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Merged
merged 5 commits into from
Jan 16, 2020
Merged

Drop "extended with" syntax #8009

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d76aefe
Drop "extended with" syntax
odersky Jan 15, 2020
815f479
Allow `:` instead of `with` in front of templates
odersky Jan 16, 2020
117b9de
Fix test
odersky Jan 16, 2020
116c1c0
Adapt grammar
odersky Jan 16, 2020
10b7c63
Update check file
odersky Jan 16, 2020
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1 change: 0 additions & 1 deletion compiler/src/dotty/tools/dotc/core/StdNames.scala
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Expand Up @@ -457,7 +457,6 @@ object StdNames {
val eval: N = "eval"
val eqlAny: N = "eqlAny"
val ex: N = "ex"
val extended: N = "extended"
val extension: N = "extension"
val experimental: N = "experimental"
val f: N = "f"
Expand Down
152 changes: 74 additions & 78 deletions compiler/src/dotty/tools/dotc/parsing/Parsers.scala
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Expand Up @@ -913,7 +913,10 @@ object Parsers {
lookahead.nextToken()
if lookahead.token == IDENTIFIER then
lookahead.nextToken()
lookahead.token == COLON
if lookahead.token == COLON then
lookahead.nextToken()
!lookahead.isAfterLineEnd
else false
else false
else false

Expand Down Expand Up @@ -943,7 +946,10 @@ object Parsers {
lookahead.nextToken()
while lookahead.token == LPAREN || lookahead.token == LBRACKET do
lookahead.skipParens()
lookahead.token == COLON || lookahead.token == SUBTYPE
if lookahead.token == COLON then
lookahead.nextToken()
!lookahead.isAfterLineEnd
else lookahead.token == SUBTYPE

def followingIsExtension() =
val lookahead = in.LookaheadScanner()
Expand Down Expand Up @@ -1304,7 +1310,12 @@ object Parsers {
}

def possibleTemplateStart(isNew: Boolean = false): Unit =
if in.token == WITH then
in.observeColonEOL()
if in.token == COLONEOL then
in.nextToken()
if in.token != INDENT then
syntaxError(i"indented definitions expected")
else if in.token == WITH then
in.nextToken()
if in.token != LBRACE && in.token != INDENT then
syntaxError(i"indented definitions or `{` expected")
Expand Down Expand Up @@ -1458,7 +1469,7 @@ object Parsers {
def infixTypeRest(t: Tree): Tree =
infixOps(t, canStartTypeTokens, refinedType, isType = true, isOperator = !isPostfixStar)

/** RefinedType ::= WithType {[nl | `with'] Refinement}
/** RefinedType ::= WithType {[nl] Refinement}
*/
val refinedType: () => Tree = () => refinedTypeRest(withType())

Expand Down Expand Up @@ -2082,7 +2093,8 @@ object Parsers {
}
else simpleExpr()

/** SimpleExpr ::= ‘new’ (ConstrApp [[‘with’] TemplateBody] | TemplateBody)
/** SimpleExpr ::= ‘new’ ConstrApp {`with` ConstrApp} [TemplateBody]
* | ‘new’ TemplateBody
* | BlockExpr
* | ‘$’ ‘{’ Block ‘}’
* | Quoted
Expand Down Expand Up @@ -2177,7 +2189,7 @@ object Parsers {
}
}

/** SimpleExpr ::= ‘new’ ConstrApp {`with` ConstrApp} [[‘with’] TemplateBody]
/** SimpleExpr ::= ‘new’ ConstrApp {`with` ConstrApp} [TemplateBody]
* | ‘new’ TemplateBody
*/
def newExpr(): Tree =
Expand Down Expand Up @@ -3352,7 +3364,7 @@ object Parsers {
syntaxError(s"Only access modifiers are allowed on enum $where")
mods1

/** EnumDef ::= id ClassConstr InheritClauses [‘with’] EnumBody
/** EnumDef ::= id ClassConstr InheritClauses EnumBody
*/
def enumDef(start: Offset, mods: Modifiers): TypeDef = atSpan(start, nameStart) {
val mods1 = checkAccessOnly(mods, "definitions")
Expand Down Expand Up @@ -3415,8 +3427,7 @@ object Parsers {
}

/** GivenDef ::= [GivenSig (‘:’ | <:)] {FunArgTypes ‘=>’} AnnotType ‘=’ Expr
* | [GivenSig ‘:’] {FunArgTypes ‘=>’} ConstrApps [[‘with’] TemplateBody]
* | [id ‘:’] ExtParamClause {GivenParamClause} ‘extended’ ‘with’ ExtMethods
* | [GivenSig ‘:’] {FunArgTypes ‘=>’} ConstrApps [TemplateBody]
* GivenSig ::= [id] [DefTypeParamClause] {GivenParamClause}
* ExtParamClause ::= [DefTypeParamClause] DefParamClause
* ExtMethods ::= [nl] ‘{’ ‘def’ DefDef {semi ‘def’ DefDef} ‘}’
Expand Down Expand Up @@ -3458,83 +3469,68 @@ object Parsers {
if in.token == LPAREN && followingIsParamOrGivenType()
then paramClauses() // todo: ONLY admit a single paramClause
else Nil
val isExtension = isIdent(nme.extended)
def checkAllGivens(vparamss: List[List[ValDef]], what: String) =
vparamss.foreach(_.foreach(vparam =>
if !vparam.mods.is(Given) then syntaxError(em"$what must be `given`", vparam.span)))
if isExtension then
if !name.isEmpty && !hasLabel then
syntaxError(em"name $name of extension clause must be followed by `:`", nameStart)
vparamss match
case (vparam :: Nil) :: vparamss1 if !vparam.mods.is(Given) =>
checkAllGivens(vparamss1, "follow-on parameter in extension clause")
case _ =>
syntaxError("extension clause must start with a single regular parameter", paramsStart)
in.nextToken()
accept(WITH)
val (self, stats) = templateBody()
stats.foreach(checkExtensionMethod(tparams, _))
ModuleDef(name, Template(makeConstructor(tparams, vparamss), Nil, Nil, self, stats))
else
def makeGiven(params: List[ValDef]): List[ValDef] =
params.map(param => param.withMods(param.mods | Given))
def conditionalParents(): List[Tree] =
accept(ARROW)
if in.token == LPAREN && followingIsParam() then
vparamss = vparamss :+ makeGiven(paramClause(vparamss.flatten.length))
conditionalParents()
else
val constrs = constrApps(commaOK = true, templateCanFollow = true)
if in.token == ARROW && constrs.forall(_.isType) then
vparamss = vparamss
:+ typesToGivenParams(constrs, ofClass = false, vparamss.flatten.length)
conditionalParents()
else constrs

val isConditional =
in.token == ARROW
&& vparamss.length == 1
&& (hasLabel || name.isEmpty && tparams.isEmpty)
if !isConditional then checkAllGivens(vparamss, "parameter of given instance")
val parents =
if in.token == SUBTYPE && !hasLabel then
if !mods.is(Inline) then
syntaxError("`<:` is only allowed for given with `inline` modifier")
in.nextToken()
TypeBoundsTree(EmptyTree, annotType()) :: Nil
else if isConditional then
vparamss = vparamss.map(makeGiven)
def makeGiven(params: List[ValDef]): List[ValDef] =
params.map(param => param.withMods(param.mods | Given))
def conditionalParents(): List[Tree] =
accept(ARROW)
if in.token == LPAREN && followingIsParam() then
vparamss = vparamss :+ makeGiven(paramClause(vparamss.flatten.length))
conditionalParents()
else
val constrs = constrApps(commaOK = true, templateCanFollow = true)
if in.token == ARROW && constrs.forall(_.isType) then
vparamss = vparamss
:+ typesToGivenParams(constrs, ofClass = false, vparamss.flatten.length)
conditionalParents()
else
if !hasLabel && !(name.isEmpty && tparams.isEmpty && vparamss.isEmpty) then
accept(COLON)
val constrs = constrApps(commaOK = true, templateCanFollow = true)
if in.token == ARROW && vparamss.isEmpty && constrs.forall(_.isType) then
vparamss = typesToGivenParams(constrs, ofClass = false, 0) :: Nil
conditionalParents()
else
constrs

if in.token == EQUALS && parents.length == 1 && parents.head.isType then
else constrs

val isConditional =
in.token == ARROW
&& vparamss.length == 1
&& (hasLabel || name.isEmpty && tparams.isEmpty)
if !isConditional then checkAllGivens(vparamss, "parameter of given instance")
val parents =
if in.token == SUBTYPE && !hasLabel then
if !mods.is(Inline) then
syntaxError("`<:` is only allowed for given with `inline` modifier")
in.nextToken()
mods1 |= Final
DefDef(name, tparams, vparamss, parents.head, subExpr())
TypeBoundsTree(EmptyTree, annotType()) :: Nil
else if isConditional then
vparamss = vparamss.map(makeGiven)
conditionalParents()
else
parents match
case TypeBoundsTree(_, _) :: _ => syntaxError("`=` expected")
case _ =>
possibleTemplateStart()
val tparams1 = tparams.map(tparam => tparam.withMods(tparam.mods | PrivateLocal))
val vparamss1 = vparamss.map(_.map(vparam =>
vparam.withMods(vparam.mods &~ Param | ParamAccessor | PrivateLocal)))
val templ = templateBodyOpt(makeConstructor(tparams1, vparamss1), parents, Nil)
if tparams.isEmpty && vparamss.isEmpty then ModuleDef(name, templ)
else TypeDef(name.toTypeName, templ)
if !hasLabel && !(name.isEmpty && tparams.isEmpty && vparamss.isEmpty) then
accept(COLON)
val constrs = constrApps(commaOK = true, templateCanFollow = true)
if in.token == ARROW && vparamss.isEmpty && constrs.forall(_.isType) then
vparamss = typesToGivenParams(constrs, ofClass = false, 0) :: Nil
conditionalParents()
else
constrs

if in.token == EQUALS && parents.length == 1 && parents.head.isType then
in.nextToken()
mods1 |= Final
DefDef(name, tparams, vparamss, parents.head, subExpr())
else
parents match
case TypeBoundsTree(_, _) :: _ => syntaxError("`=` expected")
case _ =>
possibleTemplateStart()
val tparams1 = tparams.map(tparam => tparam.withMods(tparam.mods | PrivateLocal))
val vparamss1 = vparamss.map(_.map(vparam =>
vparam.withMods(vparam.mods &~ Param | ParamAccessor | PrivateLocal)))
val templ = templateBodyOpt(makeConstructor(tparams1, vparamss1), parents, Nil)
if tparams.isEmpty && vparamss.isEmpty then ModuleDef(name, templ)
else TypeDef(name.toTypeName, templ)
}
finalizeDef(gdef, mods1, start)
}

/** ExtensionDef ::= [id] ‘of’ ExtParamClause {GivenParamClause} ‘with’ ExtMethods
/** ExtensionDef ::= [id] ‘on’ ExtParamClause {GivenParamClause} ExtMethods
*/
def extensionDef(start: Offset, mods: Modifiers): ModuleDef =
in.nextToken()
Expand Down Expand Up @@ -3580,7 +3576,7 @@ object Parsers {
else Nil
t :: ts

/** Template ::= InheritClauses [[‘with’] TemplateBody]
/** Template ::= InheritClauses [TemplateBody]
* InheritClauses ::= [‘extends’ ConstrApps] [‘derives’ QualId {‘,’ QualId}]
*/
def template(constr: DefDef, isEnum: Boolean = false): Template = {
Expand Down Expand Up @@ -3650,7 +3646,7 @@ object Parsers {
case x: RefTree => atSpan(start, pointOffset(pkg))(PackageDef(x, stats))
}

/** Packaging ::= package QualId [nl | `with'] `{' TopStatSeq `}'
/** Packaging ::= package QualId [nl] `{' TopStatSeq `}'
*/
def packaging(start: Int): Tree = {
val pkg = qualId()
Expand Down
32 changes: 19 additions & 13 deletions compiler/src/dotty/tools/dotc/parsing/Scanners.scala
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Expand Up @@ -550,6 +550,13 @@ object Scanners {
|Previous indent : $lastWidth
|Latest indent : $nextWidth"""

def observeColonEOL(): Unit =
if token == COLON then
lookahead()
val atEOL = isAfterLineEnd
reset()
if atEOL then token = COLONEOL

def observeIndented(): Unit =
if indentSyntax && isNewLine then
val nextWidth = indentWidth(next.offset)
Expand All @@ -575,19 +582,21 @@ object Scanners {
insert(OUTDENT, offset)
case _ =>

def lookahead() = {
prev.copyFrom(this)
lastOffset = lastCharOffset
fetchToken()
}

def reset() = {
next.copyFrom(this)
this.copyFrom(prev)
}

/** - Join CASE + CLASS => CASECLASS, CASE + OBJECT => CASEOBJECT, SEMI + ELSE => ELSE, COLON + <EOL> => COLONEOL
* - Insert missing OUTDENTs at EOF
*/
def postProcessToken(): Unit = {
def lookahead() = {
prev.copyFrom(this)
lastOffset = lastCharOffset
fetchToken()
}
def reset() = {
next.copyFrom(this)
this.copyFrom(prev)
}
def fuse(tok: Int) = {
token = tok
offset = prev.offset
Expand All @@ -611,10 +620,7 @@ object Scanners {
/* skip the trailing comma */
} else reset()
case COLON =>
lookahead()
val atEOL = isAfterLineEnd
reset()
if (colonSyntax && atEOL) token = COLONEOL
if colonSyntax then observeColonEOL()
case EOF | RBRACE =>
currentRegion match {
case r: Indented if !r.isOutermost =>
Expand Down
16 changes: 8 additions & 8 deletions docs/docs/internals/syntax.md
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Expand Up @@ -149,7 +149,7 @@ FunArgTypes ::= InfixType
TypedFunParam ::= id ‘:’ Type
MatchType ::= InfixType `match` ‘{’ TypeCaseClauses ‘}’
InfixType ::= RefinedType {id [nl] RefinedType} InfixOp(t1, op, t2)
RefinedType ::= WithType {[nl | ‘with’] Refinement} RefinedTypeTree(t, ds)
RefinedType ::= WithType {[nl] Refinement} RefinedTypeTree(t, ds)
WithType ::= AnnotType {‘with’ AnnotType} (deprecated)
AnnotType ::= SimpleType {Annotation} Annotated(t, annot)
SimpleType ::= SimpleType TypeArgs AppliedTypeTree(t, args)
Expand Down Expand Up @@ -214,7 +214,7 @@ SimpleExpr ::= Path
| ‘$’ ‘{’ Block ‘}’
| Quoted
| quoteId // only inside splices
| ‘new’ ConstrApp {‘with’ ConstrApp} [[‘with’] TemplateBody] New(constr | templ)
| ‘new’ ConstrApp {‘with’ ConstrApp} [TemplateBody] New(constr | templ)
| ‘new’ TemplateBody
| ‘(’ ExprsInParens ‘)’ Parens(exprs)
| SimpleExpr ‘.’ id Select(expr, id)
Expand Down Expand Up @@ -383,16 +383,16 @@ ClassDef ::= id ClassConstr [Template]
ClassConstr ::= [ClsTypeParamClause] [ConstrMods] ClsParamClauses with DefDef(_, <init>, Nil, vparamss, EmptyTree, EmptyTree) as first stat
ConstrMods ::= {Annotation} [AccessModifier]
ObjectDef ::= id [Template] ModuleDef(mods, name, template) // no constructor
EnumDef ::= id ClassConstr InheritClauses [‘with’] EnumBody EnumDef(mods, name, tparams, template)
EnumDef ::= id ClassConstr InheritClauses EnumBody EnumDef(mods, name, tparams, template)
GivenDef ::= [GivenSig (‘:’ | <:)] {FunArgTypes ‘=>’}
AnnotType ‘=’ Expr
| [GivenSig ‘:’] {FunArgTypes ‘=>’}
ConstrApps [[‘with’] TemplateBody]
ConstrApps [TemplateBody]
GivenSig ::= [id] [DefTypeParamClause] {GivenParamClause}
ExtensionDef ::= [id] ‘of’ ExtParamClause {GivenParamClause} ExtMethods
ExtensionDef ::= [id] ‘on’ ExtParamClause {GivenParamClause} ExtMethods
ExtMethods ::= [nl] ‘{’ ‘def’ DefDef {semi ‘def’ DefDef} ‘}’
ExtParamClause ::= [DefTypeParamClause] ‘(’ DefParam ‘)’
Template ::= InheritClauses [[‘with’] TemplateBody] Template(constr, parents, self, stats)
Template ::= InheritClauses [TemplateBody] Template(constr, parents, self, stats)
InheritClauses ::= [‘extends’ ConstrApps] [‘derives’ QualId {‘,’ QualId}]
ConstrApps ::= ConstrApp {(‘,’ | ‘with’) ConstrApp}
ConstrApp ::= AnnotType {ParArgumentExprs} Apply(tp, args)
Expand All @@ -410,7 +410,7 @@ TemplateStat ::= Import
SelfType ::= id [‘:’ InfixType] ‘=>’ ValDef(_, name, tpt, _)
| ‘this’ ‘:’ InfixType ‘=>’

EnumBody ::= [nl | ‘with’] ‘{’ [SelfType] EnumStat {semi EnumStat} ‘}’
EnumBody ::= [nl] ‘{’ [SelfType] EnumStat {semi EnumStat} ‘}’
EnumStat ::= TemplateStat
| {Annotation [nl]} {Modifier} EnumCase
EnumCase ::= ‘case’ (id ClassConstr [‘extends’ ConstrApps]] | ids)
Expand All @@ -422,7 +422,7 @@ TopStat ::= Import
| Packaging
| PackageObject
|
Packaging ::= ‘package’ QualId [nl | ‘with’] ‘{’ TopStatSeq ‘}’ Package(qid, stats)
Packaging ::= ‘package’ QualId [nl] ‘{’ TopStatSeq ‘}’ Package(qid, stats)
PackageObject ::= ‘package’ ‘object’ ObjectDef object with package in mods.

CompilationUnit ::= {‘package’ QualId semi} TopStatSeq Package(qid, stats)
Expand Down
2 changes: 1 addition & 1 deletion docs/docs/reference/other-new-features/opaques.md
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Expand Up @@ -20,7 +20,7 @@ object Logarithms {
}

// Extension methods define opaque types' public APIs
given logarithmOps: (x: Logarithm) extended with {
extension logarithmOps on (x: Logarithm) {
def toDouble: Double = math.exp(x)
def + (y: Logarithm): Logarithm = Logarithm(math.exp(x) + math.exp(y))
def * (y: Logarithm): Logarithm = x + y
Expand Down
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