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© 2002-2021 · LAMP/EPFL
scala-parser-combinators/scala.util.parsing.combinator.syntactical/StandardTokenParsers

StandardTokenParsers

scala.util.parsing.combinator.syntactical.StandardTokenParsers
class StandardTokenParsers extends StdTokenParsers

This component provides primitive parsers for the standard tokens defined in StdTokens.

Attributes

Graph
Supertypes
trait Parsers
class Object
trait Matchable
class Any

Members list

Concise view

Type members

Inherited classlikes

case class Error(msg: String, next: Input) extends NoSuccess

The fatal failure case of ParseResult: contains an error-message and the remaining input. No back-tracking is done when a parser returns an Error.

The fatal failure case of ParseResult: contains an error-message and the remaining input. No back-tracking is done when a parser returns an Error.

Attributes

msg

An error message string describing the error.

next

The parser's unconsumed input at the point where the error occurred.

Inherited from:
Parsers
Graph
Supertypes
trait Serializable
trait Product
trait Equals
class NoSuccess
class ParseResult[Nothing]
class Object
trait Matchable
class Any
case class Failure(msg: String, next: Input) extends NoSuccess

The failure case of ParseResult: contains an error-message and the remaining input. Parsing will back-track when a failure occurs.

The failure case of ParseResult: contains an error-message and the remaining input. Parsing will back-track when a failure occurs.

Attributes

msg

An error message string describing the failure.

next

The parser's unconsumed input at the point where the failure occurred.

Inherited from:
Parsers
Graph
Supertypes
trait Serializable
trait Product
trait Equals
class NoSuccess
class ParseResult[Nothing]
class Object
trait Matchable
class Any
sealed abstract class NoSuccess(val msg: String, val next: Input) extends ParseResult[Nothing]

A common super-class for unsuccessful parse results.

A common super-class for unsuccessful parse results.

Attributes

Inherited from:
Parsers
Graph
Supertypes
class ParseResult[Nothing]
class Object
trait Matchable
class Any
Known subtypes
class Error
class Failure
object NoSuccess

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

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

Note: On Scala 2.13, using this extractor leads to an exhaustivity warning:

 def m(r: ParseResult[Int]) = r match {
   case Success(i) => ...
   case NoSuccess(msg, _) => ... // "warning: match may not be exhaustive"

To eliminate this warning, use the irrefutable NoSuccess.I extractor. Due to binary compatibility, NoSuccess itself cannot be changed.

Attributes

Inherited from:
Parsers
Graph
Supertypes
trait Sum
trait Mirror
class Object
trait Matchable
class Any
trait OnceParser[+T] extends Parser[T]

A parser whose ~ combinator disallows back-tracking.

A parser whose ~ combinator disallows back-tracking.

Attributes

Inherited from:
Parsers
Graph
Supertypes
class Parser[T]
trait Input => ParseResult[T]
class Object
trait Matchable
class Any
sealed abstract class ParseResult[+T]

A base class for parser results. A result is either successful or not (failure may be fatal, i.e., an Error, or not, i.e., a Failure). On success, provides a result of type T which consists of some result (and the rest of the input).

A base class for parser results. A result is either successful or not (failure may be fatal, i.e., an Error, or not, i.e., a Failure). On success, provides a result of type T which consists of some result (and the rest of the input).

Attributes

Inherited from:
Parsers
Graph
Supertypes
class Object
trait Matchable
class Any
Known subtypes
class NoSuccess
class Error
class Failure
class Success[T]
abstract class Parser[+T] extends Input => ParseResult[T]

The root class of parsers. Parsers are functions from the Input type to ParseResult.

The root class of parsers. Parsers are functions from the Input type to ParseResult.

Attributes

Inherited from:
Parsers
Graph
Supertypes
trait Input => ParseResult[T]
class Object
trait Matchable
class Any
Known subtypes
trait OnceParser[T]
class PackratParser[T]
case class Success[+T](result: T, next: Input) extends ParseResult[T]

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

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

Attributes

next

The parser's remaining input

result

The parser's output

Inherited from:
Parsers
Graph
Supertypes
trait Serializable
trait Product
trait Equals
class ParseResult[T]
class Object
trait Matchable
class Any
case class ~[+a, +b](_1: a, _2: b)

A wrapper over sequence of matches.

A wrapper over sequence of matches.

Given p1: Parser[A] and p2: Parser[B], a parser composed with p1 ~ p2 will have type Parser[~[A, B]]. The successful result of the parser can be extracted from this case class.

It also enables pattern matching, so something like this is possible:

def concat(p1: Parser[String], p2: Parser[String]): Parser[String] =
  p1 ~ p2 ^^ { case a ~ b => a + b }

Attributes

Inherited from:
Parsers
Graph
Supertypes
trait Serializable
trait Product
trait Equals
class Object
trait Matchable
class Any

Types

type Tokens = StdTokens

Tokens is the abstract type of the Tokens consumed by the parsers in this component.

Tokens is the abstract type of the Tokens consumed by the parsers in this component.

Attributes

Inherited types

type Elem = Token

The input-type for these parsers

The input-type for these parsers

Attributes

Inherited from:
TokenParsers
type Input = Reader[Elem]

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

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

Attributes

Inherited from:
Parsers

Value members

Inherited methods

def OnceParser[T](f: Input => ParseResult[T]): Parser[T] & OnceParser[T]

Attributes

Inherited from:
Parsers
def Parser[T](f: Input => ParseResult[T]): Parser[T]

Attributes

Inherited from:
Parsers
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.

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 accept("name", {case Identifier(n) => Name(n)}) accepts an Identifier(n) and returns a Name(n)

Attributes

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.

Inherited from:
Parsers
def accept[ES](es: ES)(implicit f: ES => List[Elem]): Parser[List[Elem]]

A parser that matches only the given list of element 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.

Attributes

es

the list of expected elements

Returns:

a Parser that recognizes a specified list of elements

Inherited from:
Parsers
def acceptIf(p: Elem => Boolean)(err: Elem => String): Parser[Elem]

A parser matching input elements that satisfy a given predicate.

A parser matching input elements that satisfy a given predicate.

acceptIf(p)(el => "Unexpected "+el) succeeds if the input starts with an element e for which p(e) is true.

Attributes

err

A function from the received element into an error message.

p

A predicate that determines which elements match.

Returns:

A parser for elements satisfying p(e).

Inherited from:
Parsers
def acceptMatch[U](expected: String, f: PartialFunction[Elem, U]): Parser[U]

The parser that matches an element in the domain of the partial function f.

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 acceptMatch("name", {case Identifier(n) => Name(n)}) accepts an Identifier(n) and returns a Name(n)

Attributes

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.

Inherited from:
Parsers
def acceptSeq[ES](es: ES)(implicit f: ES => Iterable[Elem]): Parser[List[Elem]]

A parser that matches only the given scala.collection.Iterable collection of elements es.

A parser that matches only the given scala.collection.Iterable collection of elements es.

acceptSeq(es) succeeds if the input subsequently provides the elements in the iterable es.

Attributes

es

the list of expected elements

Returns:

a Parser that recognizes a specified list of elements

Inherited from:
Parsers
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.

Attributes

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

Inherited from:
Parsers
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.

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.''

Attributes

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

Inherited from:
Parsers
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.

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)

Attributes

combine

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

first

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

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

Inherited from:
Parsers
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).

Attributes

Inherited from:
Parsers
def elem(e: Elem): Parser[Elem]

A parser that matches only the given element e.

A parser that matches only the given element e.

elem(e) succeeds if the input starts with an element e.

Attributes

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).

Inherited from:
Parsers
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.

Attributes

kind

The element kind, used for error messages

p

A predicate that determines which elements match.

Inherited from:
Parsers
def err(msg: String): Parser[Nothing]

A parser that results in an error.

A parser that results in an error.

Attributes

msg

The error message describing the failure.

Returns:

A parser that always fails with the specified error message.

Inherited from:
Parsers
def failure(msg: String): Parser[Nothing]

A parser that always fails.

A parser that always fails.

Attributes

msg

The error message describing the failure.

Returns:

A parser that always fails with the specified error message.

Inherited from:
Parsers
def guard[T](p: => Parser[T]): Parser[T]

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.

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.

Attributes

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

Inherited from:
Parsers
def ident: Parser[String]

A parser which matches an identifier

A parser which matches an identifier

Attributes

Inherited from:
StdTokenParsers
def log[T](p: => Parser[T])(name: String): Parser[T]

A helper method that turns a Parser into one that will print debugging information to stdout before and after being applied.

A helper method that turns a Parser into one that will print debugging information to stdout before and after being applied.

Attributes

Inherited from:
Parsers
def mkList[T]: T ~ List[T] => List[T]

Given a concatenation with a repetition (list), move the concatenated element into the list

Given a concatenation with a repetition (list), move the concatenated element into the list

Attributes

Inherited from:
Parsers
def not[T](p: => Parser[T]): Parser[Unit]

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

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

Attributes

Inherited from:
Parsers
def numericLit: Parser[String]

A parser which matches a numeric literal

A parser which matches a numeric literal

Attributes

Inherited from:
StdTokenParsers
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.

Attributes

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

Inherited from:
Parsers
def phrase[T](p: Parser[T]): Parser[T]

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

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

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

Attributes

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 p consumed all the input.

Inherited from:
Parsers
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.

Attributes

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.

Inherited from:
Parsers
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).

Attributes

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.

Inherited from:
Parsers
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)

Attributes

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).

Inherited from:
Parsers
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)

Attributes

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).

Inherited from:
Parsers
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.

Attributes

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.

Inherited from:
Parsers
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).

Attributes

num

the exact number of times p must succeed

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).

Inherited from:
Parsers
def repNM[T](n: Int, m: Int, p: Parser[T], sep: Parser[Any]): Parser[List[T]]

A parser generator for a specified range of repetitions interleaved by a separator.

A parser generator for a specified range of repetitions interleaved by a separator.

repNM(n, m, p, s) uses p at least n times and up to m times, interleaved with separator s, to parse the input (the result is a List of at least n consecutive results of p and up to m results).

Attributes

m

maximum number of repetitions

n

minimum number of repetitions

p

a Parser that is to be applied successively to the input

sep

a Parser that interleaves with p

Returns:

A parser that returns a list of results produced by repeatedly applying p interleaved with sep to the input. The list has a size between n and up to m (and that only succeeds if p matches at least n times).

Inherited from:
Parsers
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: repsep(term, ",") parses a comma-separated list of term's, yielding a list of these terms.

Attributes

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.

Inherited from:
Parsers
def stringLit: Parser[String]

A parser which matches a string literal

A parser which matches a string literal

Attributes

Inherited from:
StdTokenParsers
def success[T](v: T): Parser[T]

A parser that always succeeds.

A parser that always succeeds.

Attributes

v

The result for the parser

Returns:

A parser that always succeeds, with the given result v

Inherited from:
Parsers

Concrete fields

val lexical: StdLexical

lexical is the component responsible for consuming some basic kind of input (usually character-based) and turning it into the tokens understood by these parsers.

lexical is the component responsible for consuming some basic kind of input (usually character-based) and turning it into the tokens understood by these parsers.

Attributes

Inherited fields

protected val keywordCache: HashMap[String, Parser[String]]

Attributes

Inherited from:
StdTokenParsers

Implicits

Implicits

implicit override def keyword(chars: String): Parser[String]

A parser which matches a single keyword token.

A parser which matches a single keyword token.

Attributes

chars

The character string making up the matched keyword.

Returns:

a Parser that matches the given string

Definition Classes

Inherited implicits

implicit def accept(e: Elem): Parser[Elem]

A parser that matches only the given element e.

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 Tokens, Identifier("new") (which is a Token) can be used directly, instead of first creating a Parser using accept(Identifier("new")).

Attributes

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.

Inherited from:
Parsers
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© 2002-2021 · LAMP/EPFL
© 2002-2021 · LAMP/EPFL