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/* sbt -- Simple Build Tool
* Copyright 2008, 2010, 2011 Mark Harrah
*/
package sbt.complete
import Parser._
import sbt.Types.{const, left, right, some}
import sbt.Util.{makeList,separate}
sealed trait Parser[+T]
{
def derive(i: Char): Parser[T]
def resultEmpty: Result[T]
def result: Option[T]
def completions(level: Int): Completions
def failure: Option[Failure]
def isTokenStart = false
def ifValid[S](p: => Parser[S]): Parser[S]
def valid: Boolean
}
sealed trait RichParser[A]
{
/** Produces a Parser that applies the original Parser and then applies `next` (in order).*/
def ~[B](next: Parser[B]): Parser[(A,B)]
/** Produces a Parser that applies the original Parser one or more times.*/
def + : Parser[Seq[A]]
/** Produces a Parser that applies the original Parser zero or more times.*/
def * : Parser[Seq[A]]
/** Produces a Parser that applies the original Parser zero or one times.*/
def ? : Parser[Option[A]]
/** Produces a Parser that applies either the original Parser or `b`.*/
def |[B >: A](b: Parser[B]): Parser[B]
/** Produces a Parser that applies either the original Parser or `b`.*/
def ||[B](b: Parser[B]): Parser[Either[A,B]]
/** Produces a Parser that applies the original Parser to the input and then applies `f` to the result.*/
def map[B](f: A => B): Parser[B]
/** Returns the original parser. This is useful for converting literals to Parsers.
* For example, `'c'.id` or `"asdf".id`*/
def id: Parser[A]
def ^^^[B](value: B): Parser[B]
def ??[B >: A](alt: B): Parser[B]
def <~[B](b: Parser[B]): Parser[A]
def ~>[B](b: Parser[B]): Parser[B]
/** Uses the specified message if the original Parser fails.*/
def !!!(msg: String): Parser[A]
/** If an exception is thrown by the original Parser,
* capture it and fail locally instead of allowing the exception to propagate up and terminate parsing.*/
def failOnException: Parser[A]
def unary_- : Parser[Unit]
def & (o: Parser[_]): Parser[A]
def - (o: Parser[_]): Parser[A]
/** Explicitly defines the completions for the original Parser.*/
def examples(s: String*): Parser[A]
/** Explicitly defines the completions for the original Parser.*/
def examples(s: Set[String], check: Boolean = false): Parser[A]
/** Converts a Parser returning a Char sequence to a Parser returning a String.*/
def string(implicit ev: A <:< Seq[Char]): Parser[String]
/** Produces a Parser that filters the original parser.
* If 'f' is not true when applied to the output of the original parser, the Parser returned by this method fails.*/
def filter(f: A => Boolean, msg: String => String): Parser[A]
def flatMap[B](f: A => Parser[B]): Parser[B]
}
object Parser extends ParserMain
{
sealed abstract class Result[+T] {
def isFailure: Boolean
def isValid: Boolean
def errors: Seq[String]
def or[B >: T](b: => Result[B]): Result[B]
def either[B](b: => Result[B]): Result[Either[T,B]]
def map[B](f: T => B): Result[B]
def flatMap[B](f: T => Result[B]): Result[B]
def &&(b: => Result[_]): Result[T]
def filter(f: T => Boolean, msg: => String): Result[T]
def seq[B](b: => Result[B]): Result[(T,B)] = app(b)( (m,n) => (m,n) )
def app[B,C](b: => Result[B])(f: (T, B) => C): Result[C]
def toEither: Either[() => Seq[String], T]
}
final case class Value[+T](value: T) extends Result[T] {
def isFailure = false
def isValid: Boolean = true
def errors = Nil
def app[B,C](b: => Result[B])(f: (T, B) => C): Result[C] = b match {
case fail: Failure => fail
case Value(bv) => Value(f(value, bv))
}
def &&(b: => Result[_]): Result[T] = b match { case f: Failure => f; case _ => this }
def or[B >: T](b: => Result[B]): Result[B] = this
def either[B](b: => Result[B]): Result[Either[T,B]] = Value(Left(value))
def map[B](f: T => B): Result[B] = Value(f(value))
def flatMap[B](f: T => Result[B]): Result[B] = f(value)
def filter(f: T => Boolean, msg: => String): Result[T] = if(f(value)) this else mkFailure(msg)
def toEither = Right(value)
}
final class Failure(mkErrors: => Seq[String]) extends Result[Nothing] {
lazy val errors: Seq[String] = mkErrors
def isFailure = true
def isValid = false
def map[B](f: Nothing => B) = this
def flatMap[B](f: Nothing => Result[B]) = this
def or[B](b: => Result[B]): Result[B] = b match {
case v: Value[B] => v
case f: Failure => concatErrors(f)
}
def either[B](b: => Result[B]): Result[Either[Nothing,B]] = b match {
case Value(v) => Value(Right(v))
case f: Failure => concatErrors(f)
}
def filter(f: Nothing => Boolean, msg: => String) = this
def app[B,C](b: => Result[B])(f: (Nothing, B) => C): Result[C] = this
def &&(b: => Result[_]) = this
def toEither = Left(() => errors)
private[this] def concatErrors(f: Failure) = mkFailures(errors ++ f.errors)
}
def mkFailures(errors: => Seq[String]): Failure = new Failure(errors.distinct)
def mkFailure(error: => String): Failure = new Failure(error :: Nil)
def checkMatches(a: Parser[_], completions: Seq[String])
{
val bad = completions.filter( apply(a)(_).resultEmpty.isFailure)
if(!bad.isEmpty) error("Invalid example completions: " + bad.mkString("'", "', '", "'"))
}
def tuple[A,B](a: Option[A], b: Option[B]): Option[(A,B)] =
(a,b) match { case (Some(av), Some(bv)) => Some(av, bv); case _ => None }
def mapParser[A,B](a: Parser[A], f: A => B): Parser[B] =
a.ifValid {
a.result match
{
case Some(av) => success( f(av) )
case None => new MapParser(a, f)
}
}
def bindParser[A,B](a: Parser[A], f: A => Parser[B]): Parser[B] =
a.ifValid {
a.result match
{
case Some(av) => f(av)
case None => new BindParser(a, f)
}
}
def filterParser[T](a: Parser[T], f: T => Boolean, seen: String, msg: String => String): Parser[T] =
a.ifValid {
a.result match
{
case Some(av) if f(av) => success( av )
case _ => new Filter(a, f, seen, msg)
}
}
def seqParser[A,B](a: Parser[A], b: Parser[B]): Parser[(A,B)] =
a.ifValid { b.ifValid {
(a.result, b.result) match {
case (Some(av), Some(bv)) => success( (av, bv) )
case (Some(av), None) => b map { bv => (av, bv) }
case (None, Some(bv)) => a map { av => (av, bv) }
case (None, None) => new SeqParser(a,b)
}
}}
def choiceParser[A,B](a: Parser[A], b: Parser[B]): Parser[Either[A,B]] =
if(a.valid)
if(b.valid) new HetParser(a,b) else a.map( left.fn )
else
b.map( right.fn )
def opt[T](a: Parser[T]): Parser[Option[T]] =
if(a.valid) new Optional(a) else success(None)
def onFailure[T](delegate: Parser[T], msg: String): Parser[T] =
if(delegate.valid) new OnFailure(delegate, msg) else failure(msg)
def trapAndFail[T](delegate: Parser[T]): Parser[T] =
delegate.ifValid( new TrapAndFail(delegate) )
def zeroOrMore[T](p: Parser[T]): Parser[Seq[T]] = repeat(p, 0, Infinite)
def oneOrMore[T](p: Parser[T]): Parser[Seq[T]] = repeat(p, 1, Infinite)
def repeat[T](p: Parser[T], min: Int = 0, max: UpperBound = Infinite): Parser[Seq[T]] =
repeat(None, p, min, max, Nil)
private[complete] def repeat[T](partial: Option[Parser[T]], repeated: Parser[T], min: Int, max: UpperBound, revAcc: List[T]): Parser[Seq[T]] =
{
assume(min >= 0, "Minimum must be greater than or equal to zero (was " + min + ")")
assume(max >= min, "Minimum must be less than or equal to maximum (min: " + min + ", max: " + max + ")")
def checkRepeated(invalidButOptional: => Parser[Seq[T]]): Parser[Seq[T]] =
repeated match
{
case i: Invalid if min == 0 => invalidButOptional
case i: Invalid => i
case _ =>
repeated.result match
{
case Some(value) => success(revAcc reverse_::: value :: Nil) // revAcc should be Nil here
case None => if(max.isZero) success(revAcc.reverse) else new Repeat(partial, repeated, min, max, revAcc)
}
}
partial match
{
case Some(part) =>
part.ifValid {
part.result match
{
case Some(value) => repeat(None, repeated, min, max, value :: revAcc)
case None => checkRepeated(part.map(lv => (lv :: revAcc).reverse))
}
}
case None => checkRepeated(success(Nil))
}
}
def sub[T](a: Parser[T], b: Parser[_]): Parser[T] = and(a, not(b))
def and[T](a: Parser[T], b: Parser[_]): Parser[T] = a.ifValid( b.ifValid( new And(a, b) ))
}
trait ParserMain
{
implicit def richParser[A](a: Parser[A]): RichParser[A] = new RichParser[A]
{
def ~[B](b: Parser[B]) = seqParser(a, b)
def ||[B](b: Parser[B]) = choiceParser(a,b)
def |[B >: A](b: Parser[B]) = homParser(a,b)
def ? = opt(a)
def * = zeroOrMore(a)
def + = oneOrMore(a)
def map[B](f: A => B) = mapParser(a, f)
def id = a
def ^^^[B](value: B): Parser[B] = a map { _ => value }
def ??[B >: A](alt: B): Parser[B] = a.? map { _ getOrElse alt }
def <~[B](b: Parser[B]): Parser[A] = (a ~ b) map { case av ~ _ => av }
def ~>[B](b: Parser[B]): Parser[B] = (a ~ b) map { case _ ~ bv => bv }
def !!!(msg: String): Parser[A] = onFailure(a, msg)
def failOnException: Parser[A] = trapAndFail(a)
def unary_- = not(a)
def & (o: Parser[_]) = and(a, o)
def - (o: Parser[_]) = sub(a, o)
def examples(s: String*): Parser[A] = examples(s.toSet)
def examples(s: Set[String], check: Boolean = false): Parser[A] = Parser.examples(a, s, check)
def filter(f: A => Boolean, msg: String => String): Parser[A] = filterParser(a, f, "", msg)
def string(implicit ev: A <:< Seq[Char]): Parser[String] = map(_.mkString)
def flatMap[B](f: A => Parser[B]) = bindParser(a, f)
}
implicit def literalRichCharParser(c: Char): RichParser[Char] = richParser(c)
implicit def literalRichStringParser(s: String): RichParser[String] = richParser(s)
def invalid(msgs: => Seq[String]): Parser[Nothing] = Invalid(mkFailures(msgs))
def failure(msg: => String): Parser[Nothing] = invalid(msg :: Nil)
def success[T](value: T): Parser[T] = new ValidParser[T] {
override def result = Some(value)
def resultEmpty = Value(value)
def derive(c: Char) = Parser.failure("Expected end of input.")
def completions(level: Int) = Completions.empty
override def toString = "success(" + value + ")"
}
implicit def range(r: collection.immutable.NumericRange[Char]): Parser[Char] =
charClass(r contains _).examples(r.map(_.toString) : _*)
def chars(legal: String): Parser[Char] =
{
val set = legal.toSet
charClass(set, "character in '" + legal + "'") examples(set.map(_.toString))
}
def charClass(f: Char => Boolean, label: String = "<unspecified>"): Parser[Char] = new CharacterClass(f, label)
implicit def literal(ch: Char): Parser[Char] = new ValidParser[Char] {
def result = None
def resultEmpty = mkFailure( "Expected '" + ch + "'" )
def derive(c: Char) = if(c == ch) success(ch) else new Invalid(resultEmpty)
def completions(level: Int) = Completions.single(Completion.suggestStrict(ch.toString))
override def toString = "'" + ch + "'"
}
implicit def literal(s: String): Parser[String] = stringLiteral(s, 0)
object ~ {
def unapply[A,B](t: (A,B)): Some[(A,B)] = Some(t)
}
def parse[T](str: String, parser: Parser[T]): Either[String, T] =
Parser.result(parser, str).left.map { failures =>
val (msgs,pos) = failures()
ProcessError(str, msgs, pos)
}
def sample(str: String, parser: Parser[_], completions: Boolean = false): Unit =
if(completions) sampleCompletions(str, parser) else sampleParse(str, parser)
def sampleParse(str: String, parser: Parser[_]): Unit =
parse(str, parser) match {
case Left(msg) => println(msg)
case Right(v) => println(v)
}
def sampleCompletions(str: String, parser: Parser[_], level: Int = 1): Unit =
Parser.completions(parser, str, level).get foreach println
// intended to be temporary pending proper error feedback
def result[T](p: Parser[T], s: String): Either[() => (Seq[String],Int), T] =
{
def loop(i: Int, a: Parser[T]): Either[() => (Seq[String],Int), T] =
a match
{
case Invalid(f) => Left( () => (f.errors, i) )
case _ =>
val ci = i+1
if(ci >= s.length)
a.resultEmpty.toEither.left.map { msgs0 => () =>
val msgs = msgs0()
val nonEmpty = if(msgs.isEmpty) "Unexpected end of input" :: Nil else msgs
(nonEmpty, ci)
}
else
loop(ci, a derive s(ci) )
}
loop(-1, p)
}
def apply[T](p: Parser[T])(s: String): Parser[T] =
(p /: s)(derive1)
def derive1[T](p: Parser[T], c: Char): Parser[T] =
if(p.valid) p.derive(c) else p
// The x Completions.empty removes any trailing token completions where append.isEmpty
def completions(p: Parser[_], s: String, level: Int): Completions = apply(p)(s).completions(level) x Completions.empty
def examples[A](a: Parser[A], completions: Set[String], check: Boolean = false): Parser[A] =
if(a.valid) {
a.result match
{
case Some(av) => success( av )
case None =>
if(check) checkMatches(a, completions.toSeq)
new Examples(a, completions)
}
}
else a
def matched(t: Parser[_], seen: Vector[Char] = Vector.empty, partial: Boolean = false): Parser[String] =
t match
{
case i: Invalid => if(partial && !seen.isEmpty) success(seen.mkString) else i
case _ =>
if(t.result.isEmpty)
new MatchedString(t, seen, partial)
else
success(seen.mkString)
}
/** Establishes delegate parser `t` as a single token of tab completion.
* When tab completion of part of this token is requested, the completions provided by the delegate `t` or a later derivative are appended to
* the prefix String already seen by this parser. */
def token[T](t: Parser[T]): Parser[T] = token(t, TokenCompletions.default)
/** Establishes delegate parser `t` as a single token of tab completion.
* When tab completion of part of this token is requested, no completions are returned if `hide` returns true for the current tab completion level.
* Otherwise, the completions provided by the delegate `t` or a later derivative are appended to the prefix String already seen by this parser.*/
def token[T](t: Parser[T], hide: Int => Boolean): Parser[T] = token(t, TokenCompletions.default.hideWhen(hide))
/** Establishes delegate parser `t` as a single token of tab completion.
* When tab completion of part of this token is requested, `description` is displayed for suggestions and no completions are ever performed. */
def token[T](t: Parser[T], description: String): Parser[T] = token(t, TokenCompletions.displayOnly(description))
/** Establishes delegate parser `t` as a single token of tab completion.
* When tab completion of part of this token is requested, `display` is used as the printed suggestion, but the completions from the delegate
* parser `t` are used to complete if unambiguous. */
def tokenDisplay[T](t: Parser[T], display: String): Parser[T] =
token(t, TokenCompletions.overrideDisplay(display))
def token[T](t: Parser[T], complete: TokenCompletions): Parser[T] =
mkToken(t, "", complete)
@deprecated("Use a different `token` overload.", "0.12.1")
def token[T](t: Parser[T], seen: String, track: Boolean, hide: Int => Boolean): Parser[T] =
{
val base = if(track) TokenCompletions.default else TokenCompletions.displayOnly(seen)
token(t, base.hideWhen(hide))
}
private[sbt] def mkToken[T](t: Parser[T], seen: String, complete: TokenCompletions): Parser[T] =
if(t.valid && !t.isTokenStart)
if(t.result.isEmpty) new TokenStart(t, seen, complete) else t
else
t
def homParser[A](a: Parser[A], b: Parser[A]): Parser[A] =
if(a.valid)
if(b.valid) new HomParser(a, b) else a
else
b
def not(p: Parser[_]): Parser[Unit] = p.result match {
case None => new Not(p)
case Some(_) => failure("Excluded.")
}
def oneOf[T](p: Seq[Parser[T]]): Parser[T] = p.reduceLeft(_ | _)
def seq[T](p: Seq[Parser[T]]): Parser[Seq[T]] = seq0(p, Nil)
def seq0[T](p: Seq[Parser[T]], errors: => Seq[String]): Parser[Seq[T]] =
{
val (newErrors, valid) = separate(p) { case Invalid(f) => Left(f.errors); case ok => Right(ok) }
def combinedErrors = errors ++ newErrors.flatten
if(valid.isEmpty) invalid(combinedErrors) else new ParserSeq(valid, combinedErrors)
}
def stringLiteral(s: String, start: Int): Parser[String] =
{
val len = s.length
if(len == 0) error("String literal cannot be empty") else if(start >= len) success(s) else new StringLiteral(s, start)
}
}
sealed trait ValidParser[T] extends Parser[T]
{
final def valid = true
final def failure = None
final def ifValid[S](p: => Parser[S]): Parser[S] = p
}
private final case class Invalid(fail: Failure) extends Parser[Nothing]
{
def failure = Some(fail)
def result = None
def resultEmpty = fail
def derive(c: Char) = error("Invalid.")
def completions(level: Int) = Completions.nil
override def toString = fail.errors.mkString("; ")
def valid = false
def ifValid[S](p: => Parser[S]): Parser[S] = this
}
private final class TrapAndFail[A](a: Parser[A]) extends ValidParser[A]
{
def result = try { a.result } catch { case e: Exception => None }
def resultEmpty = try { a.resultEmpty } catch { case e: Exception => fail(e) }
def derive(c: Char) = try { trapAndFail(a derive c) } catch { case e: Exception => Invalid(fail(e)) }
def completions(level: Int) = try { a.completions(level) } catch { case e: Exception => Completions.nil }
override def toString = "trap(" + a + ")"
override def isTokenStart = a.isTokenStart
private[this] def fail(e: Exception): Failure = mkFailure(e.toString)
}
private final class OnFailure[A](a: Parser[A], message: String) extends ValidParser[A]
{
def result = a.result
def resultEmpty = a.resultEmpty match { case f: Failure => mkFailure(message); case v: Value[A] => v }
def derive(c: Char) = onFailure(a derive c, message)
def completions(level: Int) = a.completions(level)
override def toString = "(" + a + " !!! \"" + message + "\" )"
override def isTokenStart = a.isTokenStart
}
private final class SeqParser[A,B](a: Parser[A], b: Parser[B]) extends ValidParser[(A,B)]
{
lazy val result = tuple(a.result,b.result)
lazy val resultEmpty = a.resultEmpty seq b.resultEmpty
def derive(c: Char) =
{
val common = a.derive(c) ~ b
a.resultEmpty match
{
case Value(av) => common | b.derive(c).map(br => (av,br))
case _: Failure => common
}
}
def completions(level: Int) = a.completions(level) x b.completions(level)
override def toString = "(" + a + " ~ " + b + ")"
}
private final class HomParser[A](a: Parser[A], b: Parser[A]) extends ValidParser[A]
{
lazy val result = tuple(a.result, b.result) map (_._1)
def derive(c: Char) = (a derive c) | (b derive c)
lazy val resultEmpty = a.resultEmpty or b.resultEmpty
def completions(level: Int) = a.completions(level) ++ b.completions(level)
override def toString = "(" + a + " | " + b + ")"
}
private final class HetParser[A,B](a: Parser[A], b: Parser[B]) extends ValidParser[Either[A,B]]
{
lazy val result = tuple(a.result, b.result) map { case (a,b) => Left(a) }
def derive(c: Char) = (a derive c) || (b derive c)
lazy val resultEmpty = a.resultEmpty either b.resultEmpty
def completions(level: Int) = a.completions(level) ++ b.completions(level)
override def toString = "(" + a + " || " + b + ")"
}
private final class ParserSeq[T](a: Seq[Parser[T]], errors: => Seq[String]) extends ValidParser[Seq[T]]
{
assert(!a.isEmpty)
lazy val resultEmpty: Result[Seq[T]] =
{
val res = a.map(_.resultEmpty)
val (failures, values) = separate(res)(_.toEither)
// if(failures.isEmpty) Value(values) else mkFailures(failures.flatMap(_()) ++ errors)
if(values.nonEmpty) Value(values) else mkFailures(failures.flatMap(_()) ++ errors)
}
def result = {
val success = a.flatMap(_.result)
if(success.length == a.length) Some(success) else None
}
def completions(level: Int) = a.map(_.completions(level)).reduceLeft(_ ++ _)
def derive(c: Char) = seq0(a.map(_ derive c), errors)
override def toString = "seq(" + a + ")"
}
private final class BindParser[A,B](a: Parser[A], f: A => Parser[B]) extends ValidParser[B]
{
lazy val result = a.result flatMap { av => f(av).result }
lazy val resultEmpty = a.resultEmpty flatMap { av => f(av).resultEmpty }
def completions(level: Int) =
a.completions(level) flatMap { c =>
apply(a)(c.append).resultEmpty match {
case _: Failure => Completions.strict(Set.empty + c)
case Value(av) => c x f(av).completions(level)
}
}
def derive(c: Char) =
{
val common = a derive c flatMap f
a.resultEmpty match
{
case Value(av) => common | derive1(f(av), c)
case _: Failure => common
}
}
override def isTokenStart = a.isTokenStart
override def toString = "bind(" + a + ")"
}
private final class MapParser[A,B](a: Parser[A], f: A => B) extends ValidParser[B]
{
lazy val result = a.result map f
lazy val resultEmpty = a.resultEmpty map f
def derive(c: Char) = (a derive c) map f
def completions(level: Int) = a.completions(level)
override def isTokenStart = a.isTokenStart
override def toString = "map(" + a + ")"
}
private final class Filter[T](p: Parser[T], f: T => Boolean, seen: String, msg: String => String) extends ValidParser[T]
{
def filterResult(r: Result[T]) = r.filter(f, msg(seen))
lazy val result = p.result filter f
lazy val resultEmpty = filterResult(p.resultEmpty)
def derive(c: Char) = filterParser(p derive c, f, seen + c, msg)
def completions(level: Int) = p.completions(level) filterS { s => filterResult(apply(p)(s).resultEmpty).isValid }
override def toString = "filter(" + p + ")"
override def isTokenStart = p.isTokenStart
}
private final class MatchedString(delegate: Parser[_], seenV: Vector[Char], partial: Boolean) extends ValidParser[String]
{
lazy val seen = seenV.mkString
def derive(c: Char) = matched(delegate derive c, seenV :+ c, partial)
def completions(level: Int) = delegate.completions(level)
def result = if(delegate.result.isDefined) Some(seen) else None
def resultEmpty = delegate.resultEmpty match { case f: Failure if !partial => f; case _ => Value(seen) }
override def isTokenStart = delegate.isTokenStart
override def toString = "matched(" + partial + ", " + seen + ", " + delegate + ")"
}
private final class TokenStart[T](delegate: Parser[T], seen: String, complete: TokenCompletions) extends ValidParser[T]
{
def derive(c: Char) = mkToken( delegate derive c, seen + c, complete)
def completions(level: Int) = complete match {
case dc: TokenCompletions.Delegating => dc.completions(seen, level, delegate.completions(level))
case fc: TokenCompletions.Fixed => fc.completions(seen, level)
}
def result = delegate.result
def resultEmpty = delegate.resultEmpty
override def isTokenStart = true
override def toString = "token('" + complete + ", " + delegate + ")"
}
private final class And[T](a: Parser[T], b: Parser[_]) extends ValidParser[T]
{
lazy val result = tuple(a.result,b.result) map { _._1 }
def derive(c: Char) = (a derive c) & (b derive c)
def completions(level: Int) = a.completions(level).filterS(s => apply(b)(s).resultEmpty.isValid )
lazy val resultEmpty = a.resultEmpty && b.resultEmpty
}
private final class Not(delegate: Parser[_]) extends ValidParser[Unit]
{
def derive(c: Char) = if(delegate.valid) not(delegate derive c) else this
def completions(level: Int) = Completions.empty
def result = None
lazy val resultEmpty = delegate.resultEmpty match {
case f: Failure => Value(())
case v: Value[_] => mkFailure("Excluded.")
}
}
private final class Examples[T](delegate: Parser[T], fixed: Set[String]) extends ValidParser[T]
{
def derive(c: Char) = examples(delegate derive c, fixed.collect { case x if x.length > 0 && x(0) == c => x substring 1 })
def result = delegate.result
lazy val resultEmpty = delegate.resultEmpty
def completions(level: Int) =
if(fixed.isEmpty)
if(resultEmpty.isValid) Completions.nil else Completions.empty
else
Completions(fixed map(f => Completion.suggestion(f)) )
override def toString = "examples(" + delegate + ", " + fixed.take(2) + ")"
}
private final class StringLiteral(str: String, start: Int) extends ValidParser[String]
{
assert(0 <= start && start < str.length)
def failMsg = "Expected '" + str + "'"
def resultEmpty = mkFailure(failMsg)
def result = None
def derive(c: Char) = if(str.charAt(start) == c) stringLiteral(str, start+1) else new Invalid(resultEmpty)
def completions(level: Int) = Completions.single(Completion.suggestion(str.substring(start)))
override def toString = '"' + str + '"'
}
private final class CharacterClass(f: Char => Boolean, label: String) extends ValidParser[Char]
{
def result = None
def resultEmpty = mkFailure("Expected " + label)
def derive(c: Char) = if( f(c) ) success(c) else Invalid(resultEmpty)
def completions(level: Int) = Completions.empty
override def toString = "class(" + label + ")"
}
private final class Optional[T](delegate: Parser[T]) extends ValidParser[Option[T]]
{
def result = delegate.result map some.fn
def resultEmpty = Value(None)
def derive(c: Char) = (delegate derive c).map(some.fn)
def completions(level: Int) = Completion.empty +: delegate.completions(level)
override def toString = delegate.toString + "?"
}
private final class Repeat[T](partial: Option[Parser[T]], repeated: Parser[T], min: Int, max: UpperBound, accumulatedReverse: List[T]) extends ValidParser[Seq[T]]
{
assume(0 <= min, "Minimum occurences must be non-negative")
assume(max >= min, "Minimum occurences must be less than the maximum occurences")
def derive(c: Char) =
partial match
{
case Some(part) =>
val partD = repeat(Some(part derive c), repeated, min, max, accumulatedReverse)
part.resultEmpty match
{
case Value(pv) => partD | repeatDerive(c, pv :: accumulatedReverse)
case _: Failure => partD
}
case None => repeatDerive(c, accumulatedReverse)
}
def repeatDerive(c: Char, accRev: List[T]): Parser[Seq[T]] = repeat(Some(repeated derive c), repeated, (min - 1) max 0, max.decrement, accRev)
def completions(level: Int) =
{
def pow(comp: Completions, exp: Completions, n: Int): Completions =
if(n == 1) comp else pow(comp x exp, exp, n - 1)
val repC = repeated.completions(level)
val fin = if(min == 0) Completion.empty +: repC else pow(repC, repC, min)
partial match
{
case Some(p) => p.completions(level) x fin
case None => fin
}
}
def result = None
lazy val resultEmpty: Result[Seq[T]] =
{
val partialAccumulatedOption =
partial match
{
case None => Value(accumulatedReverse)
case Some(partialPattern) => partialPattern.resultEmpty.map(_ :: accumulatedReverse)
}
(partialAccumulatedOption app repeatedParseEmpty)(_ reverse_::: _)
}
private def repeatedParseEmpty: Result[List[T]] =
{
if(min == 0)
Value(Nil)
else
// forced determinism
for(value <- repeated.resultEmpty) yield
makeList(min, value)
}
override def toString = "repeat(" + min + "," + max +"," + partial + "," + repeated + ")"
}
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