Packages

•  package root

  This is the documentation for Parsley.

  This is the documentation for Parsley.

  Package structure

  The parsley package contains the Parsley class, as well as the Result, Success, and Failure types. In addition to these, it also contains the following packages and "modules" (a module is defined as being an object which mocks a package):

  • parsley.Parsley contains the bulk of the core "function-style" combinators.
  • parsley.combinator contains many helpful combinators that simplify some common parser patterns.
  • parsley.character contains the combinators needed to read characters and strings, as well as combinators to match specific sub-sets of characters.
  • parsley.debug contains debugging combinators, helpful for identifying faults in parsers.
  • parsley.extension contains syntactic sugar combinators exposed as implicit classes.
  • parsley.io contains extension methods to run parsers with input sourced from IO sources.
  • parsley.expr contains the following sub modules:
    • parsley.expr.chain contains combinators used in expression parsing
    • parsley.expr.precedence is a builder for expression parsers built on a precedence table.
    • parsley.expr.infix contains combinators used in expression parsing, but with more permissive types than their equivalents in chain.
    • parsley.expr.mixed contains combinators that can be used for expression parsing, but where different fixities may be mixed on the same level: this is rare in practice.
  • parsley.implicits contains several implicits to add syntactic sugar to the combinators. These are sub-categorised into the following sub modules:
    • parsley.implicits.character contains implicits to allow you to use character and string literals as parsers.
    • parsley.implicits.combinator contains implicits related to combinators, such as the ability to make any parser into a Parsley[Unit] automatically.
    • parsley.implicits.lift enables postfix application of the lift combinator onto a function (or value).
    • parsley.implicits.zipped enables boths a reversed form of lift where the function appears on the right and is applied on a tuple (useful when type inference has failed) as well as a .zipped method for building tuples out of several combinators.
  • parsley.errors contains modules to deal with error messages, their refinement and generation.
    • parsley.errors.combinator provides combinators that can be used to either produce more detailed errors as well as refine existing errors.
    • parsley.errors.tokenextractors provides mixins for common token extraction strategies during error message generation: these can be used to avoid implementing unexpectedToken in the ErrorBuilder.
  • parsley.lift contains functions which lift functions that work on regular types to those which now combine the results of parsers returning those same types. these are ubiquitous.
  • parsley.ap contains functions which allow for the application of a parser returning a function to several parsers returning each of the argument types.
  • parsley.registers contains combinators that interact with the context-sensitive functionality in the form of registers.
  • parsley.token contains the Lexer class that provides a host of helpful lexing combinators when provided with the description of a language.
  • parsley.position contains parsers for extracting position information.
  • parsley.genericbridges contains some basic implementations of the Parser Bridge pattern (see Design Patterns for Parser Combinators in Scala, or the parsley wiki): these can be used before more specialised generic bridge traits can be constructed.

  Definition Classes

  root

•  package parsley

  Definition Classes

  root

•  package token

  This package provides a wealth of functionality for performing common lexing tasks.

  This package provides a wealth of functionality for performing common lexing tasks.

  It is organised as follows:

  • the main parsing functionality is accessed via Lexer, which provides implementations for the combinators found in the sub-packages given a LexicalDesc.
  • the descriptions sub-package is how a lexical structure can be described, providing the configuration that alters the behaviour of the parsers produced by the Lexer.
  • the other sub-packages contain the high-level interfaces that the Lexer exposes, which can be used to pass whitespace-aware and non-whitespace-aware combinators around in a uniform way.
  • the predicate module contains functionality to help define boolean predicates on characters or unicode codepoints.

  Definition Classes

  parsley

•  class Lexer extends AnyRef

  This class provides a large selection of functionality concerned with lexing.

  This class provides a large selection of functionality concerned with lexing.

  This class provides lexing functionality to parsley, however it is guaranteed that nothing in this class is not implementable purely using parsley's pre-existing functionality. These are regular parsers, but constructed in such a way that they create a clear and logical separation from the rest of the parser.

  The class is broken up into several internal "modules" that group together similar kinds of functionality. Importantly, the lexemes and nonlexemes objects separate the underlying token implementations based on whether or not they consume whitespace or not. Functionality is broadly duplicated across both of these modules: lexemes should be used by a wider parser, to ensure whitespace is handled uniformly; and nonlexemes should be used to define further composite tokens or in special circumstances where whitespace should not be consumed.

  It is possible that some of the implementations of parsers found within this class may have been hand-optimised for performance: care will have been taken to ensure these implementations precisely match the semantics of the originals.

  Definition Classes

  token

  Annotations

  @deprecatedInheritance()

•  object nonlexeme

  This object is concerned with non-lexemes: these are tokens that do not give any special treatment to whitespace.

  This object is concerned with non-lexemes: these are tokens that do not give any special treatment to whitespace.

  Whilst the functionality in lexeme is strongly recommended for wider use in a parser, the functionality here may be useful for more specialised use-cases. In particular, these may for the building blocks for more complex tokens (where whitespace is not allowed between them, say), in which case these compound tokens can be turned into lexemes manually. For example, the lexer does not have configuration for trailing specifiers on numeric literals (like, 1024L in Scala, say): the desired numeric literal parser could be extended with this functionality before whitespace is consumed by using the variant found in this object.

  Alternatively, these tokens can be used for lexical extraction, which can be performed by the ErrorBuilder typeclass: this can be used to try and extract tokens from the input stream when an error happens, to provide a more informative error. In this case, it is desirable to not consume whitespace after the token to keep the error tight and precise.

  Definition Classes

  Lexer

  Since

  4.0.0

• numeric
• text

parsley.token.Lexer.nonlexeme

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