scala.util.parsing.combinator.lexical

Lexical

class Lexical extends Scanners with Tokens

This component complements the Scanners component with common operations for lexical parsers.

{@see StdLexical} for a concrete implementation for a simple, Scala-like language.

Attributes
abstract
Source
Lexical.scala
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  1. Lexical
  2. Tokens
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Visibility
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Instance Constructors

  1. new Lexical ()

Type Members

  1. type Elem = Char

    the type of input elements the provided parsers consume (When consuming invidual characters, a parser is typically called a scanner, which produces tokens that are consumed by what is normally called a parser. Nonetheless, the same principles apply, regardless of the input type.)

    the type of input elements the provided parsers consume (When consuming invidual characters, a parser is typically called a scanner, which produces tokens that are consumed by what is normally called a parser. Nonetheless, the same principles apply, regardless of the input type.)

    Definition Classes
    ScannersParsers
  2. case class Error (msg: String, next: Input) extends NoSuccess with Product with Serializable

    The fatal failure case of ParseResult: contains an error-message and the remaining input.

  3. case class ErrorToken (msg: String) extends Token with Product with Serializable

    A class of error tokens.

  4. case class Failure (msg: String, next: Input) extends NoSuccess with Product with Serializable

    The failure case of ParseResult: contains an error-message and the remaining input.

  5. type Input = Reader[Elem]

    The parser input is an abstract reader of input elements, i.

    The parser input is an abstract reader of input elements, i.e. the type of input the parsers in this component expect.

    Definition Classes
    Parsers
  6. class NoSuccess extends ParseResult[Nothing]

    A common super-class for unsuccessful parse results

  7. trait OnceParser [+T] extends Parser[T]

    A parser whose ~ combinator disallows back-tracking.

  8. class ParseResult [+T] extends AnyRef

    A base class for parser results.

  9. class Parser [+T] extends (Input) ⇒ ParseResult[T]

    The root class of parsers.

  10. class Scanner extends Reader[Token]

    Scanner is essentially(*) a parser that produces Token's from a stream of characters. The tokens it produces are typically passed to parsers in <code>TokenParsers</code>. Note: (*) <code>Scanner</code> is really a Reader' of Token's

  11. case class Success [+T] (result: T, next: Input) extends ParseResult[T] with Product with Serializable

    The success case of ParseResult: contains the result and the remaining input.

  12. class Token extends AnyRef

    Objects of this type are produced by a lexical parser or scanner, and consumed by a parser {@see scala.util.parsing.combinator.syntactical.TokenParsers}.

  13. case class ~ [+a, +b] (_1: a, _2: b) extends Product with Serializable

Abstract Value Members

  1. def token : Parser[Token]

    a parser that produces a token (from a stream of characters)

    a parser that produces a token (from a stream of characters)

    Attributes
    abstract
    Definition Classes
    Scanners
  2. def whitespace : Parser[Any]

    a parser for white-space -- its result will be discarded

    a parser for white-space -- its result will be discarded

    Attributes
    abstract
    Definition Classes
    Scanners

Concrete Value Members

  1. def != (arg0: AnyRef): Boolean

    Attributes
    final
    Definition Classes
    AnyRef
  2. def != (arg0: Any): Boolean

    Test two objects for inequality.

    Test two objects for inequality.

    returns

    true if !(this == that), false otherwise.

    Attributes
    final
    Definition Classes
    Any
  3. def ## (): Int

    Equivalent to x.hashCode except for boxed numeric types.

    Equivalent to x.hashCode except for boxed numeric types. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them.

    returns

    a hash value consistent with ==

    Attributes
    final
    Definition Classes
    AnyRef → Any
  4. def == (arg0: AnyRef): Boolean

    Attributes
    final
    Definition Classes
    AnyRef
  5. def == (arg0: Any): Boolean

    Test two objects for equality.

    Test two objects for equality.

    returns

    true if the receiver object is equivalent to the argument; false otherwise.

    Attributes
    final
    Definition Classes
    Any
  6. object EOF extends Token with Product with Serializable

    A class for end-of-file tokens

  7. object NoSuccess extends AnyRef

    An extractor so NoSuccess(msg, next) can be used in matches.

  8. def OnceParser [T] (f: (Input) ⇒ ParseResult[T]): Parser[T] with OnceParser[T]

    Definition Classes
    Parsers
  9. def Parser [T] (f: (Input) ⇒ ParseResult[T]): Parser[T]

    Definition Classes
    Parsers
  10. def accept [U] (expected: String, f: PartialFunction[Elem, U]): Parser[U]

    The parser that matches an element in the domain of the partial function f' If f' is defined on the first element in the input, f' is applied to it to produce this parser's result. Example: The parser <code>accept("name", {case Identifier(n) => Name(n)})</code> accepts an <code>Identifier(n)</code> and returns a <code>Name(n)</code>.

    The parser that matches an element in the domain of the partial function f' If f' is defined on the first element in the input, f' is applied to it to produce this parser's result. Example: The parser <code>accept("name", {case Identifier(n) => Name(n)})</code> accepts an <code>Identifier(n)</code> and returns a <code>Name(n)</code>.

    expected

    a description of the kind of element this parser expects (for error messages)

    f

    a partial function that determines when this parser is successful and what its output is

    returns

    A parser that succeeds if f' is applicable to the first element of the input, applying f' to it to produce the result.

    Definition Classes
    Parsers
  11. def accept [ES] (es: ES)(implicit arg0: (ES) ⇒ List[Elem]): Parser[List[Elem]]

    A parser that matches only the given list of element es' accept(es) succeeds if the input subsequently provides the elements in the list es'.

    A parser that matches only the given list of element es' accept(es) succeeds if the input subsequently provides the elements in the list es'.

    es

    the list of expected elements

    returns

    a Parser that recognizes a specified list of elements

    Definition Classes
    Parsers
  12. implicit def accept (e: Elem): Parser[Elem]

    A parser that matches only the given element e' The method is implicit so that elements can automatically be lifted to their parsers. For example, when parsing Token's, Identifier("new") (which is a Token') can be used directly, instead of first creating a Parser' using accept(Identifier("new")).

    A parser that matches only the given element e' The method is implicit so that elements can automatically be lifted to their parsers. For example, when parsing Token's, Identifier("new") (which is a Token') can be used directly, instead of first creating a Parser' using accept(Identifier("new")).

    e

    the Elem' that must be the next piece of input for the returned parser to succeed

    returns

    a tParser' that succeeds if e' is the next available input.

    Attributes
    implicit
    Definition Classes
    Parsers
  13. def acceptIf (p: (Elem) ⇒ Boolean)(err: (Elem) ⇒ String): Parser[Elem]

    Definition Classes
    Parsers
  14. def acceptMatch [U] (expected: String, f: PartialFunction[Elem, U]): Parser[U]

    Definition Classes
    Parsers
  15. def acceptSeq [ES] (es: ES)(implicit arg0: (ES) ⇒ Iterable[Elem]): Parser[List[Elem]]

    Definition Classes
    Parsers
  16. def asInstanceOf [T0] : T0

    Cast the receiver object to be of type T0.

    Cast the receiver object to be of type T0.

    Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression 1.asInstanceOf[String] will throw a ClassCastException at runtime, while the expression List(1).asInstanceOf[List[String]] will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested type.

    returns

    the receiver object.

    Attributes
    final
    Definition Classes
    Any
  17. def chainl1 [T, U] (first: ⇒ Parser[T], p: ⇒ Parser[U], q: ⇒ Parser[(T, U) ⇒ T]): Parser[T]

    A parser generator that, roughly, generalises the rep1sep generator so that q', which parses the separator, produces a left-associative function that combines the elements it separates.

    A parser generator that, roughly, generalises the rep1sep generator so that q', which parses the separator, produces a left-associative function that combines the elements it separates.

    first

    a parser that parses the first element

    p

    a parser that parses the subsequent elements

    q

    a parser that parses the token(s) separating the elements, yielding a left-associative function that combines two elements into one

    Definition Classes
    Parsers
  18. def chainl1 [T] (p: ⇒ Parser[T], q: ⇒ Parser[(T, T) ⇒ T]): Parser[T]

    A parser generator that, roughly, generalises the rep1sep generator so that q', which parses the separator, produces a left-associative function that combines the elements it separates. From: J. Fokker. Functional parsers. In J. Jeuring and E. Meijer, editors, Advanced Functional Programming, volume 925 of Lecture Notes in Computer Science, pages 1--23. Springer, 1995.

    A parser generator that, roughly, generalises the rep1sep generator so that q', which parses the separator, produces a left-associative function that combines the elements it separates. From: J. Fokker. Functional parsers. In J. Jeuring and E. Meijer, editors, Advanced Functional Programming, volume 925 of Lecture Notes in Computer Science, pages 1--23. Springer, 1995.

    p

    a parser that parses the elements

    q

    a parser that parses the token(s) separating the elements, yielding a left-associative function that combines two elements into one

    Definition Classes
    Parsers
  19. def chainr1 [T, U] (p: ⇒ Parser[T], q: ⇒ Parser[(T, U) ⇒ U], combine: (T, U) ⇒ U, first: U): Parser[U]

    A parser generator that generalises the rep1sep generator so that q', which parses the separator, produces a right-associative function that combines the elements it separates. Additionally, The right-most (last) element and the left-most combining function have to be supplied. rep1sep(p: Parser[T], q) corresponds to chainr1(p, q ^^ cons, cons, Nil) (where val cons = (x: T, y: List[T]) => x :: y)

    A parser generator that generalises the rep1sep generator so that q', which parses the separator, produces a right-associative function that combines the elements it separates. Additionally, The right-most (last) element and the left-most combining function have to be supplied. rep1sep(p: Parser[T], q) corresponds to chainr1(p, q ^^ cons, cons, Nil) (where val cons = (x: T, y: List[T]) => x :: y)

    p

    a parser that parses the elements

    q

    a parser that parses the token(s) separating the elements, yielding a right-associative function that combines two elements into one

    combine

    the "last" (left-most) combination function to be applied

    first

    the "first" (right-most) element to be combined

    Definition Classes
    Parsers
  20. def chrExcept (cs: Char*): Parser[Elem]

    A character-parser that matches any character except the ones given in cs' (and returns it)

  21. def clone (): AnyRef

    Create a copy of the receiver object.

    Create a copy of the receiver object.

    The default implementation of the clone method is platform dependent.

    returns

    a copy of the receiver object.

    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws()
  22. def commit [T] (p: ⇒ Parser[T]): Parser[T]

    Wrap a parser so that its failures become errors (the | combinator will give up as soon as it encounters an error, on failure it simply tries the next alternative)

    Wrap a parser so that its failures become errors (the | combinator will give up as soon as it encounters an error, on failure it simply tries the next alternative)

    Definition Classes
    Parsers
  23. def digit : Parser[Elem]

    A character-parser that matches a digit (and returns it)

  24. def elem (e: Elem): Parser[Elem]

    A parser that matches only the given element e' elem(e) succeeds if the input starts with an element e'

    A parser that matches only the given element e' elem(e) succeeds if the input starts with an element e'

    e

    the Elem' that must be the next piece of input for the returned parser to succeed

    returns

    a Parser' that succeeds if e' is the next available input (and returns it).

    Definition Classes
    Parsers
  25. def elem (kind: String, p: (Elem) ⇒ Boolean): Parser[Elem]

    A parser matching input elements that satisfy a given predicate

    A parser matching input elements that satisfy a given predicate

    elem(kind, p) succeeds if the input starts with an element e' for which p(e) is true.

    kind

    The element kind, used for error messages

    p

    A predicate that determines which elements match. @return

    Definition Classes
    Parsers
  26. def eq (arg0: AnyRef): Boolean

    Tests whether the argument (arg0) is a reference to the receiver object (this).

    Tests whether the argument (arg0) is a reference to the receiver object (this).

    The eq method implements an equivalence relation on non-null instances of AnyRef, and has three additional properties:

    • It is consistent: for any non-null instances x and y of type AnyRef, multiple invocations of x.eq(y) consistently returns true or consistently returns false.
    • For any non-null instance x of type AnyRef, x.eq(null) and null.eq(x) returns false.
    • null.eq(null) returns true.

    When overriding the equals or hashCode methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).

    returns

    true if the argument is a reference to the receiver object; false otherwise.

    Attributes
    final
    Definition Classes
    AnyRef
  27. def equals (arg0: Any): Boolean

    The equality method for reference types.

    The equality method for reference types. See equals in Any.

    returns

    true if the receiver object is equivalent to the argument; false otherwise.

    Definition Classes
    AnyRef → Any
  28. def err (msg: String): Parser[Nothing]

    A parser that results in an error

    A parser that results in an error

    msg

    The error message describing the failure.

    returns

    A parser that always fails with the specified error message.

    Definition Classes
    Parsers
  29. def errorToken (msg: String): Token

    This token is produced by a scanner {@see Scanner} when scanning failed.

    This token is produced by a scanner {@see Scanner} when scanning failed.

    Definition Classes
    Tokens
  30. def failure (msg: String): Parser[Nothing]

    A parser that always fails

    A parser that always fails

    msg

    The error message describing the failure.

    returns

    A parser that always fails with the specified error message.

    Definition Classes
    Parsers
  31. def finalize (): Unit

    Called by the garbage collector on the receiver object when there are no more references to the object.

    Called by the garbage collector on the receiver object when there are no more references to the object.

    The details of when and if the finalize method is invoked, as well as the interaction between finalize and non-local returns and exceptions, are all platform dependent.

    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws()
  32. def getClass (): java.lang.Class[_ <: java.lang.Object]

    A representation that corresponds to the dynamic class of the receiver object.

    A representation that corresponds to the dynamic class of the receiver object.

    The nature of the representation is platform dependent.

    returns

    a representation that corresponds to the dynamic class of the receiver object.

    Attributes
    final
    Definition Classes
    AnyRef
  33. def guard [T] (p: ⇒ Parser[T]): Parser[T]

    A parser generator for guard expressions.

    A parser generator for guard expressions. The resulting parser will fail or succeed just like the one given as parameter but it will not consume any input.

    p

    a Parser' that is to be applied to the input

    returns

    A parser that returns success if and only if 'p' succeeds but never consumes any input

    Definition Classes
    Parsers
  34. def hashCode (): Int

    The hashCode method for reference types.

    The hashCode method for reference types. See hashCode in Any.

    returns

    the hash code value for this object.

    Definition Classes
    AnyRef → Any
  35. def isInstanceOf [T0] : Boolean

    Test whether the dynamic type of the receiver object is T0.

    Test whether the dynamic type of the receiver object is T0.

    Note that the result of the test is modulo Scala's erasure semantics. Therefore the expression 1.isInstanceOf[String] will return false, while the expression List(1).isInstanceOf[List[String]] will return true. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the specified type.

    returns

    true if the receiver object is an instance of erasure of type T0; false otherwise.

    Attributes
    final
    Definition Classes
    Any
  36. var lastNoSuccess : NoSuccess

    Definition Classes
    Parsers
  37. def letter : Parser[Elem]

    A character-parser that matches a letter (and returns it)

  38. def log [T] (p: ⇒ Parser[T])(name: String): Parser[T]

    Definition Classes
    Parsers
  39. def mkList [T] : (~[T, List[T]]) ⇒ List[T]

    Definition Classes
    Parsers
  40. def ne (arg0: AnyRef): Boolean

    Equivalent to !(this eq that).

    Equivalent to !(this eq that).

    returns

    true if the argument is not a reference to the receiver object; false otherwise.

    Attributes
    final
    Definition Classes
    AnyRef
  41. def not [T] (p: ⇒ Parser[T]): Parser[Unit]

    Wrap a parser so that its failures&errors become success and vice versa -- it never consumes any input

    Wrap a parser so that its failures&errors become success and vice versa -- it never consumes any input

    Definition Classes
    Parsers
  42. def notify (): Unit

    Wakes up a single thread that is waiting on the receiver object's monitor.

    Wakes up a single thread that is waiting on the receiver object's monitor.

    Attributes
    final
    Definition Classes
    AnyRef
  43. def notifyAll (): Unit

    Wakes up all threads that are waiting on the receiver object's monitor.

    Wakes up all threads that are waiting on the receiver object's monitor.

    Attributes
    final
    Definition Classes
    AnyRef
  44. def opt [T] (p: ⇒ Parser[T]): Parser[Option[T]]

    A parser generator for optional sub-phrases.

    A parser generator for optional sub-phrases.

    opt(p) is a parser that returns Some(x)' if p' returns x' and None' if p' fails

    p

    A Parser' that is tried on the input

    returns

    a Parser' that always succeeds: either with the result provided by p' or with the empty result

    Definition Classes
    Parsers
  45. def phrase [T] (p: Parser[T]): Parser[T]

    A parser generator delimiting whole phrases (i.

    A parser generator delimiting whole phrases (i.e. programs).

    phrase(p) succeeds if p succeeds and no input is left over after p.

    p

    the parser that must consume all input for the resulting parser to succeed.

    returns

    a parser that has the same result as p', but that only succeeds if <code>p</code> consumed all the input.

    Definition Classes
    Parsers
  46. def positioned [T <: Positional] (p: ⇒ Parser[T]): Parser[T]

    positioned' decorates a parser's result with the start position of the input it consumed.

    positioned' decorates a parser's result with the start position of the input it consumed.

    p

    a Parser' whose result conforms to Positional'.

    returns

    A parser that has the same behaviour as p', but which marks its result with the start position of the input it consumed, if it didn't already have a position.

    Definition Classes
    Parsers
  47. def rep [T] (p: ⇒ Parser[T]): Parser[List[T]]

    A parser generator for repetitions.

    A parser generator for repetitions.

    rep(p) repeatedly uses p' to parse the input until p' fails (the result is a List of the consecutive results of p')

    p

    a Parser' that is to be applied successively to the input

    returns

    A parser that returns a list of results produced by repeatedly applying p' to the input.

    Definition Classes
    Parsers
  48. def rep1 [T] (first: ⇒ Parser[T], p0: ⇒ Parser[T]): Parser[List[T]]

    A parser generator for non-empty repetitions.

    A parser generator for non-empty repetitions.

    rep1(f, p) first uses f' (which must succeed) and then repeatedly uses p' to parse the input until p' fails (the result is a List' of the consecutive results of f' and p')

    first

    a Parser' that parses the first piece of input

    p0

    a Parser' that is to be applied successively to the rest of the input (if any) -- evaluated at most once, and only when necessary

    returns

    A parser that returns a list of results produced by first applying f' and then repeatedly p' to the input (it only succeeds if f' matches).

    Definition Classes
    Parsers
    Annotations
    @migration
    Migration

    "As of 2.9, the p0 call-by-name arguments is evaluated at most once per constructed Parser object, instead of on every need that arises during parsing."

  49. def rep1 [T] (p: ⇒ Parser[T]): Parser[List[T]]

    A parser generator for non-empty repetitions.

    A parser generator for non-empty repetitions.

    rep1(p) repeatedly uses p' to parse the input until p' fails -- p' must succeed at least once (the result is a List' of the consecutive results of p')

    p

    a Parser' that is to be applied successively to the input

    returns

    A parser that returns a list of results produced by repeatedly applying p' to the input (and that only succeeds if p' matches at least once).

    Definition Classes
    Parsers
  50. def rep1sep [T] (p: ⇒ Parser[T], q: ⇒ Parser[Any]): Parser[List[T]]

    A parser generator for non-empty repetitions.

    A parser generator for non-empty repetitions.

    rep1sep(p, q) repeatedly applies p' interleaved with q' to parse the input, until p' fails. The parser p' must succeed at least once.

    p

    a Parser' that is to be applied successively to the input

    q

    a Parser' that parses the elements that separate the elements parsed by p' (interleaved with q')

    returns

    A parser that returns a list of results produced by repeatedly applying p' to the input (and that only succeeds if p' matches at least once). The results of p' are collected in a list. The results of q' are discarded.

    Definition Classes
    Parsers
  51. def repN [T] (num: Int, p: ⇒ Parser[T]): Parser[List[T]]

    A parser generator for a specified number of repetitions.

    A parser generator for a specified number of repetitions.

    repN(n, p) uses p' exactly n' time to parse the input (the result is a List' of the n' consecutive results of p')

    p

    a Parser' that is to be applied successively to the input

    returns

    A parser that returns a list of results produced by repeatedly applying p' to the input (and that only succeeds if p' matches exactly n' times).

    Definition Classes
    Parsers
  52. def repsep [T] (p: ⇒ Parser[T], q: ⇒ Parser[Any]): Parser[List[T]]

    A parser generator for interleaved repetitions.

    A parser generator for interleaved repetitions.

    repsep(p, q) repeatedly uses p' interleaved with q' to parse the input, until p' fails. (The result is a List' of the results of p'.) Example: <code>repsep(term, ",")</code> parses a comma-separated list of term's, yielding a list of these terms

    p

    a Parser' that is to be applied successively to the input

    q

    a Parser' that parses the elements that separate the elements parsed by p'

    returns

    A parser that returns a list of results produced by repeatedly applying p' (interleaved with q') to the input. The results of p' are collected in a list. The results of q' are discarded.

    Definition Classes
    Parsers
  53. def success [T] (v: T): Parser[T]

    A parser that always succeeds

    A parser that always succeeds

    v

    The result for the parser

    returns

    A parser that always succeeds, with the given result v'

    Definition Classes
    Parsers
  54. def synchronized [T0] (arg0: ⇒ T0): T0

    Attributes
    final
    Definition Classes
    AnyRef
  55. def toString (): String

    Creates a String representation of this object.

    Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, "@", and the object's hashcode in hexadecimal.

    returns

    a String representation of the object.

    Definition Classes
    AnyRef → Any
  56. def wait (): Unit

    Attributes
    final
    Definition Classes
    AnyRef
    Annotations
    @throws()
  57. def wait (arg0: Long, arg1: Int): Unit

    Attributes
    final
    Definition Classes
    AnyRef
    Annotations
    @throws()
  58. def wait (arg0: Long): Unit

    Attributes
    final
    Definition Classes
    AnyRef
    Annotations
    @throws()
  59. def whitespaceChar : Parser[Elem]

    A character-parser that matches a white-space character (and returns it)

Inherited from Tokens

Inherited from Scanners

Inherited from Parsers

Inherited from AnyRef

Inherited from Any