package scalaparser
import acyclic.file
import language.implicitConversions
import syntax._
import org.parboiled2._
/**
* Parser for Scala syntax.
*
* The `G` parameter that gets passed in to each rule stands for
* "Greedy", and determines whether or not that rule is to consume
* newlines after the last terminal in that rule. We need to pass it
* everywhere so it can go all the way to the last terminal deep
* inside the parse tree, which can then decide whether or not to
* consume whitespace.
*
* The vast majority of terminals will consume newlines; only rules
* which occur in {} blocks won't have their terminals consume newlines.
* That's why the parser does terminals-consume-newlines-by-default,
* and leaves it up to the dev to thread the `G` variable where-ever
* we want the opposite behavior.
*/
class ScalaSyntax(val input: ParserInput) extends Parser with Basic with Identifiers with Literals {
// Aliases for common things. These things are used in almost every parser
// in the file, so it makes sense to keep them short.
type B = Boolean
val t = true
type R0 = Rule0
/**
* Parses all whitespace, excluding newlines. This is only
* really useful in e.g. {} blocks, where we want to avoid
* capturing newlines so semicolon-inference would work
*/
def WS = rule { zeroOrMore(Basic.WhitespaceChar | Literals.Comment) }
/**
* Parses whitespace, including newlines.
* This is the default for most things
*/
def WL = rule{ zeroOrMore(Basic.WhitespaceChar | Literals.Comment | Basic.Newline) }
/**
* Whitespace which captures or doesn't-capture
* newlines depending on the G that gets passed in
*/
def W(G: B = t) =
if (G) WL
else WS
/**
* By default, all strings and characters greedily
* capture all whitespace immediately after the token.
*/
implicit private[this] def wspStr(s: String): R0 = rule { str(s) ~ WL }
implicit private[this] def wspChar(s: Char): R0 = rule { ch(s) ~ WL }
/**
* Occasionally, you want to decide whether or not to
* capture newlines based on the context, so use this
* and pass in G manually.
*/
def StrW(s: String, G: B): R0 = rule { str(s) ~ W(G) }
def pos = cursor -> cursorChar
/**
* helper printing function
*/
def pr(s: String) = rule { run(println(s"LOGGING $cursor: $s")) }
def Id(G: B = t) = rule { Identifiers.Id ~ W(G) }
def VarId(G: B = t) = rule { Identifiers.VarId ~ W(G) }
def Literal(G: B = t) = rule { Literals.Literal ~ W(G) }
def Semi = rule { Basic.Semi ~ WL }
def Newline = rule { Basic.Newline ~ WL }
def QualId(G: B = t) = rule { oneOrMore(Id(false)) separatedBy '.' ~ W(G) }
def Ids = rule { oneOrMore(Id()) separatedBy ',' }
def Path(G: B = t): R0 = rule {
zeroOrMore(Id(G) ~ '.') ~ "this" ~ zeroOrMore(Id(G)).separatedBy('.') |
StableId(G)
}
def StableId(G: B = t): R0 = rule {
zeroOrMore(Id() ~ '.') ~ ("this" | "super" ~ optional(ClassQualifier)) ~ '.' ~ oneOrMore(Id(G)).separatedBy('.') |
Id(false) ~ zeroOrMore(WL ~ '.' ~ WL ~ Id(false)) ~ W(G)
}
def ClassQualifier = rule { '[' ~ Id() ~ ']' }
def Type: R0 = rule { FunctionArgTypes ~ "=>" ~ Type | InfixType ~ optional(ExistentialClause) }
def FunctionArgTypes = rule { InfixType | '(' ~ optional(oneOrMore(ParamType) separatedBy ',') ~ ')' }
def ExistentialClause = rule { "forSome" ~ '{' ~ oneOrMore(ExistentialDcl).separatedBy(Semi) }
def ExistentialDcl = rule { "type" ~ TypeDcl | "val" ~ ValDcl }
def InfixType = rule { CompoundType ~ zeroOrMore(Id() ~ optional(Newline) ~ CompoundType) }
def CompoundType = rule {
oneOrMore(AnnotType(false)).separatedBy(WL ~ "with") ~ optional(Refinement)
}
def AnnotType(G: B = t) = rule {
SimpleType(false) ~ zeroOrMore(WL ~ Annotation) ~ W(G)
}
def SimpleType(G: B = t): R0 = rule {
BasicType(false) ~
optional(WL ~ '#' ~ Id(false)) ~
optional(WL ~ TypeArgs(false)) ~
W(G)
}
def BasicType(G: B = t): R0 = rule {
'(' ~ Types ~ ')' |
Path() ~ '.' ~ "type" |
StableId(G)
}
def TypeArgs(G: B = t) = rule { '[' ~ Types ~ StrW("]", G) }
def Types = rule { oneOrMore(Type).separatedBy(',') }
def Refinement = rule { optional(Newline) ~ '{' ~ oneOrMore(RefineStat).separatedBy(Semi) ~ '}' }
def RefineStat = rule { "type" ~ TypeDef | Dcl | MATCH }
def TypePat = rule { CompoundType }
def Ascription(G: B = t) = rule { ":" ~ (InfixType | oneOrMore(Annotation) | "_" ~ StrW("*", G)) }
def ParamType = rule { "=>" ~ Type | Type ~ "*" | Type }
def Expr(G: B = t): R0 = rule { (Bindings | optional("implicit") ~ Id() | "_") ~ "=>" ~ Expr(G) | Expr1(G) }
def Expr1(G: B = t): R0 = rule {
IfCFlow(G) |
WhileCFlow(G) |
TryCFlow(G) |
DoWhileCFlow(G) |
ForCFlow(G) |
"throw" ~ Expr(G) |
"return" ~ optional(Expr(G)) |
SimpleExpr() ~ '=' ~ Expr(G) |
PostfixExpr(false) ~ optional("match" ~ '{' ~ CaseClauses ~ StrW("}", false) | Ascription(false)) ~ W(G)
}
def IfCFlow(G: B = t) = rule { "if" ~ '(' ~ Expr() ~ ')' ~ zeroOrMore(Newline) ~ Expr(G) ~ optional(optional(Semi) ~ "else" ~ Expr(G)) }
def WhileCFlow(G: B = t) = rule { "while" ~ '(' ~ Expr() ~ ')' ~ zeroOrMore(Newline) ~ Expr(G) }
def TryCFlow(G: B = t) = rule {
"try" ~ Expr(false) ~
optional(WL ~ "catch" ~ Expr(false)) ~
optional(WL ~ "finally" ~ Expr(false)) ~
W(G)
}
def DoWhileCFlow(G: B = t) = rule { "do" ~ Expr() ~ optional(Semi) ~ "while" ~ '(' ~ Expr() ~ StrW(")", G) }
def ForCFlow(G: B = t) = rule { "for" ~ ('(' ~ Enumerators ~ ')' | '{' ~ Enumerators ~ '}') ~ zeroOrMore(Newline) ~ optional("yield") ~ Expr(G) }
def PostfixExpr(G: B = t): R0 = rule { InfixExpr(G) ~ optional(Id() ~ optional(Newline)) }
def InfixExpr(G: B = t): R0 = rule { PrefixExpr(G) ~ zeroOrMore(Id() ~ optional(Newline) ~ PrefixExpr(G)) }
def PrefixExpr(G: B = t) = rule { optional(anyOf("-+~!")) ~ SimpleExpr(G) }
def SimpleExpr(G: B = t): R0 = rule {
SimpleExpr1(false) ~
zeroOrMore(WL ~ ('.' ~ Id(false) | TypeArgs(false) | ArgumentExprs(false))) ~
optional(WL ~ StrW("_", false)) ~
W(G)
}
def SimpleExpr1(G: B = t) = rule{
"new" ~ (ClassTemplate(G) | TemplateBody(G)) |
BlockExpr(G) |
Literal(G) ~ drop[String] |
Path(G) |
'_' |
'(' ~ optional(Exprs) ~ StrW(")", G)
}
def Exprs: R0 = rule { oneOrMore(Expr()).separatedBy(',') }
def ArgumentExprs(G: B = t): R0 = rule {
'(' ~ optional(Exprs ~ optional(':' ~ '_' ~ '*')) ~ StrW(")", G) |
optional(Newline) ~ BlockExpr(G)
}
def BlockExpr(G: B = t): R0 = rule { '{' ~ (CaseClauses | Block) ~ StrW("}", G) }
def Block: R0 = rule {
zeroOrMore(BlockStat ~ Semi) ~ optional(ResultExpr())
}
def BlockStat: R0 = rule {
Semi |
Import(false) |
zeroOrMore(Annotation) ~ (optional("implicit" | "lazy") ~ Def(false) | zeroOrMore(LocalModifier) ~ TmplDef(false)) |
Expr1(false)
}
def ResultExpr(G: B = t): R0 = rule { (Bindings | optional("implicit") ~ Id() | "_") ~ "=>" ~ Block | Expr1(t) }
def Enumerators: R0 = rule { Generator(false) ~ zeroOrMore(Semi ~ Enumerator(false)) ~ WL }
def Enumerator(G: B = t): R0 = rule { Generator(G) | Guard(G) | Pattern1 ~ '=' ~ Expr(G) }
def Generator(G: B = t): R0 = rule { Pattern1 ~ "<-" ~ Expr(false) ~ optional(WL ~ Guard(false)) ~ W(G) }
def CaseClauses: R0 = rule { oneOrMore(CaseClause) }
def CaseClause: R0 = rule { "case" ~ Pattern ~ optional(Guard(true)) ~ "=>" ~ Block }
def Guard(G: B = t): R0 = rule { "if" ~ PostfixExpr(G) }
def Pattern: R0 = rule {
oneOrMore(Pattern1).separatedBy('|')
}
def Pattern1: R0 = rule { '_' ~ ':' ~ TypePat | VarId() ~ ':' ~ TypePat | Pattern2 }
def Pattern2: R0 = rule { VarId() ~ optional("@" ~ Pattern3) | Pattern3 }
def Pattern3: R0 = rule {
SimplePattern ~ zeroOrMore(Id() ~ SimplePattern)
}
def SimplePattern: R0 = rule {
'_' |
Literal() ~ drop[String] |
'(' ~ optional(Patterns) ~ ')' |
StableId() ~ optional('(' ~ (optional(Patterns ~ ',') ~ optional(VarId() ~ '@') ~ '_' ~ '*' | optional(Patterns)) ~ ')') |
VarId() /*|
XmlPattern*/
}
def Patterns: R0 = rule { '_' ~ '*' | oneOrMore(Pattern).separatedBy(',') }
def TypeParamClause: R0 = rule { '[' ~ oneOrMore(VariantTypeParam).separatedBy(',') ~ ']' }
def FunTypeParamClause: R0 = rule { '[' ~ oneOrMore(TypeParam).separatedBy(',') ~ ']' }
def VariantTypeParam: R0 = rule { zeroOrMore(Annotation) ~ optional(anyOf("+-")) ~ TypeParam }
def TypeParam: R0 = rule { (Id() | '_') ~ optional(TypeParamClause) ~ optional(">:" ~ Type) ~ optional("<:" ~ Type) ~ zeroOrMore("<%" ~ Type) ~ zeroOrMore(':' ~ Type) }
def ParamClauses: R0 = rule { zeroOrMore(ParamClause) ~ optional(optional(Newline) ~ '(' ~ "implicit" ~ Params ~ ')') }
def ParamClause: R0 = rule { optional(Newline) ~ '(' ~ optional(Params) ~ ')' }
def Params: R0 = rule { zeroOrMore(Param).separatedBy(',') }
def Param: R0 = rule { zeroOrMore(Annotation) ~ Id() ~ optional(':' ~ ParamType) ~ optional('=' ~ Expr()) }
def ClassParamClauses(G: B = t): R0 = rule { zeroOrMore(ClassParamClause(G)) ~ optional(optional(Newline) ~ '(' ~ "implicit" ~ ClassParam ~ StrW(")", G)) }
def ClassParamClause(G: B = t): R0 = rule { optional(Newline) ~ '(' ~ optional(ClassParams) ~ StrW(")", G) }
def ClassParams: R0 = rule { oneOrMore(ClassParam).separatedBy(',') }
def ClassParam: R0 = rule { zeroOrMore(Annotation) ~ optional(zeroOrMore(Modifier) ~ ("val" | "var")) ~ Id() ~ ":" ~ ParamType ~ optional("=" ~ Expr()) }
def Bindings: R0 = rule { '(' ~ oneOrMore(Binding).separatedBy(',') ~ ')' }
def Binding: R0 = rule { (Id() | '_') ~ optional(':' ~ Type) }
def Modifier: R0 = rule { LocalModifier | AccessModifier | "override" }
def LocalModifier: R0 = rule { "abstract" | "final" | "sealed" | "implicit" | "lazy" }
def AccessModifier: R0 = rule { ("private" | "protected") ~ optional(AccessQualifier) }
def AccessQualifier: R0 = rule { '[' ~ ("this" | Id()) ~ ']' }
def Annotation: R0 = rule { '@' ~ SimpleType(false) ~ zeroOrMore(WL ~ ArgumentExprs()) }
def ConstrAnnotation: R0 = rule { '@' ~ SimpleType() ~ ArgumentExprs() }
def TemplateBody(G: B = t): R0 = rule {
WL ~
'{' ~
optional(SelfType) ~
TemplateStat ~
zeroOrMore(Semi ~ TemplateStat) ~
WL ~
StrW("}", G)
}
def TemplateStat: R0 = rule {
Import(false) |
zeroOrMore(Annotation ~ optional(Newline)) ~ zeroOrMore(Modifier) ~ (Def(false) | Dcl) |
Expr(false) |
MATCH
}
def SelfType: R0 = rule { "this" ~ ':' ~ Type ~ "=>" | Id() ~ optional(':' ~ Type) ~ "=>" }
def Import(G: B = t): R0 = rule { "import" ~ oneOrMore(ImportExpr(G)).separatedBy(',') }
def ImportExpr(G: B = t): R0 = rule { StableId(G) ~ optional('.' ~ (StrW("_", G) | ImportSelectors(G))) }
def ImportSelectors(G: B = t): R0 = rule { '{' ~ zeroOrMore(ImportSelector ~ ',') ~ (ImportSelector | '_') ~ StrW("}", G) }
def ImportSelector: R0 = rule { Id() ~ optional("=>" ~ (Id() | '_')) }
def Dcl: R0 = rule {
"val" ~ ValDcl |
"var" ~ VarDcl |
"def" ~ FunDcl |
"type" ~ zeroOrMore(Newline) ~ TypeDcl
}
def ValDcl: R0 = rule { Ids ~ ':' ~ Type }
def VarDcl: R0 = rule { Ids ~ ':' ~ Type }
def FunDcl: R0 = rule { FunSig ~ optional(':' ~ Type) }
def FunSig: R0 = rule { Id() ~ optional(FunTypeParamClause) ~ ParamClauses }
def TypeDcl: R0 = rule { Id() ~ optional(TypeParamClause) ~ optional(">:" ~ Type) ~ optional("<:" ~ Type) }
def PatVarDef(G: B = t): R0 = rule { "val" ~ PatDef(G) | "var" ~ VarDef(G) }
def Def(G: B = t): R0 = rule { "def" ~ FunDef(G) | "type" ~ zeroOrMore(Newline) ~ TypeDef | PatVarDef(G) | TmplDef(G) }
def PatDef(G: B = t): R0 = rule { oneOrMore(Pattern2).separatedBy(',') ~ optional(':' ~ Type) ~ '=' ~ Expr(G) }
def VarDef(G: B = t): R0 = rule { Ids ~ ':' ~ Type ~ '=' ~ '_' | PatDef(G) }
def FunDef(G: B = t): R0 = rule {
"this" ~ ParamClause ~ ParamClauses ~ ('=' ~ ConstrExpr | optional(Newline) ~ ConstrBlock) |
FunSig ~ (optional(':' ~ Type) ~ '=' ~ optional("macro") ~ Expr(G) | optional(Newline) ~ '{' ~ Block ~ '}')
}
def TypeDef: R0 = rule { Id() ~ optional(TypeParamClause) ~ '=' ~ Type }
def TmplDef(G: B = t): R0 = rule {
"trait" ~ TraitDef(G) |
optional("case") ~ ("class" ~ ClassDef(G) |
"object" ~ ObjectDef(G))
}
def ClassDef(G: B = t): R0 = rule {
Id() ~
optional(TypeParamClause) ~
zeroOrMore(ConstrAnnotation) ~
optional(AccessModifier) ~
ClassParamClauses(false) ~
ClassTemplateOpt(false) ~
W(G)
}
def TraitDef(G: B = t): R0 = rule { Id() ~ optional(TypeParamClause) ~ TraitTemplateOpt(G) }
def ObjectDef(G: B = t): R0 = rule { Id() ~ ClassTemplateOpt(G) }
def ClassTemplateOpt(G: B = t): R0 = rule {
WL ~ "extends" ~ ClassTemplate(G) |
optional(WL ~ optional("extends") ~ TemplateBody(G))
}
def TraitTemplateOpt(G: B = t): R0 = rule { "extends" ~ TraitTemplate(G) | optional(optional("extends") ~ TemplateBody(G)) }
def ClassTemplate(G: B = t): R0 = rule {
optional(EarlyDefs) ~
ClassParents(false) ~
optional(WL ~ TemplateBody(false)) ~
W(G)
}
def TraitTemplate(G: B = t): R0 = rule {
optional(EarlyDefs) ~ TraitParents(false) ~ optional(TemplateBody(false)) ~ W(G)
}
def ClassParents(G: B = t): R0 = rule {
Constr(false) ~ zeroOrMore(WL ~ "with" ~ AnnotType(G)) ~ W(G)
}
def TraitParents(G: B = t): R0 = rule {
AnnotType(false) ~ zeroOrMore(WL ~ "with" ~ AnnotType(false)) ~ W(G)
}
def Constr(G: B = t): R0 = rule {
AnnotType(false) ~ zeroOrMore(WL ~ ArgumentExprs(false)) ~
W(G)
}
def EarlyDefs: R0 = rule {
'{' ~ optional(oneOrMore(EarlyDef).separatedBy(Semi)) ~ '}' ~ "with"
}
def EarlyDef: R0 = rule {
zeroOrMore(Annotation ~ optional(Newline)) ~ zeroOrMore(Modifier) ~ PatVarDef(false)
}
def ConstrExpr: R0 = rule { ConstrBlock | SelfInvocation }
def ConstrBlock: R0 = rule { '{' ~ SelfInvocation ~ zeroOrMore(Semi ~ BlockStat) ~ '}' }
def SelfInvocation: R0 = rule { "this" ~ oneOrMore(ArgumentExprs()) }
def TopStatSeq: R0 = rule { zeroOrMore(TopStat).separatedBy(Semi) }
def TopStat: R0 = rule { Packaging | PackageObject(false) | Import(false) | zeroOrMore(Annotation ~ optional(Newline)) ~ zeroOrMore(Modifier) ~ TmplDef(false) | MATCH }
def Packaging: R0 = rule { "package" ~ QualId() ~ '{' ~ TopStatSeq ~ '}' }
def PackageObject(G: B = t): R0 = rule { "package" ~ "object" ~ ObjectDef(G) }
def CompilationUnit: Rule1[String] = rule {
capture(
WL ~
zeroOrMore(Semi) ~
zeroOrMore("package" ~ QualId(false)).separatedBy(Semi) ~
TopStatSeq ~
EOI
)
}
}