs, operatorPos, opinfo.targs))
}
def reduceExprStack(base: List[OpInfo], top: Tree): Tree = reduceStack(isExpr = true, base, top)
def reducePatternStack(base: List[OpInfo], top: Tree): Tree = reduceStack(isExpr = false, base, top)
def reduceStack(isExpr: Boolean, base: List[OpInfo], top: Tree): Tree = {
val opPrecedence = if (isIdent) Precedence(in.name.toString) else Precedence(0)
val leftAssoc = !isIdent || (treeInfo isLeftAssoc in.name)
reduceStack(isExpr, base, top, opPrecedence, leftAssoc)
}
def reduceStack(isExpr: Boolean, base: List[OpInfo], top: Tree, opPrecedence: Precedence, leftAssoc: Boolean): Tree = {
def isDone = opstack == base
def lowerPrecedence = !isDone && (opPrecedence < headPrecedence)
def samePrecedence = !isDone && (opPrecedence == headPrecedence)
def canReduce = lowerPrecedence || leftAssoc && samePrecedence
if (samePrecedence)
checkHeadAssoc(leftAssoc)
def loop(top: Tree): Tree = if (canReduce) {
val info = popOpInfo()
if (!isExpr && info.targs.nonEmpty) {
syntaxError(info.offset, "type application is not allowed in pattern")
info.targs.foreach(_.setType(ErrorType))
}
loop(finishBinaryOp(isExpr, info, top))
} else top
loop(top)
}
/* -------- IDENTIFIERS AND LITERALS ------------------------------------------- */
/** Methods which implicitly propagate the context in which they were
* called: either in a pattern context or not. Formerly, this was
* threaded through numerous methods as boolean isPattern.
*/
trait PatternContextSensitive {
/** {{{
* ArgType ::= Type
* }}}
*/
def argType(): Tree
def functionArgType(): Tree
private def tupleInfixType(start: Offset) = {
in.nextToken()
if (in.token == RPAREN) {
in.nextToken()
atPos(start, accept(ARROW)) { makeFunctionTypeTree(Nil, typ()) }
}
else {
val ts = functionTypes()
accept(RPAREN)
if (in.token == ARROW)
atPos(start, in.skipToken()) { makeFunctionTypeTree(ts, typ()) }
else {
ts foreach checkNotByNameOrVarargs
val tuple = atPos(start) { makeTupleType(ts) }
infixTypeRest(
compoundTypeRest(
annotTypeRest(
simpleTypeRest(
tuple))),
InfixMode.FirstOp
)
}
}
}
private def makeExistentialTypeTree(t: Tree) = {
// EmptyTrees in the result of refinement() stand for parse errors
// so it's okay for us to filter them out here
ExistentialTypeTree(t, refinement() flatMap {
case t @ TypeDef(_, _, _, TypeBoundsTree(_, _)) => Some(t)
case t @ ValDef(_, _, _, EmptyTree) => Some(t)
case EmptyTree => None
case _ => syntaxError(t.pos, "not a legal existential clause", skipIt = false); None
})
}
/** {{{
* Type ::= InfixType `=>' Type
* | `(' [`=>' Type] `)' `=>' Type
* | InfixType [ExistentialClause]
* ExistentialClause ::= forSome `{' ExistentialDcl {semi ExistentialDcl}} `}'
* ExistentialDcl ::= type TypeDcl | val ValDcl
* }}}
*/
def typ(): Tree = placeholderTypeBoundary {
val start = in.offset
val t =
if (in.token == LPAREN) tupleInfixType(start)
else infixType(InfixMode.FirstOp)
in.token match {
case ARROW => atPos(start, in.skipToken()) { makeFunctionTypeTree(List(t), typ()) }
case FORSOME => atPos(start, in.skipToken()) { makeExistentialTypeTree(t) }
case _ => t
}
}
/** {{{
* TypeArgs ::= `[' ArgType {`,' ArgType} `]'
* }}}
*/
def typeArgs(): List[Tree] = inBrackets(types())
/** {{{
* AnnotType ::= SimpleType {Annotation}
* }}}
*/
def annotType(): Tree = placeholderTypeBoundary { annotTypeRest(simpleType()) }
/** {{{
* SimpleType ::= SimpleType TypeArgs
* | SimpleType `#' Id
* | StableId
* | Path `.' type
* | `(' Types `)'
* | WildcardType
* }}}
*/
def simpleType(): Tree = {
val start = in.offset
simpleTypeRest(in.token match {
case LPAREN => atPos(start)(makeTupleType(inParens(types())))
case USCORE => wildcardType(in.skipToken())
case _ =>
path(thisOK = false, typeOK = true) match {
case r @ SingletonTypeTree(_) => r
case r => convertToTypeId(r)
}
})
}
private def typeProjection(t: Tree): Tree = {
val hashOffset = in.skipToken()
val nameOffset = in.offset
val name = identForType(skipIt = false)
val point = if (name == tpnme.ERROR) hashOffset else nameOffset
atPos(t.pos.start, point)(SelectFromTypeTree(t, name))
}
def simpleTypeRest(t: Tree): Tree = in.token match {
case HASH => simpleTypeRest(typeProjection(t))
case LBRACKET => simpleTypeRest(atPos(t.pos.start, t.pos.point)(AppliedTypeTree(t, typeArgs())))
case _ => t
}
/** {{{
* CompoundType ::= AnnotType {with AnnotType} [Refinement]
* | Refinement
* }}}
*/
def compoundType(): Tree = compoundTypeRest(
if (in.token == LBRACE) atInPos(scalaAnyRefConstr)
else annotType()
)
def compoundTypeRest(t: Tree): Tree = {
val ts = new ListBuffer[Tree] += t
while (in.token == WITH) {
in.nextToken()
ts += annotType()
}
newLineOptWhenFollowedBy(LBRACE)
val types = ts.toList
val braceOffset = in.offset
val hasRefinement = in.token == LBRACE
val refinements = if (hasRefinement) refinement() else Nil
// Warn if they are attempting to refine Unit; we can't be certain it's
// scala.Unit they're refining because at this point all we have is an
// identifier, but at a later stage we lose the ability to tell an empty
// refinement from no refinement at all. See bug #284.
if (hasRefinement) types match {
case Ident(name) :: Nil if name endsWith "Unit" => warning(braceOffset, "Detected apparent refinement of Unit; are you missing an '=' sign?")
case _ =>
}
// The second case includes an empty refinement - refinements is empty, but
// it still gets a CompoundTypeTree.
ts.toList match {
case tp :: Nil if !hasRefinement => tp // single type, no refinement, already positioned
case tps => atPos(t.pos.start)(CompoundTypeTree(Template(tps, noSelfType, refinements)))
}
}
def infixTypeRest(t: Tree, mode: InfixMode.Value): Tree = {
// Detect postfix star for repeated args.
// Only RPAREN can follow, but accept COMMA and EQUALS for error's sake.
// Take RBRACE as a paren typo.
def checkRepeatedParam = if (isRawStar) {
lookingAhead (in.token match {
case RPAREN | COMMA | EQUALS | RBRACE => t
case _ => EmptyTree
})
} else EmptyTree
def asInfix = {
val opOffset = in.offset
val leftAssoc = treeInfo.isLeftAssoc(in.name)
if (mode != InfixMode.FirstOp)
checkAssoc(opOffset, in.name, leftAssoc = mode == InfixMode.LeftOp)
val tycon = atPos(opOffset) { Ident(identForType()) }
newLineOptWhenFollowing(isTypeIntroToken)
def mkOp(t1: Tree) = atPos(t.pos.start, opOffset) { AppliedTypeTree(tycon, List(t, t1)) }
if (leftAssoc)
infixTypeRest(mkOp(compoundType()), InfixMode.LeftOp)
else
mkOp(infixType(InfixMode.RightOp))
}
if (isIdent) checkRepeatedParam orElse asInfix
else t
}
/** {{{
* InfixType ::= CompoundType {id [nl] CompoundType}
* }}}
*/
def infixType(mode: InfixMode.Value): Tree =
placeholderTypeBoundary { infixTypeRest(compoundType(), mode) }
/** {{{
* Types ::= Type {`,' Type}
* }}}
*/
def types(): List[Tree] = commaSeparated(argType())
def functionTypes(): List[Tree] = commaSeparated(functionArgType())
}
/** Assumed (provisionally) to be TermNames. */
def ident(skipIt: Boolean): Name = (
if (isIdent) {
val name = in.name.encode
in.nextToken()
name
}
else syntaxErrorOrIncompleteAnd(expectedMsg(IDENTIFIER), skipIt)(nme.ERROR)
)
def ident(): Name = ident(skipIt = true)
def rawIdent(): Name = try in.name finally in.nextToken()
/** For when it's known already to be a type name. */
def identForType(): TypeName = ident().toTypeName
def identForType(skipIt: Boolean): TypeName = ident(skipIt).toTypeName
def identOrMacro(): Name = if (isMacro) rawIdent() else ident()
def selector(t: Tree): Tree = {
val point = in.offset
//assert(t.pos.isDefined, t)
if (t != EmptyTree)
Select(t, ident(skipIt = false)) setPos r2p(t.pos.start, point, in.lastOffset)
else
errorTermTree // has already been reported
}
/** {{{
* Path ::= StableId
* | [Ident `.'] this
* AnnotType ::= Path [`.' type]
* }}}
*/
def path(thisOK: Boolean, typeOK: Boolean): Tree = {
val start = in.offset
var t: Tree = null
if (in.token == THIS) {
in.nextToken()
t = atPos(start) { This(tpnme.EMPTY) }
if (!thisOK || in.token == DOT) {
t = selectors(t, typeOK, accept(DOT))
}
} else if (in.token == SUPER) {
in.nextToken()
t = atPos(start) { Super(This(tpnme.EMPTY), mixinQualifierOpt()) }
accept(DOT)
t = selector(t)
if (in.token == DOT) t = selectors(t, typeOK, in.skipToken())
} else {
val tok = in.token
val name = ident()
t = atPos(start) {
if (tok == BACKQUOTED_IDENT) Ident(name) updateAttachment BackquotedIdentifierAttachment
else Ident(name)
}
if (in.token == DOT) {
val dotOffset = in.skipToken()
if (in.token == THIS) {
in.nextToken()
t = atPos(start) { This(name.toTypeName) }
if (!thisOK || in.token == DOT)
t = selectors(t, typeOK, accept(DOT))
} else if (in.token == SUPER) {
in.nextToken()
t = atPos(start) { Super(This(name.toTypeName), mixinQualifierOpt()) }
accept(DOT)
t = selector(t)
if (in.token == DOT) t = selectors(t, typeOK, in.skipToken())
} else {
t = selectors(t, typeOK, dotOffset)
}
}
}
t
}
def selectors(t: Tree, typeOK: Boolean, dotOffset: Offset): Tree =
if (typeOK && in.token == TYPE) {
in.nextToken()
atPos(t.pos.start, dotOffset) { SingletonTypeTree(t) }
}
else {
val t1 = selector(t)
if (in.token == DOT) { selectors(t1, typeOK, in.skipToken()) }
else t1
}
/** {{{
* MixinQualifier ::= `[' Id `]'
* }}}
*/
def mixinQualifierOpt(): TypeName =
if (in.token == LBRACKET) inBrackets(identForType())
else tpnme.EMPTY
/** {{{
* StableId ::= Id
* | Path `.' Id
* | [id `.'] super [`[' id `]']`.' id
* }}}
*/
def stableId(): Tree =
path(thisOK = false, typeOK = false)
/** {{{
* QualId ::= Id {`.' Id}
* }}}
*/
def qualId(): Tree = {
val start = in.offset
val id = atPos(start) { Ident(ident()) }
if (in.token == DOT) { selectors(id, typeOK = false, in.skipToken()) }
else id
}
/** Calls `qualId()` and manages some package state. */
private def pkgQualId() = {
if (in.token == IDENTIFIER && in.name.encode == nme.scala_)
inScalaPackage = true
val pkg = qualId()
newLineOptWhenFollowedBy(LBRACE)
if (currentPackage == "") currentPackage = pkg.toString
else currentPackage = currentPackage + "." + pkg
pkg
}
/** {{{
* SimpleExpr ::= literal
* | symbol
* | null
* }}}
*/
def literal(isNegated: Boolean = false, inPattern: Boolean = false, start: Offset = in.offset): Tree = atPos(start) {
def finish(value: Any): Tree = try newLiteral(value) finally in.nextToken()
if (in.token == SYMBOLLIT)
Apply(scalaDot(nme.Symbol), List(finish(in.strVal)))
else if (in.token == INTERPOLATIONID)
interpolatedString(inPattern = inPattern)
else finish(in.token match {
case CHARLIT => in.charVal
case INTLIT => in.intVal(isNegated).toInt
case LONGLIT => in.intVal(isNegated)
case FLOATLIT => in.floatVal(isNegated).toFloat
case DOUBLELIT => in.floatVal(isNegated)
case STRINGLIT | STRINGPART => in.strVal.intern()
case TRUE => true
case FALSE => false
case NULL => null
case _ => syntaxErrorOrIncompleteAnd("illegal literal", skipIt = true)(null)
})
}
/** Handle placeholder syntax.
* If evaluating the tree produces placeholders, then make it a function.
*/
private def withPlaceholders(tree: =>Tree, isAny: Boolean): Tree = {
val savedPlaceholderParams = placeholderParams
placeholderParams = List()
var res = tree
if (placeholderParams.nonEmpty && !isWildcard(res)) {
res = atPos(res.pos)(Function(placeholderParams.reverse, res))
if (isAny) placeholderParams foreach (_.tpt match {
case tpt @ TypeTree() => tpt setType definitions.AnyTpe
case _ => // some ascription
})
placeholderParams = List()
}
placeholderParams = placeholderParams ::: savedPlaceholderParams
res
}
/** Consume a USCORE and create a fresh synthetic placeholder param. */
private def freshPlaceholder(): Tree = {
val start = in.offset
val pname = freshTermName()
in.nextToken()
val id = atPos(start)(Ident(pname))
val param = atPos(id.pos.focus)(gen.mkSyntheticParam(pname.toTermName))
placeholderParams = param :: placeholderParams
id
}
private def interpolatedString(inPattern: Boolean): Tree = {
def errpolation() = syntaxErrorOrIncompleteAnd("error in interpolated string: identifier or block expected",
skipIt = true)(EmptyTree)
// Like Swiss cheese, with holes
def stringCheese: Tree = atPos(in.offset) {
val start = in.offset
val interpolator = in.name.encoded // ident() for INTERPOLATIONID
val partsBuf = new ListBuffer[Tree]
val exprBuf = new ListBuffer[Tree]
in.nextToken()
while (in.token == STRINGPART) {
partsBuf += literal()
exprBuf += (
if (inPattern) dropAnyBraces(pattern())
else in.token match {
case IDENTIFIER => atPos(in.offset)(Ident(ident()))
//case USCORE => freshPlaceholder() // ifonly etapolation
case LBRACE => expr() // dropAnyBraces(expr0(Local))
case THIS => in.nextToken(); atPos(in.offset)(This(tpnme.EMPTY))
case _ => errpolation()
}
)
}
if (in.token == STRINGLIT) partsBuf += literal()
val t1 = atPos(o2p(start)) { Ident(nme.StringContext) }
val t2 = atPos(start) { Apply(t1, partsBuf.toList) }
t2 setPos t2.pos.makeTransparent
val t3 = Select(t2, interpolator) setPos t2.pos
atPos(start) { Apply(t3, exprBuf.toList) }
}
if (inPattern) stringCheese
else withPlaceholders(stringCheese, isAny = true) // strinterpolator params are Any* by definition
}
/* ------------- NEW LINES ------------------------------------------------- */
def newLineOpt() {
if (in.token == NEWLINE) in.nextToken()
}
def newLinesOpt() {
if (in.token == NEWLINE || in.token == NEWLINES)
in.nextToken()
}
def newLineOptWhenFollowedBy(token: Offset) {
// note: next is defined here because current == NEWLINE
if (in.token == NEWLINE && in.next.token == token) newLineOpt()
}
def newLineOptWhenFollowing(p: Token => Boolean) {
// note: next is defined here because current == NEWLINE
if (in.token == NEWLINE && p(in.next.token)) newLineOpt()
}
/* ------------- TYPES ---------------------------------------------------- */
/** {{{
* TypedOpt ::= [`:' Type]
* }}}
*/
def typedOpt(): Tree =
if (in.token == COLON) { in.nextToken(); typ() }
else TypeTree()
def typeOrInfixType(location: Location): Tree =
if (location == Local) typ()
else startInfixType()
def annotTypeRest(t: Tree): Tree =
(t /: annotations(skipNewLines = false)) (makeAnnotated)
/** {{{
* WildcardType ::= `_' TypeBounds
* }}}
*/
def wildcardType(start: Offset) = {
val pname = freshTypeName("_$")
val t = atPos(start)(Ident(pname))
val bounds = typeBounds()
val param = atPos(t.pos union bounds.pos) { makeSyntheticTypeParam(pname, bounds) }
placeholderTypes = param :: placeholderTypes
t
}
/* ----------- EXPRESSIONS ------------------------------------------------ */
def condExpr(): Tree = {
if (in.token == LPAREN) {
in.nextToken()
val r = expr()
accept(RPAREN)
r
} else {
accept(LPAREN)
newLiteral(true)
}
}
/* hook for IDE, unlike expression can be stubbed
* don't use for any tree that can be inspected in the parser!
*/
def statement(location: Location): Tree = expr(location) // !!! still needed?
/** {{{
* Expr ::= (Bindings | [`implicit'] Id | `_') `=>' Expr
* | Expr1
* ResultExpr ::= (Bindings | Id `:' CompoundType) `=>' Block
* | Expr1
* Expr1 ::= if `(' Expr `)' {nl} Expr [[semi] else Expr]
* | try (`{' Block `}' | Expr) [catch `{' CaseClauses `}'] [finally Expr]
* | while `(' Expr `)' {nl} Expr
* | do Expr [semi] while `(' Expr `)'
* | for (`(' Enumerators `)' | `{' Enumerators `}') {nl} [yield] Expr
* | throw Expr
* | return [Expr]
* | [SimpleExpr `.'] Id `=' Expr
* | SimpleExpr1 ArgumentExprs `=' Expr
* | PostfixExpr Ascription
* | PostfixExpr match `{' CaseClauses `}'
* Bindings ::= `(' [Binding {`,' Binding}] `)'
* Binding ::= (Id | `_') [`:' Type]
* Ascription ::= `:' CompoundType
* | `:' Annotation {Annotation}
* | `:' `_' `*'
* }}}
*/
def expr(): Tree = expr(Local)
def expr(location: Location): Tree = withPlaceholders(expr0(location), isAny = false)
def expr0(location: Location): Tree = (in.token: @scala.annotation.switch) match {
case IF =>
def parseIf = atPos(in.skipToken()) {
val cond = condExpr()
newLinesOpt()
val thenp = expr()
val elsep = if (in.token == ELSE) { in.nextToken(); expr() }
else literalUnit
If(cond, thenp, elsep)
}
parseIf
case TRY =>
def parseTry = atPos(in.skipToken()) {
val body = in.token match {
case LBRACE => inBracesOrUnit(block())
case LPAREN => inParensOrUnit(expr())
case _ => expr()
}
def catchFromExpr() = List(makeCatchFromExpr(expr()))
val catches: List[CaseDef] =
if (in.token != CATCH) Nil
else {
in.nextToken()
if (in.token != LBRACE) catchFromExpr()
else inBracesOrNil {
if (in.token == CASE) caseClauses()
else catchFromExpr()
}
}
val finalizer = in.token match {
case FINALLY => in.nextToken(); expr()
case _ => EmptyTree
}
Try(body, catches, finalizer)
}
parseTry
case WHILE =>
def parseWhile = {
val start = in.offset
atPos(in.skipToken()) {
val cond = condExpr()
newLinesOpt()
val body = expr()
makeWhile(start, cond, body)
}
}
parseWhile
case DO =>
def parseDo = {
atPos(in.skipToken()) {
val lname: Name = freshTermName(nme.DO_WHILE_PREFIX)
val body = expr()
if (isStatSep) in.nextToken()
accept(WHILE)
val cond = condExpr()
makeDoWhile(lname.toTermName, body, cond)
}
}
parseDo
case FOR =>
val start = in.skipToken()
def parseFor = atPos(start) {
val enums =
if (in.token == LBRACE) inBracesOrNil(enumerators())
else inParensOrNil(enumerators())
newLinesOpt()
if (in.token == YIELD) {
in.nextToken()
gen.mkFor(enums, gen.Yield(expr()))
} else {
gen.mkFor(enums, expr())
}
}
def adjustStart(tree: Tree) =
if (tree.pos.isRange && start < tree.pos.start)
tree setPos tree.pos.withStart(start)
else tree
adjustStart(parseFor)
case RETURN =>
def parseReturn =
atPos(in.skipToken()) {
Return(if (isExprIntro) expr() else literalUnit)
}
parseReturn
case THROW =>
def parseThrow =
atPos(in.skipToken()) {
Throw(expr())
}
parseThrow
case IMPLICIT =>
implicitClosure(in.skipToken(), location)
case _ =>
def parseOther = {
var t = postfixExpr()
if (in.token == EQUALS) {
t match {
case Ident(_) | Select(_, _) | Apply(_, _) =>
t = atPos(t.pos.start, in.skipToken()) { gen.mkAssign(t, expr()) }
case _ =>
}
} else if (in.token == COLON) {
t = stripParens(t)
val colonPos = in.skipToken()
if (in.token == USCORE) {
//todo: need to handle case where USCORE is a wildcard in a type
val uscorePos = in.skipToken()
if (isIdent && in.name == nme.STAR) {
in.nextToken()
t = atPos(t.pos.start, colonPos) {
Typed(t, atPos(uscorePos) { Ident(tpnme.WILDCARD_STAR) })
}
} else {
syntaxErrorOrIncomplete("`*' expected", skipIt = true)
}
} else if (isAnnotation) {
t = (t /: annotations(skipNewLines = false))(makeAnnotated)
} else {
t = atPos(t.pos.start, colonPos) {
val tpt = typeOrInfixType(location)
if (isWildcard(t))
(placeholderParams: @unchecked) match {
case (vd @ ValDef(mods, name, _, _)) :: rest =>
placeholderParams = treeCopy.ValDef(vd, mods, name, tpt.duplicate, EmptyTree) :: rest
}
// this does not correspond to syntax, but is necessary to
// accept closures. We might restrict closures to be between {...} only.
Typed(t, tpt)
}
}
} else if (in.token == MATCH) {
t = atPos(t.pos.start, in.skipToken())(Match(stripParens(t), inBracesOrNil(caseClauses())))
}
// in order to allow anonymous functions as statements (as opposed to expressions) inside
// templates, we have to disambiguate them from self type declarations - bug #1565
// The case still missed is unparenthesized single argument, like "x: Int => x + 1", which
// may be impossible to distinguish from a self-type and so remains an error. (See #1564)
def lhsIsTypedParamList() = t match {
case Parens(xs) if xs.forall(isTypedParam) => true
case _ => false
}
if (in.token == ARROW && (location != InTemplate || lhsIsTypedParamList)) {
t = atPos(t.pos.start, in.skipToken()) {
Function(convertToParams(t), if (location != InBlock) expr() else block())
}
}
stripParens(t)
}
parseOther
}
def isTypedParam(t: Tree) = t.isInstanceOf[Typed]
/** {{{
* Expr ::= implicit Id => Expr
* }}}
*/
def implicitClosure(start: Offset, location: Location): Tree = {
val param0 = convertToParam {
atPos(in.offset) {
Ident(ident()) match {
case expr if in.token == COLON =>
in.nextToken() ; Typed(expr, typeOrInfixType(location))
case expr => expr
}
}
}
val param = copyValDef(param0)(mods = param0.mods | Flags.IMPLICIT)
atPos(start, in.offset) {
accept(ARROW)
Function(List(param), if (location != InBlock) expr() else block())
}
}
/** {{{
* PostfixExpr ::= InfixExpr [Id [nl]]
* InfixExpr ::= PrefixExpr
* | InfixExpr Id [nl] InfixExpr
* }}}
*/
def postfixExpr(): Tree = {
val start = in.offset
val base = opstack
def loop(top: Tree): Tree = if (!isIdent) top else {
pushOpInfo(reduceExprStack(base, top))
newLineOptWhenFollowing(isExprIntroToken)
if (isExprIntro)
prefixExpr() match {
case EmptyTree => reduceExprStack(base, top)
case next => loop(next)
}
else finishPostfixOp(start, base, popOpInfo())
}
reduceExprStack(base, loop(prefixExpr()))
}
/** {{{
* PrefixExpr ::= [`-' | `+' | `~' | `!' | `&'] SimpleExpr
* }}}
*/
def prefixExpr(): Tree = {
if (isUnaryOp) {
atPos(in.offset) {
val name = nme.toUnaryName(rawIdent().toTermName)
if (name == nme.UNARY_- && isNumericLit)
simpleExprRest(literal(isNegated = true), canApply = true)
else
Select(stripParens(simpleExpr()), name)
}
}
else simpleExpr()
}
def xmlLiteral(): Tree
/** {{{
* SimpleExpr ::= new (ClassTemplate | TemplateBody)
* | BlockExpr
* | SimpleExpr1 [`_']
* SimpleExpr1 ::= literal
* | xLiteral
* | Path
* | `(' [Exprs] `)'
* | SimpleExpr `.' Id
* | SimpleExpr TypeArgs
* | SimpleExpr1 ArgumentExprs
* }}}
*/
def simpleExpr(): Tree = {
var canApply = true
val t =
if (isLiteral) literal()
else in.token match {
case XMLSTART =>
xmlLiteral()
case IDENTIFIER | BACKQUOTED_IDENT | THIS | SUPER =>
path(thisOK = true, typeOK = false)
case USCORE =>
freshPlaceholder()
case LPAREN =>
atPos(in.offset)(makeParens(commaSeparated(expr())))
case LBRACE =>
canApply = false
blockExpr()
case NEW =>
canApply = false
val nstart = in.skipToken()
val npos = r2p(nstart, nstart, in.lastOffset)
val tstart = in.offset
val (parents, self, stats) = template()
val cpos = r2p(tstart, tstart, in.lastOffset max tstart)
gen.mkNew(parents, self, stats, npos, cpos)
case _ =>
syntaxErrorOrIncompleteAnd("illegal start of simple expression", skipIt = true)(errorTermTree)
}
simpleExprRest(t, canApply = canApply)
}
def simpleExprRest(t: Tree, canApply: Boolean): Tree = {
if (canApply) newLineOptWhenFollowedBy(LBRACE)
in.token match {
case DOT =>
in.nextToken()
simpleExprRest(selector(stripParens(t)), canApply = true)
case LBRACKET =>
val t1 = stripParens(t)
t1 match {
case Ident(_) | Select(_, _) | Apply(_, _) =>
var app: Tree = t1
while (in.token == LBRACKET)
app = atPos(app.pos.start, in.offset)(TypeApply(app, exprTypeArgs()))
simpleExprRest(app, canApply = true)
case _ =>
t1
}
case LPAREN | LBRACE if (canApply) =>
val app = atPos(t.pos.start, in.offset) {
// look for anonymous function application like (f _)(x) and
// translate to (f _).apply(x), bug #460
val sel = t match {
case Parens(List(Typed(_, _: Function))) =>
Select(stripParens(t), nme.apply)
case _ =>
stripParens(t)
}
Apply(sel, argumentExprs())
}
simpleExprRest(app, canApply = true)
case USCORE =>
atPos(t.pos.start, in.skipToken()) {
Typed(stripParens(t), Function(Nil, EmptyTree))
}
case _ =>
t
}
}
/** {{{
* ArgumentExprs ::= `(' [Exprs] `)'
* | [nl] BlockExpr
* }}}
*/
def argumentExprs(): List[Tree] = {
def args(): List[Tree] = commaSeparated(
if (isIdent) treeInfo.assignmentToMaybeNamedArg(expr()) else expr()
)
in.token match {
case LBRACE => List(blockExpr())
case LPAREN => inParens(if (in.token == RPAREN) Nil else args())
case _ => Nil
}
}
/** A succession of argument lists. */
def multipleArgumentExprs(): List[List[Tree]] = {
if (in.token != LPAREN) Nil
else argumentExprs() :: multipleArgumentExprs()
}
/** {{{
* BlockExpr ::= `{' (CaseClauses | Block) `}'
* }}}
*/
def blockExpr(): Tree = atPos(in.offset) {
inBraces {
if (in.token == CASE) Match(EmptyTree, caseClauses())
else block()
}
}
/** {{{
* Block ::= BlockStatSeq
* }}}
* @note Return tree does not carry position.
*/
def block(): Tree = makeBlock(blockStatSeq())
def caseClause(): CaseDef =
atPos(in.offset)(makeCaseDef(pattern(), guard(), caseBlock()))
/** {{{
* CaseClauses ::= CaseClause {CaseClause}
* CaseClause ::= case Pattern [Guard] `=>' Block
* }}}
*/
def caseClauses(): List[CaseDef] = {
val cases = caseSeparated { caseClause() }
if (cases.isEmpty) // trigger error if there are no cases
accept(CASE)
cases
}
// IDE HOOK (so we can memoize case blocks) // needed?
def caseBlock(): Tree =
atPos(accept(ARROW))(block())
/** {{{
* Guard ::= if PostfixExpr
* }}}
*/
def guard(): Tree =
if (in.token == IF) { in.nextToken(); stripParens(postfixExpr()) }
else EmptyTree
/** {{{
* Enumerators ::= Generator {semi Enumerator}
* Enumerator ::= Generator
* | Guard
* | val Pattern1 `=' Expr
* }}}
*/
def enumerators(): List[Tree] = {
val enums = new ListBuffer[Tree]
enums ++= enumerator(isFirst = true)
while (isStatSep) {
in.nextToken()
enums ++= enumerator(isFirst = false)
}
enums.toList
}
def enumerator(isFirst: Boolean, allowNestedIf: Boolean = true): List[Tree] =
if (in.token == IF && !isFirst) makeFilter(in.offset, guard()) :: Nil
else generator(!isFirst, allowNestedIf)
/** {{{
* Generator ::= Pattern1 (`<-' | `=') Expr [Guard]
* }}}
*/
def generator(eqOK: Boolean, allowNestedIf: Boolean = true): List[Tree] = {
val start = in.offset
val hasVal = in.token == VAL
if (hasVal)
in.nextToken()
val pat = noSeq.pattern1()
val point = in.offset
val hasEq = in.token == EQUALS
if (hasVal) {
if (hasEq) deprecationWarning(in.offset, "val keyword in for comprehension is deprecated")
else syntaxError(in.offset, "val in for comprehension must be followed by assignment")
}
if (hasEq && eqOK) in.nextToken()
else accept(LARROW)
val rhs = expr()
def loop(): List[Tree] =
if (in.token != IF) Nil
else makeFilter(in.offset, guard()) :: loop()
val tail =
if (allowNestedIf) loop()
else Nil
// why max? IDE stress tests have shown that lastOffset could be less than start,
// I guess this happens if instead if a for-expression we sit on a closing paren.
val genPos = r2p(start, point, in.lastOffset max start)
gen.mkGenerator(genPos, pat, hasEq, rhs) :: tail
}
def makeFilter(start: Offset, tree: Tree) = gen.Filter(tree).setPos(r2p(start, tree.pos.point, tree.pos.end))
/* -------- PATTERNS ------------------------------------------- */
/** Methods which implicitly propagate whether the initial call took
* place in a context where sequences are allowed. Formerly, this
* was threaded through methods as boolean seqOK.
*/
trait SeqContextSensitive extends PatternContextSensitive {
// is a sequence pattern _* allowed?
def isSequenceOK: Boolean
// are we in an XML pattern?
def isXML: Boolean = false
def functionArgType(): Tree = argType()
def argType(): Tree = {
val start = in.offset
in.token match {
case USCORE =>
in.nextToken()
if (in.token == SUBTYPE || in.token == SUPERTYPE) wildcardType(start)
else atPos(start) { Bind(tpnme.WILDCARD, EmptyTree) }
case _ =>
typ() match {
case Ident(name: TypeName) if nme.isVariableName(name) =>
atPos(start) { Bind(name, EmptyTree) }
case t => t
}
}
}
/** {{{
* Patterns ::= Pattern { `,' Pattern }
* SeqPatterns ::= SeqPattern { `,' SeqPattern }
* }}}
*/
def patterns(): List[Tree] = commaSeparated(pattern())
/** {{{
* Pattern ::= Pattern1 { `|' Pattern1 }
* SeqPattern ::= SeqPattern1 { `|' SeqPattern1 }
* }}}
*/
def pattern(): Tree = {
val start = in.offset
def loop(): List[Tree] = pattern1() :: {
if (isRawBar) { in.nextToken() ; loop() }
else Nil
}
loop() match {
case pat :: Nil => pat
case xs => atPos(start)(makeAlternative(xs))
}
}
/** {{{
* Pattern1 ::= varid `:' TypePat
* | `_' `:' TypePat
* | Pattern2
* SeqPattern1 ::= varid `:' TypePat
* | `_' `:' TypePat
* | [SeqPattern2]
* }}}
*/
def pattern1(): Tree = pattern2() match {
case p @ Ident(name) if in.token == COLON =>
if (treeInfo.isVarPattern(p))
atPos(p.pos.start, in.skipToken())(Typed(p, compoundType()))
else {
syntaxError(in.offset, "Pattern variables must start with a lower-case letter. (SLS 8.1.1.)")
p
}
case p => p
}
/** {{{
* Pattern2 ::= varid [ @ Pattern3 ]
* | Pattern3
* SeqPattern2 ::= varid [ @ SeqPattern3 ]
* | SeqPattern3
* }}}
*/
def pattern2(): Tree = {
val p = pattern3()
if (in.token != AT) p
else p match {
case Ident(nme.WILDCARD) =>
in.nextToken()
pattern3()
case Ident(name) if treeInfo.isVarPattern(p) =>
in.nextToken()
atPos(p.pos.start) { Bind(name, pattern3()) }
case _ => p
}
}
/** {{{
* Pattern3 ::= SimplePattern
* | SimplePattern {Id [nl] SimplePattern}
* }}}
*/
def pattern3(): Tree = {
val top = simplePattern(badPattern3)
val base = opstack
// See SI-3189, SI-4832 for motivation. Cf SI-3480 for counter-motivation.
def isCloseDelim = in.token match {
case RBRACE => isXML
case RPAREN => !isXML
case _ => false
}
def checkWildStar: Tree = top match {
case Ident(nme.WILDCARD) if isSequenceOK && isRawStar => peekingAhead (
if (isCloseDelim) atPos(top.pos.start, in.prev.offset)(Star(stripParens(top)))
else EmptyTree
)
case _ => EmptyTree
}
def loop(top: Tree): Tree = reducePatternStack(base, top) match {
case next if isIdentExcept(raw.BAR) => pushOpInfo(next) ; loop(simplePattern(badPattern3))
case next => next
}
checkWildStar orElse stripParens(loop(top))
}
def badPattern3(): Tree = {
def isComma = in.token == COMMA
def isDelimiter = in.token == RPAREN || in.token == RBRACE
def isCommaOrDelimiter = isComma || isDelimiter
val (isUnderscore, isStar) = opstack match {
case OpInfo(Ident(nme.WILDCARD), nme.STAR, _, _) :: _ => (true, true)
case OpInfo(_, nme.STAR, _, _) :: _ => (false, true)
case _ => (false, false)
}
def isSeqPatternClose = isUnderscore && isStar && isSequenceOK && isDelimiter
val preamble = "bad simple pattern:"
val subtext = (isUnderscore, isStar, isSequenceOK) match {
case (true, true, true) if isComma => "bad use of _* (a sequence pattern must be the last pattern)"
case (true, true, true) if isDelimiter => "bad brace or paren after _*"
case (true, true, false) if isDelimiter => "bad use of _* (sequence pattern not allowed)"
case (false, true, true) if isDelimiter => "use _* to match a sequence"
case (false, true, _) if isCommaOrDelimiter => "trailing * is not a valid pattern"
case _ => null
}
val msg = if (subtext != null) s"$preamble $subtext" else "illegal start of simple pattern"
// better recovery if don't skip delims of patterns
val skip = !isCommaOrDelimiter || isSeqPatternClose
syntaxErrorOrIncompleteAnd(msg, skip)(errorPatternTree)
}
/** {{{
* SimplePattern ::= varid
* | `_'
* | literal
* | XmlPattern
* | StableId /[TypeArgs]/ [`(' [Patterns] `)']
* | StableId [`(' [Patterns] `)']
* | StableId [`(' [Patterns] `,' [varid `@'] `_' `*' `)']
* | `(' [Patterns] `)'
* }}}
*
* XXX: Hook for IDE
*/
def simplePattern(): Tree = (
// simple diagnostics for this entry point
simplePattern(() => syntaxErrorOrIncompleteAnd("illegal start of simple pattern", skipIt = true)(errorPatternTree))
)
def simplePattern(onError: () => Tree): Tree = {
val start = in.offset
in.token match {
case IDENTIFIER | BACKQUOTED_IDENT | THIS =>
val t = stableId()
in.token match {
case INTLIT | LONGLIT | FLOATLIT | DOUBLELIT =>
t match {
case Ident(nme.MINUS) =>
return literal(isNegated = true, inPattern = true, start = start)
case _ =>
}
case _ =>
}
val typeAppliedTree = in.token match {
case LBRACKET => atPos(start, in.offset)(AppliedTypeTree(convertToTypeId(t), typeArgs()))
case _ => t
}
in.token match {
case LPAREN => atPos(start, in.offset)(Apply(typeAppliedTree, argumentPatterns()))
case _ => typeAppliedTree
}
case USCORE =>
in.nextToken()
atPos(start, start) { Ident(nme.WILDCARD) }
case CHARLIT | INTLIT | LONGLIT | FLOATLIT | DOUBLELIT |
STRINGLIT | INTERPOLATIONID | SYMBOLLIT | TRUE | FALSE | NULL =>
literal(inPattern = true)
case LPAREN =>
atPos(start)(makeParens(noSeq.patterns()))
case XMLSTART =>
xmlLiteralPattern()
case _ =>
onError()
}
}
}
/** The implementation of the context sensitive methods for parsing outside of patterns. */
object outPattern extends PatternContextSensitive {
def argType(): Tree = typ()
def functionArgType(): Tree = paramType(useStartAsPosition = true)
}
/** The implementation for parsing inside of patterns at points where sequences are allowed. */
object seqOK extends SeqContextSensitive {
val isSequenceOK = true
}
/** The implementation for parsing inside of patterns at points where sequences are disallowed. */
object noSeq extends SeqContextSensitive {
val isSequenceOK = false
}
/** For use from xml pattern, where sequence is allowed and encouraged. */
object xmlSeqOK extends SeqContextSensitive {
val isSequenceOK = true
override val isXML = true
}
/** These are default entry points into the pattern context sensitive methods:
* they are all initiated from non-pattern context.
*/
def typ(): Tree = outPattern.typ()
def startInfixType() = outPattern.infixType(InfixMode.FirstOp)
def startAnnotType() = outPattern.annotType()
def exprTypeArgs() = outPattern.typeArgs()
def exprSimpleType() = outPattern.simpleType()
/** Default entry points into some pattern contexts. */
def pattern(): Tree = noSeq.pattern()
def seqPatterns(): List[Tree] = seqOK.patterns()
def xmlSeqPatterns(): List[Tree] = xmlSeqOK.patterns() // Called from xml parser
def argumentPatterns(): List[Tree] = inParens {
if (in.token == RPAREN) Nil
else seqPatterns()
}
def xmlLiteralPattern(): Tree
/* -------- MODIFIERS and ANNOTATIONS ------------------------------------------- */
/** Drop `private` modifier when followed by a qualifier.
* Contract `abstract` and `override` to ABSOVERRIDE
*/
private def normalizeModifers(mods: Modifiers): Modifiers =
if (mods.isPrivate && mods.hasAccessBoundary)
normalizeModifers(mods &~ Flags.PRIVATE)
else if (mods hasAllFlags (Flags.ABSTRACT | Flags.OVERRIDE))
normalizeModifers(mods &~ (Flags.ABSTRACT | Flags.OVERRIDE) | Flags.ABSOVERRIDE)
else
mods
private def addMod(mods: Modifiers, mod: Long, pos: Position): Modifiers = {
if (mods hasFlag mod) syntaxError(in.offset, "repeated modifier", skipIt = false)
in.nextToken()
(mods | mod) withPosition (mod, pos)
}
private def tokenRange(token: TokenData) =
r2p(token.offset, token.offset, token.offset + token.name.length - 1)
/** {{{
* AccessQualifier ::= `[' (Id | this) `]'
* }}}
*/
def accessQualifierOpt(mods: Modifiers): Modifiers = {
var result = mods
if (in.token == LBRACKET) {
in.nextToken()
if (mods.hasAccessBoundary)
syntaxError("duplicate private/protected qualifier", skipIt = false)
result = if (in.token == THIS) { in.nextToken(); mods | Flags.LOCAL }
else Modifiers(mods.flags, identForType())
accept(RBRACKET)
}
result
}
private val flagTokens: Map[Int, Long] = Map(
ABSTRACT -> Flags.ABSTRACT,
FINAL -> Flags.FINAL,
IMPLICIT -> Flags.IMPLICIT,
LAZY -> Flags.LAZY,
OVERRIDE -> Flags.OVERRIDE,
PRIVATE -> Flags.PRIVATE,
PROTECTED -> Flags.PROTECTED,
SEALED -> Flags.SEALED
)
/** {{{
* AccessModifier ::= (private | protected) [AccessQualifier]
* }}}
*/
def accessModifierOpt(): Modifiers = normalizeModifers {
in.token match {
case m @ (PRIVATE | PROTECTED) => in.nextToken() ; accessQualifierOpt(Modifiers(flagTokens(m)))
case _ => NoMods
}
}
/** {{{
* Modifiers ::= {Modifier}
* Modifier ::= LocalModifier
* | AccessModifier
* | override
* }}}
*/
def modifiers(): Modifiers = normalizeModifers {
def loop(mods: Modifiers): Modifiers = in.token match {
case PRIVATE | PROTECTED =>
loop(accessQualifierOpt(addMod(mods, flagTokens(in.token), tokenRange(in))))
case ABSTRACT | FINAL | SEALED | OVERRIDE | IMPLICIT | LAZY =>
loop(addMod(mods, flagTokens(in.token), tokenRange(in)))
case NEWLINE =>
in.nextToken()
loop(mods)
case _ =>
mods
}
loop(NoMods)
}
/** {{{
* LocalModifiers ::= {LocalModifier}
* LocalModifier ::= abstract | final | sealed | implicit | lazy
* }}}
*/
def localModifiers(): Modifiers = {
def loop(mods: Modifiers): Modifiers =
if (isLocalModifier) loop(addMod(mods, flagTokens(in.token), tokenRange(in)))
else mods
loop(NoMods)
}
/** {{{
* Annotations ::= {`@' SimpleType {ArgumentExprs}}
* ConsrAnnotations ::= {`@' SimpleType ArgumentExprs}
* }}}
*/
def annotations(skipNewLines: Boolean): List[Tree] = readAnnots {
val t = annotationExpr()
if (skipNewLines) newLineOpt()
t
}
def constructorAnnotations(): List[Tree] = readAnnots {
atPos(in.offset)(New(exprSimpleType(), List(argumentExprs())))
}
def annotationExpr(): Tree = atPos(in.offset) {
val t = exprSimpleType()
if (in.token == LPAREN) New(t, multipleArgumentExprs())
else New(t, Nil)
}
/* -------- PARAMETERS ------------------------------------------- */
/** {{{
* ParamClauses ::= {ParamClause} [[nl] `(' implicit Params `)']
* ParamClause ::= [nl] `(' [Params] `)'
* Params ::= Param {`,' Param}
* Param ::= {Annotation} Id [`:' ParamType] [`=' Expr]
* ClassParamClauses ::= {ClassParamClause} [[nl] `(' implicit ClassParams `)']
* ClassParamClause ::= [nl] `(' [ClassParams] `)'
* ClassParams ::= ClassParam {`,' ClassParam}
* ClassParam ::= {Annotation} [{Modifier} (`val' | `var')] Id [`:' ParamType] [`=' Expr]
* }}}
*/
def paramClauses(owner: Name, contextBounds: List[Tree], ofCaseClass: Boolean): List[List[ValDef]] = {
var implicitmod = 0
var caseParam = ofCaseClass
def paramClause(): List[ValDef] = {
if (in.token == RPAREN)
return Nil
if (in.token == IMPLICIT) {
in.nextToken()
implicitmod = Flags.IMPLICIT
}
commaSeparated(param(owner, implicitmod, caseParam ))
}
val vds = new ListBuffer[List[ValDef]]
val start = in.offset
newLineOptWhenFollowedBy(LPAREN)
if (ofCaseClass && in.token != LPAREN)
syntaxError(in.lastOffset, "case classes without a parameter list are not allowed;\n"+
"use either case objects or case classes with an explicit `()' as a parameter list.")
while (implicitmod == 0 && in.token == LPAREN) {
in.nextToken()
vds += paramClause()
accept(RPAREN)
caseParam = false
newLineOptWhenFollowedBy(LPAREN)
}
val result = vds.toList
if (owner == nme.CONSTRUCTOR && (result.isEmpty || (result.head take 1 exists (_.mods.isImplicit)))) {
in.token match {
case LBRACKET => syntaxError(in.offset, "no type parameters allowed here", skipIt = false)
case EOF => incompleteInputError("auxiliary constructor needs non-implicit parameter list")
case _ => syntaxError(start, "auxiliary constructor needs non-implicit parameter list", skipIt = false)
}
}
addEvidenceParams(owner, result, contextBounds)
}
/** {{{
* ParamType ::= Type | `=>' Type | Type `*'
* }}}
*/
def paramType(): Tree = paramType(useStartAsPosition = false)
def paramType(useStartAsPosition: Boolean): Tree = {
val start = in.offset
in.token match {
case ARROW =>
in.nextToken()
atPos(start)(byNameApplication(typ()))
case _ =>
val t = typ()
if (isRawStar) {
in.nextToken()
if (useStartAsPosition) atPos(start)(repeatedApplication(t))
else atPos(t.pos.start, t.pos.point)(repeatedApplication(t))
}
else t
}
}
def param(owner: Name, implicitmod: Int, caseParam: Boolean): ValDef = {
val start = in.offset
val annots = annotations(skipNewLines = false)
var mods = Modifiers(Flags.PARAM)
if (owner.isTypeName) {
mods = modifiers() | Flags.PARAMACCESSOR
if (mods.isLazy) syntaxError("lazy modifier not allowed here. Use call-by-name parameters instead", skipIt = false)
in.token match {
case v @ (VAL | VAR) =>
mods = mods withPosition (in.token.toLong, tokenRange(in))
if (v == VAR) mods |= Flags.MUTABLE
in.nextToken()
case _ =>
if (mods.flags != Flags.PARAMACCESSOR) accept(VAL)
if (!caseParam) mods |= Flags.PrivateLocal
}
if (caseParam) mods |= Flags.CASEACCESSOR
}
val nameOffset = in.offset
val name = ident()
var bynamemod = 0
val tpt =
if ((settings.YmethodInfer && !owner.isTypeName) && in.token != COLON) {
TypeTree()
} else { // XX-METHOD-INFER
accept(COLON)
if (in.token == ARROW) {
if (owner.isTypeName && !mods.isLocalToThis)
syntaxError(
in.offset,
(if (mods.isMutable) "`var'" else "`val'") +
" parameters may not be call-by-name", skipIt = false)
else if (implicitmod != 0)
syntaxError(
in.offset,
"implicit parameters may not be call-by-name", skipIt = false)
else bynamemod = Flags.BYNAMEPARAM
}
paramType()
}
val default =
if (in.token == EQUALS) {
in.nextToken()
mods |= Flags.DEFAULTPARAM
expr()
} else EmptyTree
atPos(start, if (name == nme.ERROR) start else nameOffset) {
ValDef((mods | implicitmod.toLong | bynamemod) withAnnotations annots, name.toTermName, tpt, default)
}
}
/** {{{
* TypeParamClauseOpt ::= [TypeParamClause]
* TypeParamClause ::= `[' VariantTypeParam {`,' VariantTypeParam} `]']
* VariantTypeParam ::= {Annotation} [`+' | `-'] TypeParam
* FunTypeParamClauseOpt ::= [FunTypeParamClause]
* FunTypeParamClause ::= `[' TypeParam {`,' TypeParam} `]']
* TypeParam ::= Id TypeParamClauseOpt TypeBounds {<% Type} {":" Type}
* }}}
*/
def typeParamClauseOpt(owner: Name, contextBoundBuf: ListBuffer[Tree]): List[TypeDef] = {
def typeParam(ms: Modifiers): TypeDef = {
var mods = ms | Flags.PARAM
val start = in.offset
if (owner.isTypeName && isIdent) {
if (in.name == raw.PLUS) {
in.nextToken()
mods |= Flags.COVARIANT
} else if (in.name == raw.MINUS) {
in.nextToken()
mods |= Flags.CONTRAVARIANT
}
}
val nameOffset = in.offset
// TODO AM: freshTermName(o2p(in.skipToken()), "_$$"), will need to update test suite
val pname: TypeName = wildcardOrIdent().toTypeName
val param = atPos(start, nameOffset) {
val tparams = typeParamClauseOpt(pname, null) // @M TODO null --> no higher-order context bounds for now
TypeDef(mods, pname, tparams, typeBounds())
}
if (contextBoundBuf ne null) {
while (in.token == VIEWBOUND) {
val msg = "Use an implicit parameter instead.\nExample: Instead of `def f[A <% Int](a: A)` use `def f[A](a: A)(implicit ev: A => Int)`."
if (settings.future)
deprecationWarning(in.offset, s"View bounds are deprecated. $msg")
contextBoundBuf += atPos(in.skipToken())(makeFunctionTypeTree(List(Ident(pname)), typ()))
}
while (in.token == COLON) {
contextBoundBuf += atPos(in.skipToken()) {
AppliedTypeTree(typ(), List(Ident(pname)))
}
}
}
param
}
newLineOptWhenFollowedBy(LBRACKET)
if (in.token == LBRACKET) inBrackets(commaSeparated(typeParam(NoMods withAnnotations annotations(skipNewLines = true))))
else Nil
}
/** {{{
* TypeBounds ::= [`>:' Type] [`<:' Type]
* }}}
*/
def typeBounds(): TypeBoundsTree = {
val lo = bound(SUPERTYPE)
val hi = bound(SUBTYPE)
val t = TypeBoundsTree(lo, hi)
val defined = List(t.hi, t.lo) filter (_.pos.isDefined)
if (defined.nonEmpty)
t setPos wrappingPos(defined)
else
t setPos o2p(in.offset)
}
def bound(tok: Token): Tree = if (in.token == tok) { in.nextToken(); typ() } else EmptyTree
/* -------- DEFS ------------------------------------------- */
/** {{{
* Import ::= import ImportExpr {`,' ImportExpr}
* }}}
*/
def importClause(): List[Tree] = {
val offset = accept(IMPORT)
commaSeparated(importExpr()) match {
case Nil => Nil
case t :: rest =>
// The first import should start at the position of the keyword.
t.setPos(t.pos.withStart(offset))
t :: rest
}
}
/** {{{
* ImportExpr ::= StableId `.' (Id | `_' | ImportSelectors)
* }}}
*/
def importExpr(): Tree = {
val start = in.offset
def thisDotted(name: TypeName) = {
in.nextToken()
val t = atPos(start)(This(name))
accept(DOT)
val result = selector(t)
accept(DOT)
result
}
/* Walks down import `foo.bar.baz.{ ... }` until it ends at a
* an underscore, a left brace, or an undotted identifier.
*/
def loop(expr: Tree): Tree = {
expr setPos expr.pos.makeTransparent
val selectors: List[ImportSelector] = in.token match {
case USCORE => List(importSelector()) // import foo.bar._;
case LBRACE => importSelectors() // import foo.bar.{ x, y, z }
case _ =>
val nameOffset = in.offset
val name = ident()
if (in.token == DOT) {
// import foo.bar.ident.<unknown> and so create a select node and recurse.
val t = atPos(start, if (name == nme.ERROR) in.offset else nameOffset)(Select(expr, name))
in.nextToken()
return loop(t)
}
// import foo.bar.Baz;
else List(makeImportSelector(name, nameOffset))
}
// reaching here means we're done walking.
atPos(start)(Import(expr, selectors))
}
loop(in.token match {
case THIS => thisDotted(tpnme.EMPTY)
case _ =>
val id = atPos(start)(Ident(ident()))
accept(DOT)
if (in.token == THIS) thisDotted(id.name.toTypeName)
else id
})
}
/** {{{
* ImportSelectors ::= `{' {ImportSelector `,'} (ImportSelector | `_') `}'
* }}}
*/
def importSelectors(): List[ImportSelector] = {
val selectors = inBracesOrNil(commaSeparated(importSelector()))
selectors.init foreach {
case ImportSelector(nme.WILDCARD, pos, _, _) => syntaxError(pos, "Wildcard import must be in last position")
case _ => ()
}
selectors
}
def wildcardOrIdent() = {
if (in.token == USCORE) { in.nextToken() ; nme.WILDCARD }
else ident()
}
/** {{{
* ImportSelector ::= Id [`=>' Id | `=>' `_']
* }}}
*/
def importSelector(): ImportSelector = {
val start = in.offset
val name = wildcardOrIdent()
var renameOffset = -1
val rename = in.token match {
case ARROW =>
in.nextToken()
renameOffset = in.offset
wildcardOrIdent()
case _ if name == nme.WILDCARD => null
case _ =>
renameOffset = start
name
}
ImportSelector(name, start, rename, renameOffset)
}
/** {{{
* Def ::= val PatDef
* | var PatDef
* | def FunDef
* | type [nl] TypeDef
* | TmplDef
* Dcl ::= val PatDcl
* | var PatDcl
* | def FunDcl
* | type [nl] TypeDcl
* }}}
*/
def defOrDcl(pos: Offset, mods: Modifiers): List[Tree] = {
if (mods.isLazy && in.token != VAL)
syntaxError("lazy not allowed here. Only vals can be lazy", skipIt = false)
in.token match {
case VAL =>
patDefOrDcl(pos, mods withPosition(VAL, tokenRange(in)))
case VAR =>
patDefOrDcl(pos, (mods | Flags.MUTABLE) withPosition (VAR, tokenRange(in)))
case DEF =>
List(funDefOrDcl(pos, mods withPosition(DEF, tokenRange(in))))
case TYPE =>
List(typeDefOrDcl(pos, mods withPosition(TYPE, tokenRange(in))))
case _ =>
List(tmplDef(pos, mods))
}
}
private def caseAwareTokenOffset = if (in.token == CASECLASS || in.token == CASEOBJECT) in.prev.offset else in.offset
def nonLocalDefOrDcl : List[Tree] = {
val annots = annotations(skipNewLines = true)
defOrDcl(caseAwareTokenOffset, modifiers() withAnnotations annots)
}
/** {{{
* PatDef ::= Pattern2 {`,' Pattern2} [`:' Type] `=' Expr
* ValDcl ::= Id {`,' Id} `:' Type
* VarDef ::= PatDef | Id {`,' Id} `:' Type `=' `_'
* }}}
*/
def patDefOrDcl(pos : Int, mods: Modifiers): List[Tree] = {
var newmods = mods
in.nextToken()
val lhs = commaSeparated(stripParens(noSeq.pattern2()))
val tp = typedOpt()
val rhs =
if (tp.isEmpty || in.token == EQUALS) {
accept(EQUALS)
if (!tp.isEmpty && newmods.isMutable &&
(lhs.toList forall (_.isInstanceOf[Ident])) && in.token == USCORE) {
in.nextToken()
newmods = newmods | Flags.DEFAULTINIT
EmptyTree
} else {
expr()
}
} else {
newmods = newmods | Flags.DEFERRED
EmptyTree
}
def mkDefs(p: Tree, tp: Tree, rhs: Tree): List[Tree] = {
val trees = {
val pat = if (tp.isEmpty) p else Typed(p, tp) setPos (p.pos union tp.pos)
makePatDef(newmods, pat, rhs)
}
if (newmods.isDeferred) {
trees match {
case List(ValDef(_, _, _, EmptyTree)) =>
if (mods.isLazy) syntaxError(p.pos, "lazy values may not be abstract", skipIt = false)
case _ => syntaxError(p.pos, "pattern definition may not be abstract", skipIt = false)
}
}
trees
}
val trees = (lhs.toList.init flatMap (mkDefs(_, tp.duplicate, rhs.duplicate))) ::: mkDefs(lhs.last, tp, rhs)
val hd = trees.head
hd setPos hd.pos.withStart(pos)
ensureNonOverlapping(hd, trees.tail)
trees
}
/** {{{
* VarDef ::= PatDef
* | Id {`,' Id} `:' Type `=' `_'
* VarDcl ::= Id {`,' Id} `:' Type
* }}}
def varDefOrDcl(mods: Modifiers): List[Tree] = {
var newmods = mods | Flags.MUTABLE
val lhs = new ListBuffer[(Int, Name)]
do {
in.nextToken()
lhs += (in.offset, ident())
} while (in.token == COMMA)
val tp = typedOpt()
val rhs = if (tp.isEmpty || in.token == EQUALS) {
accept(EQUALS)
if (!tp.isEmpty && in.token == USCORE) {
in.nextToken()
EmptyTree
} else {
expr()
}
} else {
newmods = newmods | Flags.DEFERRED
EmptyTree
}
}
*/
/** {{{
* FunDef ::= FunSig [`:' Type] `=' [`macro'] Expr
* | FunSig [nl] `{' Block `}'
* | `this' ParamClause ParamClauses
* (`=' ConstrExpr | [nl] ConstrBlock)
* FunDcl ::= FunSig [`:' Type]
* FunSig ::= id [FunTypeParamClause] ParamClauses
* }}}
*/
def funDefOrDcl(start : Int, mods: Modifiers): Tree = {
in.nextToken()
if (in.token == THIS) {
atPos(start, in.skipToken()) {
val vparamss = paramClauses(nme.CONSTRUCTOR, classContextBounds map (_.duplicate), ofCaseClass = false)
newLineOptWhenFollowedBy(LBRACE)
val rhs = in.token match {
case LBRACE => atPos(in.offset) { constrBlock(vparamss) }
case _ => accept(EQUALS) ; atPos(in.offset) { constrExpr(vparamss) }
}
DefDef(mods, nme.CONSTRUCTOR, List(), vparamss, TypeTree(), rhs)
}
}
else {
val nameOffset = in.offset
val name = identOrMacro()
funDefRest(start, nameOffset, mods, name)
}
}
def funDefRest(start: Offset, nameOffset: Offset, mods: Modifiers, name: Name): Tree = {
val result = atPos(start, if (name.toTermName == nme.ERROR) start else nameOffset) {
var newmods = mods
// contextBoundBuf is for context bounded type parameters of the form
// [T : B] or [T : => B]; it contains the equivalent implicit parameter type,
// i.e. (B[T] or T => B)
val contextBoundBuf = new ListBuffer[Tree]
val tparams = typeParamClauseOpt(name, contextBoundBuf)
val vparamss = paramClauses(name, contextBoundBuf.toList, ofCaseClass = false)
newLineOptWhenFollowedBy(LBRACE)
var restype = fromWithinReturnType(typedOpt())
val rhs =
if (isStatSep || in.token == RBRACE) {
if (restype.isEmpty) {
if (settings.future)
deprecationWarning(in.lastOffset, s"Procedure syntax is deprecated. Convert procedure `$name` to method by adding `: Unit`.")
restype = scalaUnitConstr
}
newmods |= Flags.DEFERRED
EmptyTree
} else if (restype.isEmpty && in.token == LBRACE) {
if (settings.future)
deprecationWarning(in.offset, s"Procedure syntax is deprecated. Convert procedure `$name` to method by adding `: Unit =`.")
restype = scalaUnitConstr
blockExpr()
} else {
if (in.token == EQUALS) {
in.nextTokenAllow(nme.MACROkw)
if (isMacro) {
in.nextToken()
newmods |= Flags.MACRO
}
} else {
accept(EQUALS)
}
expr()
}
DefDef(newmods, name.toTermName, tparams, vparamss, restype, rhs)
}
signalParseProgress(result.pos)
result
}
/** {{{
* ConstrExpr ::= SelfInvocation
* | ConstrBlock
* }}}
*/
def constrExpr(vparamss: List[List[ValDef]]): Tree =
if (in.token == LBRACE) constrBlock(vparamss)
else Block(selfInvocation(vparamss) :: Nil, literalUnit)
/** {{{
* SelfInvocation ::= this ArgumentExprs {ArgumentExprs}
* }}}
*/
def selfInvocation(vparamss: List[List[ValDef]]): Tree =
atPos(accept(THIS)) {
newLineOptWhenFollowedBy(LBRACE)
var t = Apply(Ident(nme.CONSTRUCTOR), argumentExprs())
newLineOptWhenFollowedBy(LBRACE)
while (in.token == LPAREN || in.token == LBRACE) {
t = Apply(t, argumentExprs())
newLineOptWhenFollowedBy(LBRACE)
}
if (classContextBounds.isEmpty) t
else Apply(t, vparamss.last.map(vp => Ident(vp.name)))
}
/** {{{
* ConstrBlock ::= `{' SelfInvocation {semi BlockStat} `}'
* }}}
*/
def constrBlock(vparamss: List[List[ValDef]]): Tree =
atPos(in.skipToken()) {
val stats = selfInvocation(vparamss) :: {
if (isStatSep) { in.nextToken(); blockStatSeq() }
else Nil
}
accept(RBRACE)
Block(stats, literalUnit)
}
/** {{{
* TypeDef ::= type Id [TypeParamClause] `=' Type
* | FunSig `=' Expr
* TypeDcl ::= type Id [TypeParamClause] TypeBounds
* }}}
*/
def typeDefOrDcl(start: Offset, mods: Modifiers): Tree = {
in.nextToken()
newLinesOpt()
atPos(start, in.offset) {
val name = identForType()
// @M! a type alias as well as an abstract type may declare type parameters
val tparams = typeParamClauseOpt(name, null)
in.token match {
case EQUALS =>
in.nextToken()
TypeDef(mods, name, tparams, typ())
case t if t == SUPERTYPE || t == SUBTYPE || t == COMMA || t == RBRACE || isStatSep(t) =>
TypeDef(mods | Flags.DEFERRED, name, tparams, typeBounds())
case _ =>
syntaxErrorOrIncompleteAnd("`=', `>:', or `<:' expected", skipIt = true)(EmptyTree)
}
}
}
/** Hook for IDE, for top-level classes/objects. */
def topLevelTmplDef: Tree = {
val annots = annotations(skipNewLines = true)
val pos = caseAwareTokenOffset
val mods = modifiers() withAnnotations annots
tmplDef(pos, mods)
}
/** {{{
* TmplDef ::= [case] class ClassDef
* | [case] object ObjectDef
* | [override] trait TraitDef
* }}}
*/
def tmplDef(pos: Offset, mods: Modifiers): Tree = {
if (mods.isLazy) syntaxError("classes cannot be lazy", skipIt = false)
in.token match {
case TRAIT =>
classDef(pos, (mods | Flags.TRAIT | Flags.ABSTRACT) withPosition (Flags.TRAIT, tokenRange(in)))
case CLASS =>
classDef(pos, mods)
case CASECLASS =>
classDef(pos, (mods | Flags.CASE) withPosition (Flags.CASE, tokenRange(in.prev /*scanner skips on 'case' to 'class', thus take prev*/)))
case OBJECT =>
objectDef(pos, mods)
case CASEOBJECT =>
objectDef(pos, (mods | Flags.CASE) withPosition (Flags.CASE, tokenRange(in.prev /*scanner skips on 'case' to 'object', thus take prev*/)))
case _ =>
syntaxErrorOrIncompleteAnd("expected start of definition", skipIt = true)(EmptyTree)
}
}
/** {{{
* ClassDef ::= Id [TypeParamClause] {Annotation}
* [AccessModifier] ClassParamClauses RequiresTypeOpt ClassTemplateOpt
* TraitDef ::= Id [TypeParamClause] RequiresTypeOpt TraitTemplateOpt
* }}}
*/
def classDef(start: Offset, mods: Modifiers): ClassDef = {
in.nextToken()
val nameOffset = in.offset
val name = identForType()
atPos(start, if (name == tpnme.ERROR) start else nameOffset) {
savingClassContextBounds {
val contextBoundBuf = new ListBuffer[Tree]
val tparams = typeParamClauseOpt(name, contextBoundBuf)
classContextBounds = contextBoundBuf.toList
val tstart = (in.offset :: classContextBounds.map(_.pos.start)).min
if (!classContextBounds.isEmpty && mods.isTrait) {
val viewBoundsExist = if (settings.future) "" else " nor view bounds `<% ...'"
syntaxError(s"traits cannot have type parameters with context bounds `: ...'$viewBoundsExist", skipIt = false)
classContextBounds = List()
}
val constrAnnots = if (!mods.isTrait) constructorAnnotations() else Nil
val (constrMods, vparamss) =
if (mods.isTrait) (Modifiers(Flags.TRAIT), List())
else (accessModifierOpt(), paramClauses(name, classContextBounds, ofCaseClass = mods.isCase))
var mods1 = mods
if (mods.isTrait) {
if (settings.YvirtClasses && in.token == SUBTYPE) mods1 |= Flags.DEFERRED
} else if (in.token == SUBTYPE) {
syntaxError("classes are not allowed to be virtual", skipIt = false)
}
val template = templateOpt(mods1, name, constrMods withAnnotations constrAnnots, vparamss, tstart)
val result = gen.mkClassDef(mods1, name, tparams, template)
// Context bounds generate implicit parameters (part of the template) with types
// from tparams: we need to ensure these don't overlap
if (!classContextBounds.isEmpty)
ensureNonOverlapping(template, tparams)
result
}
}
}
/** {{{
* ObjectDef ::= Id ClassTemplateOpt
* }}}
*/
def objectDef(start: Offset, mods: Modifiers): ModuleDef = {
in.nextToken()
val nameOffset = in.offset
val name = ident()
val tstart = in.offset
atPos(start, if (name == nme.ERROR) start else nameOffset) {
val mods1 = if (in.token == SUBTYPE) mods | Flags.DEFERRED else mods
val template = templateOpt(mods1, name, NoMods, Nil, tstart)
ModuleDef(mods1, name.toTermName, template)
}
}
/** Create a tree representing a package object, converting
* {{{
* package object foo { ... }
* }}}
* to
* {{{
* package foo {
* object `package` { ... }
* }
* }}}
*/
def packageObjectDef(start: Offset): PackageDef = {
val defn = objectDef(in.offset, NoMods)
val pidPos = o2p(defn.pos.startOrPoint)
val pkgPos = r2p(start, pidPos.point)
gen.mkPackageObject(defn, pidPos, pkgPos)
}
def packageOrPackageObject(start: Offset): Tree = (
if (in.token == OBJECT)
joinComment(packageObjectDef(start) :: Nil).head
else {
in.flushDoc
makePackaging(start, pkgQualId(), inBracesOrNil(topStatSeq()))
}
)
// TODO - eliminate this and use "def packageObjectDef" (see call site of this
// method for small elaboration.)
def makePackageObject(start: Offset, objDef: ModuleDef): PackageDef = objDef match {
case ModuleDef(mods, name, impl) =>
makePackaging(
start, atPos(o2p(objDef.pos.start)){ Ident(name) }, List(ModuleDef(mods, nme.PACKAGEkw, impl)))
}
/** {{{
* ClassParents ::= AnnotType {`(' [Exprs] `)'} {with AnnotType}
* TraitParents ::= AnnotType {with AnnotType}
* }}}
*/
def templateParents(): List[Tree] = {
val parents = new ListBuffer[Tree]
def readAppliedParent() = {
val start = in.offset
val parent = startAnnotType()
parents += (in.token match {
case LPAREN => atPos(start)((parent /: multipleArgumentExprs())(Apply.apply))
case _ => parent
})
}
readAppliedParent()
while (in.token == WITH) { in.nextToken(); readAppliedParent() }
parents.toList
}
/** {{{
* ClassTemplate ::= [EarlyDefs with] ClassParents [TemplateBody]
* TraitTemplate ::= [EarlyDefs with] TraitParents [TemplateBody]
* EarlyDefs ::= `{' [EarlyDef {semi EarlyDef}] `}'
* EarlyDef ::= Annotations Modifiers PatDef
* }}}
*/
def template(): (List[Tree], ValDef, List[Tree]) = {
newLineOptWhenFollowedBy(LBRACE)
if (in.token == LBRACE) {
// @S: pre template body cannot stub like post body can!
val (self, body) = templateBody(isPre = true)
if (in.token == WITH && (self eq noSelfType)) {
val earlyDefs: List[Tree] = body.map(ensureEarlyDef).filter(_.nonEmpty)
in.nextToken()
val parents = templateParents()
val (self1, body1) = templateBodyOpt(parenMeansSyntaxError = false)
(parents, self1, earlyDefs ::: body1)
} else {
(List(), self, body)
}
} else {
val parents = templateParents()
val (self, body) = templateBodyOpt(parenMeansSyntaxError = false)
(parents, self, body)
}
}
def ensureEarlyDef(tree: Tree): Tree = tree match {
case vdef @ ValDef(mods, _, _, _) if !mods.isDeferred =>
copyValDef(vdef)(mods = mods | Flags.PRESUPER)
case tdef @ TypeDef(mods, name, tparams, rhs) =>
deprecationWarning(tdef.pos.point, "early type members are deprecated. Move them to the regular body: the semantics are the same.")
treeCopy.TypeDef(tdef, mods | Flags.PRESUPER, name, tparams, rhs)
case docdef @ DocDef(comm, rhs) =>
treeCopy.DocDef(docdef, comm, rhs)
case stat if !stat.isEmpty =>
syntaxError(stat.pos, "only concrete field definitions allowed in early object initialization section", skipIt = false)
EmptyTree
case _ =>
EmptyTree
}
/** {{{
* ClassTemplateOpt ::= `extends' ClassTemplate | [[`extends'] TemplateBody]
* TraitTemplateOpt ::= TraitExtends TraitTemplate | [[`extends'] TemplateBody] | `<:' TemplateBody
* TraitExtends ::= `extends' | `<:'
* }}}
*/
def templateOpt(mods: Modifiers, name: Name, constrMods: Modifiers, vparamss: List[List[ValDef]], tstart: Offset): Template = {
val (parents, self, body) = (
if (in.token == EXTENDS || in.token == SUBTYPE && mods.isTrait) {
in.nextToken()
template()
}
else {
newLineOptWhenFollowedBy(LBRACE)
val (self, body) = templateBodyOpt(parenMeansSyntaxError = mods.isTrait || name.isTermName)
(List(), self, body)
}
)
def anyvalConstructor() = (
// Not a well-formed constructor, has to be finished later - see note
// regarding AnyVal constructor in AddInterfaces.
DefDef(NoMods, nme.CONSTRUCTOR, Nil, ListOfNil, TypeTree(), Block(Nil, literalUnit))
)
val parentPos = o2p(in.offset)
val tstart1 = if (body.isEmpty && in.lastOffset < tstart) in.lastOffset else tstart
atPos(tstart1) {
// Exclude only the 9 primitives plus AnyVal.
if (inScalaRootPackage && ScalaValueClassNames.contains(name))
Template(parents, self, anyvalConstructor :: body)
else
gen.mkTemplate(gen.mkParents(mods, parents, parentPos),
self, constrMods, vparamss, body, o2p(tstart))
}
}
/* -------- TEMPLATES ------------------------------------------- */
/** {{{
* TemplateBody ::= [nl] `{' TemplateStatSeq `}'
* }}}
* @param isPre specifies whether in early initializer (true) or not (false)
*/
def templateBody(isPre: Boolean) = inBraces(templateStatSeq(isPre = isPre)) match {
case (self, Nil) => (self, EmptyTree.asList)
case result => result
}
def templateBodyOpt(parenMeansSyntaxError: Boolean): (ValDef, List[Tree]) = {
newLineOptWhenFollowedBy(LBRACE)
if (in.token == LBRACE) {
templateBody(isPre = false)
} else {
if (in.token == LPAREN) {
if (parenMeansSyntaxError) syntaxError(s"traits or objects may not have parameters", skipIt = true)
else abort("unexpected opening parenthesis")
}
(noSelfType, List())
}
}
/** {{{
* Refinement ::= [nl] `{' RefineStat {semi RefineStat} `}'
* }}}
*/
def refinement(): List[Tree] = inBraces(refineStatSeq())
/* -------- STATSEQS ------------------------------------------- */
/** Create a tree representing a packaging. */
def makePackaging(start: Offset, pkg: Tree, stats: List[Tree]): PackageDef = pkg match {
case x: RefTree => atPos(start, pkg.pos.point)(PackageDef(x, stats))
}
def makeEmptyPackage(start: Offset, stats: List[Tree]): PackageDef = (
makePackaging(start, atPos(start, start, start)(Ident(nme.EMPTY_PACKAGE_NAME)), stats)
)
def statSeq(stat: PartialFunction[Token, List[Tree]], errorMsg: String = "illegal start of definition"): List[Tree] = {
val stats = new ListBuffer[Tree]
def default(tok: Token) =
if (isStatSep) Nil
else syntaxErrorOrIncompleteAnd(errorMsg, skipIt = true)(Nil)
while (!isStatSeqEnd) {
stats ++= stat.applyOrElse(in.token, default)
acceptStatSepOpt()
}
stats.toList
}
/** {{{
* TopStatSeq ::= TopStat {semi TopStat}
* TopStat ::= Annotations Modifiers TmplDef
* | Packaging
* | package object objectDef
* | Import
* |
* }}}
*/
def topStatSeq(): List[Tree] = statSeq(topStat, errorMsg = "expected class or object definition")
def topStat: PartialFunction[Token, List[Tree]] = {
case PACKAGE =>
packageOrPackageObject(in.skipToken()) :: Nil
case IMPORT =>
in.flushDoc
importClause()
case _ if isAnnotation || isTemplateIntro || isModifier =>
joinComment(topLevelTmplDef :: Nil)
}
/** {{{
* TemplateStatSeq ::= [id [`:' Type] `=>'] TemplateStats
* }}}
* @param isPre specifies whether in early initializer (true) or not (false)
*/
def templateStatSeq(isPre : Boolean): (ValDef, List[Tree]) = checkNoEscapingPlaceholders {
var self: ValDef = noSelfType
var firstOpt: Option[Tree] = None
if (isExprIntro) {
in.flushDoc
val first = expr(InTemplate) // @S: first statement is potentially converted so cannot be stubbed.
if (in.token == ARROW) {
first match {
case Typed(tree @ This(tpnme.EMPTY), tpt) =>
self = atPos(tree.pos union tpt.pos) { makeSelfDef(nme.WILDCARD, tpt) }
case _ =>
convertToParam(first) match {
case tree @ ValDef(_, name, tpt, EmptyTree) if (name != nme.ERROR) =>
self = atPos(tree.pos union tpt.pos) { makeSelfDef(name, tpt) }
case _ =>
}
}
in.nextToken()
} else {
firstOpt = Some(first)
acceptStatSepOpt()
}
}
(self, firstOpt ++: templateStats())
}
/** {{{
* TemplateStats ::= TemplateStat {semi TemplateStat}
* TemplateStat ::= Import
* | Annotations Modifiers Def
* | Annotations Modifiers Dcl
* | Expr1
* | super ArgumentExprs {ArgumentExprs}
* |
* }}}
*/
def templateStats(): List[Tree] = statSeq(templateStat)
def templateStat: PartialFunction[Token, List[Tree]] = {
case IMPORT =>
in.flushDoc
importClause()
case _ if isDefIntro || isModifier || isAnnotation =>
joinComment(nonLocalDefOrDcl)
case _ if isExprIntro =>
in.flushDoc
statement(InTemplate) :: Nil
}
def templateOrTopStatSeq(): List[Tree] = statSeq(templateStat.orElse(topStat))
/** {{{
* RefineStatSeq ::= RefineStat {semi RefineStat}
* RefineStat ::= Dcl
* | type TypeDef
* |
* }}}
*/
def refineStatSeq(): List[Tree] = checkNoEscapingPlaceholders {
val stats = new ListBuffer[Tree]
while (!isStatSeqEnd) {
stats ++= refineStat()
if (in.token != RBRACE) acceptStatSep()
}
stats.toList
}
def refineStat(): List[Tree] =
if (isDclIntro) { // don't IDE hook
joinComment(defOrDcl(in.offset, NoMods))
} else if (!isStatSep) {
syntaxErrorOrIncomplete(
"illegal start of declaration"+
(if (inFunReturnType) " (possible cause: missing `=' in front of current method body)"
else ""), skipIt = true)
Nil
} else Nil
/** overridable IDE hook for local definitions of blockStatSeq
* Here's an idea how to fill in start and end positions.
def localDef : List[Tree] = {
atEndPos {
atStartPos(in.offset) {
val annots = annotations(skipNewLines = true)
val mods = localModifiers() withAnnotations annots
if (!(mods hasFlag ~(Flags.IMPLICIT | Flags.LAZY))) defOrDcl(mods)
else List(tmplDef(mods))
}
} (in.offset)
}
*/
def localDef(implicitMod: Int): List[Tree] = {
val annots = annotations(skipNewLines = true)
val pos = in.offset
val mods = (localModifiers() | implicitMod.toLong) withAnnotations annots
val defs =
if (!(mods hasFlag ~(Flags.IMPLICIT | Flags.LAZY))) defOrDcl(pos, mods)
else List(tmplDef(pos, mods))
in.token match {
case RBRACE | CASE => defs :+ setInPos(literalUnit)
case _ => defs
}
}
/** {{{
* BlockStatSeq ::= { BlockStat semi } [ResultExpr]
* BlockStat ::= Import
* | Annotations [implicit] [lazy] Def
* | Annotations LocalModifiers TmplDef
* | Expr1
* |
* }}}
*/
def blockStatSeq(): List[Tree] = checkNoEscapingPlaceholders {
val stats = new ListBuffer[Tree]
while (!isStatSeqEnd && !isCaseDefEnd) {
if (in.token == IMPORT) {
stats ++= importClause()
acceptStatSepOpt()
}
else if (isDefIntro || isLocalModifier || isAnnotation) {
if (in.token == IMPLICIT) {
val start = in.skipToken()
if (isIdent) stats += implicitClosure(start, InBlock)
else stats ++= localDef(Flags.IMPLICIT)
} else {
stats ++= localDef(0)
}
acceptStatSepOpt()
}
else if (isExprIntro) {
stats += statement(InBlock)
if (!isCaseDefEnd) acceptStatSep()
}
else if (isStatSep) {
in.nextToken()
}
else {
val addendum = if (isModifier) " (no modifiers allowed here)" else ""
syntaxErrorOrIncomplete("illegal start of statement" + addendum, skipIt = true)
}
}
stats.toList
}
/** {{{
* CompilationUnit ::= {package QualId semi} TopStatSeq
* }}}
*/
def compilationUnit(): PackageDef = checkNoEscapingPlaceholders {
def topstats(): List[Tree] = {
val ts = new ListBuffer[Tree]
while (in.token == SEMI) in.nextToken()
val start = in.offset
if (in.token == PACKAGE) {
in.nextToken()
if (in.token == OBJECT) {
// TODO - this next line is supposed to be
// ts += packageObjectDef(start)
// but this broke a scaladoc test (run/diagrams-filtering.scala) somehow.
ts ++= joinComment(List(makePackageObject(start, objectDef(in.offset, NoMods))))
if (in.token != EOF) {
acceptStatSep()
ts ++= topStatSeq()
}
} else {
in.flushDoc
val pkg = pkgQualId()
if (in.token == EOF) {
ts += makePackaging(start, pkg, List())
} else if (isStatSep) {
in.nextToken()
ts += makePackaging(start, pkg, topstats())
} else {
ts += inBraces(makePackaging(start, pkg, topStatSeq()))
acceptStatSepOpt()
ts ++= topStatSeq()
}
}
} else {
ts ++= topStatSeq()
}
ts.toList
}
resetPackage()
topstats() match {
case (stat @ PackageDef(_, _)) :: Nil => stat
case stats =>
val start =
if (stats forall (_ == EmptyTree)) 0
else {
val wpos = wrappingPos(stats)
if (wpos.isDefined) wpos.start
else 0
}
makeEmptyPackage(start, stats)
}
}
}
}
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