package implicits
This package contains various functionality that involve Scala's implicits mechanism.
This includes conversions from scala literals into parsers, as well as enabling new syntax
on regular Scala values (such as Parsley's lift
or zipped
syntax).
Automatic conversion to Parsley[Unit]
is also supported within this package.
- Source
- package.scala
- Alphabetic
- By Inheritance
- implicits
- AnyRef
- Any
- Hide All
- Show All
- Public
- Protected
Value Members
- object character
Provides implicit conversions for characters and strings into parsers.
Provides implicit conversions for characters and strings into parsers.
The use of
char
andstring
can be distracting to the overall structure of the parser with respect to the grammar. This module exposes combinators that can implicitly convert Scala's string and character literals so that they represent parsers. These will not be whitespace sensitive.- Since
3.0.0
- object combinator
Provides implicit conversions for parsers into unit parsers, and other implicits involving combinators.
Provides implicit conversions for parsers into unit parsers, and other implicits involving combinators.
- Since
3.0.0
- object lift
This module provides the "
lift
syntax", which enables alift
combinator on functions of arities up to 22, applying the function across the results of several parsers.This module provides the "
lift
syntax", which enables alift
combinator on functions of arities up to 22, applying the function across the results of several parsers.scala> import parsley.character.char scala> import parsley.implicits.lift.{Lift2, Lift3} scala> case class Add(x: Int, y: Int) scala> val p = Add.lift(char('a').as(4), char('b').as(5)) scala> p.parse("ab") val res0 = Success(Add(4, 5)) scala> val f = (x: Int, y: Int, z: Int) => x * y + z scala> val q = f.lift(char('a').as(3), char('b').as(2), char('c').as(5)) scala> q.parse("abc") val res1 = Success(11) scala> q.parse("ab") val res2 = Failure(..)
- Since
3.0.0
- Note
a limitation of this syntax is that it requires the function's type to be fully known. For a version of this syntax that behaves better with type inference, see
zipped
.
Example: - object zipped
This module provides alternatives to the
f.lift(x, y)
syntax,(x, y).zipped(f)
, which works better with type inference.This module provides alternatives to the
f.lift(x, y)
syntax,(x, y).zipped(f)
, which works better with type inference.Also enables a parameterless
zipped
method, to pair an arbitrary number of parsers such that(p, q).zipped = p.zip(q)
.Thanks to Andrei Gramescu and George Stacey for ensuring that these combinators even exist in the first place.
scala> import parsley.character.char scala> import parsley.implicits.zipped.{Zipped2, Zipped3} scala> case class Add(x: Int, y: Int) scala> val p = (char('a').as(4), char('b').as(5)).zipped(Add) scala> p.parse("ab") val res0 = Success(Add(4, 5)) scala> val q = (char('a').as(3), char('b').as(2), char('c').as(5)).zipped((x, y, z) => x * y + z) scala> q.parse("abc") val res1 = Success(11) scala> q.parse("ab") val res2 = Failure(..)
- Since
3.0.0
- Note
these methods are not lazy like the
lift
syntax orliftN
functions! Use the prefix~
combinator to make arguments lazy where necessary.
Example:
This is the documentation for Parsley.
Package structure
The parsley package contains the
Parsley
class, as well as theResult
,Success
, andFailure
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 parsingparsley.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 inchain
.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 aParsley[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 implementingunexpectedToken
in theErrorBuilder
.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 theLexer
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.