Packages

  • package root
    Definition Classes
    root
  • package parsley
    Definition Classes
    root
  • package errors

    This package contains various functionality relating to the generation and formatting of error messages.

    This package contains various functionality relating to the generation and formatting of error messages.

    In particular, it includes a collection of combinators for improving error messages within the parser, including labelling and providing additional information. It also contains combinators that can be used to valid data produced by a parser, to ensure it conforms to expected invariances, producing good quality error messages if this is not the case. Finally, this package contains ways of changing the formatting of error messages: this can either be changing how the default String-based errors are formatted, or by injectiing Parsley's errors into a custom error object.

    Definition Classes
    parsley
  • package tokenextractors

    This package contains implementations of token extractors that can be mixed into ErrorBuilder to decide how to extract unexpected tokens from the residual input left over from a parse error.

    This package contains implementations of token extractors that can be mixed into ErrorBuilder to decide how to extract unexpected tokens from the residual input left over from a parse error.

    These are common strategies, and something here is likely to be what is needed. They are all careful to handle unprintable characters and whitespace in a sensible way, and account for unicode codepoints that are wider than a single 16-bit character.

    Definition Classes
    errors
    Since

    4.0.0

  • DefaultErrorBuilder
  • ErrorBuilder
  • Token
  • TokenSpan
  • combinator
c

parsley.errors

DefaultErrorBuilder

abstract class DefaultErrorBuilder extends ErrorBuilder[String]

This class us used to build Parsley's default error messages.

While it compiles with the ErrorBuilder typeclass, it should not be considered a stable contract: the formatting can be changed at any time and without notice. The API, however, will remain stable.

Source
DefaultErrorBuilder.scala
Since

3.0.0

Note

this class is abstract as it does not implement unexpectedToken: when creating an instance mix-in an appropriate token extractor from parsley.errors.tokenextractors.

Linear Supertypes
ErrorBuilder[String], AnyRef, Any
Ordering
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Inherited
  1. DefaultErrorBuilder
  2. ErrorBuilder
  3. AnyRef
  4. Any
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Visibility
  1. Public
  2. All

Instance Constructors

  1. new DefaultErrorBuilder()

Type Members

  1. type EndOfInput = String

    Represents the end of the input.

    Represents the end of the input.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  2. type ErrorInfoLines = Seq[String]

    The representation type of the main body within the error message.

    The representation type of the main body within the error message.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  3. type ExpectedItems = Option[String]

    The representation of all the different possible tokens that could have prevented an error.

    The representation of all the different possible tokens that could have prevented an error.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  4. type ExpectedLine = Option[String]

    The representation of the information regarding the solving tokens.

    The representation of the information regarding the solving tokens.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  5. type Item = String

    The base type of Raw, Named and EndOfInput that represents the individual items within the error.

    The base type of Raw, Named and EndOfInput that represents the individual items within the error.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  6. type LineInfo = Seq[String]

    The representation of the line of input where the error occurred.

    The representation of the line of input where the error occurred.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  7. type Message = String

    The representation of a reason or a message generated by the parser.

    The representation of a reason or a message generated by the parser.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  8. type Messages = Seq[Message]

    The representation of the combined reasons or failure messages from the parser.

    The representation of the combined reasons or failure messages from the parser.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  9. type Named = String

    This represents "named" tokens, which have been provided with a label.

    This represents "named" tokens, which have been provided with a label.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  10. type Position = String

    The representation type of position information within the generated message.

    The representation type of position information within the generated message.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  11. type Raw = String

    This represents "raw" tokens, where are those without labels: they come direct from the input, or the characters that the parser is trying to read.

    This represents "raw" tokens, where are those without labels: they come direct from the input, or the characters that the parser is trying to read.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  12. type Source = Option[String]

    The representation of the file information.

    The representation of the file information.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  13. type UnexpectedLine = Option[String]

    The representation of the information regarding the problematic token.

    The representation of the information regarding the problematic token.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder

Abstract Value Members

  1. abstract def unexpectedToken(cs: Iterable[Char], amountOfInputParserWanted: Int, lexicalError: Boolean): Token

    Extracts an unexpected token from the remaining input.

    Extracts an unexpected token from the remaining input.

    When a parser fails, by default an error reports an unexpected token of a specific width. This works well for some parsers, but often it is nice to have the illusion of a dedicated lexing pass: instead of reporting the next few characters as unexpected, an unexpected token can be reported instead. This can take many forms, for instance trimming the token to the next whitespace, only taking one character, or even trying to lex a token out of the stream.

    This method can be easily implemented by mixing in an appropriate token extractor from parsley.errors.tokenextractors into this builder.

    cs

    the remaining input at point of failure (this is guaranteed to be non-empty)

    amountOfInputParserWanted

    the input the parser tried to read when it failed (this is not guaranteed to be smaller than the length of cs)

    lexicalError

    was this error generated as part of "lexing", or in a wider parser (see markAsToken)

    returns

    a token extracted from cs that will be used as part of the unexpected message.

    Definition Classes
    ErrorBuilder
    Since

    4.0.0

Concrete Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. final def ##(): Int
    Definition Classes
    AnyRef → Any
  3. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  4. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  5. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()
  6. def combineExpectedItems(alts: Set[Item]): ExpectedItems

    Details how to combine the various expected items into a single representation.

    Details how to combine the various expected items into a single representation.

    alts

    The possible items that fix the error

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  7. def combineMessages(alts: Seq[Message]): Messages

    Details how to combine any reasons or messages generated within a single error.

    Details how to combine any reasons or messages generated within a single error. Reasons are used by vanilla messages and messages are used by specialised messages.

    alts

    the messages to combine (see the message or reason methods).

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  8. val endOfInput: EndOfInput

    Value that represents the end of the input in the error message.

    Value that represents the end of the input in the error message.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  9. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  10. def equals(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  11. def expected(alts: ExpectedItems): ExpectedLine

    Describes how to handle the information about the tokens that could have avoided the error.

    Describes how to handle the information about the tokens that could have avoided the error.

    alts

    the tokens that could have prevented the error (see the combineExpectedItems method).

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  12. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
  13. def format(pos: Position, source: Source, lines: ErrorInfoLines): String

    This is the top level function, which finally compiles all the formatted sub-parts into a finished value of type Err.

    This is the top level function, which finally compiles all the formatted sub-parts into a finished value of type Err.

    pos

    this is the representation of the position of the error in the input (see the pos method).

    source

    this is the representation of the filename, if it exists (see the source method).

    lines

    this is the main body of the error message (see vanillaError or specialisedError methods).

    returns

    the final assembled error message.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  14. final def getClass(): Class[_]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  15. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  16. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  17. def lineInfo(line: String, linesBefore: Seq[String], linesAfter: Seq[String], errorPointsAt: Int, errorWidth: Int): LineInfo

    Describes how to format the information about the line that the error occured on.

    Describes how to format the information about the line that the error occured on.

    line

    the full line of input that produced this error message.

    linesBefore

    the lines of input just before the one that produced this message (up to numLinesBefore).

    linesAfter

    the lines of input just after the one that produced this message (up to numLinesAfter).

    errorPointsAt

    the offset into the line that the error points at.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  18. def message(msg: String): Message

    Describes how to represent the messages produced by the fail combinator (or any that are implemented using it).

    Describes how to represent the messages produced by the fail combinator (or any that are implemented using it).

    msg

    the message produced by the parser.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  19. def named(item: String): Named

    Formats a named item generated by a label.

    Formats a named item generated by a label.

    item

    the name given to the label.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  20. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  21. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  22. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  23. val numLinesAfter: Int

    The number of lines of input to request after an error occured.

    The number of lines of input to request after an error occured.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  24. val numLinesBefore: Int

    The number of lines of input to request before an error occured.

    The number of lines of input to request before an error occured.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  25. def pos(line: Int, col: Int): Position

    Formats a position into the representation type given by Position.

    Formats a position into the representation type given by Position.

    line

    the line the error occurred at.

    col

    the column the error occurred at.

    returns

    a representation of the position.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  26. def raw(item: String): Raw

    Formats a raw item generated by either the input string or a input reading combinator without a label.

    Formats a raw item generated by either the input string or a input reading combinator without a label.

    item

    the raw, unprocessed input.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  27. def reason(reason: String): Message

    Describes how to represent the reasons behind a parser fail.

    Describes how to represent the reasons behind a parser fail. These reasons originate from the explain combinator.

    reason

    the reason produced by the parser.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  28. def source(sourceName: Option[String]): Source

    Formats the name of the file if it exists into the type give by Source

    Formats the name of the file if it exists into the type give by Source

    sourceName

    the source name of the file, if any.

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  29. def specialisedError(msgs: Messages, lines: LineInfo): ErrorInfoLines

    Specialised errors are triggered by fail and any combinators that are implemented in terms of fail.

    Specialised errors are triggered by fail and any combinators that are implemented in terms of fail. These errors take precedence over the vanilla errors, and contain less, more specialised, information

    msgs

    information detailing the error (see the combineMessages method).

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  30. final def synchronized[T0](arg0: ⇒ T0): T0
    Definition Classes
    AnyRef
  31. def toString(): String
    Definition Classes
    AnyRef → Any
  32. def unexpected(item: Option[Item]): UnexpectedLine

    Describes how to handle the (potentially missing) information about what token(s) caused the error.

    Describes how to handle the (potentially missing) information about what token(s) caused the error.

    item

    The Item that caused this error

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  33. def vanillaError(unexpected: UnexpectedLine, expected: ExpectedLine, reasons: Messages, lines: LineInfo): ErrorInfoLines

    Vanilla errors are those produced such that they have information about both expected and unexpected tokens.

    Vanilla errors are those produced such that they have information about both expected and unexpected tokens. These are usually the default, and are not produced by fail (or any derivative) combinators.

    unexpected

    information about which token(s) caused the error (see the unexpected method).

    expected

    information about which token(s) would have avoided the error (see the expected method).

    reasons

    additional information about why the error occured (see the combineMessages method).

    Definition Classes
    DefaultErrorBuilder → ErrorBuilder
  34. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  35. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  36. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws( ... ) @native()

Inherited from ErrorBuilder[String]

Inherited from AnyRef

Inherited from Any

Top-Level Formatting

These methods help assembly the final products of the error messages. The format method will return the desired Err types, whereas specialisedError and vanillaError both assemble an ErrorInfoLines that the format method can consume.

Error Preamble

These methods control the formatting of the preamble of an error message, which is the position and source info. These are then consumed by format itself.

Contextual Input Lines

These methods control how many lines of input surrounding the error are requested, and direct how these should be put together to form a LineInfo.

Shared Components

These methods control any components or structure shared by both types of messages. In particular, the representation of reasons and messages is shared, as well as how they are combined together to form a unified block of content lines.

Specialised-Specific Components

These methods control the Specialised-specific components, namely the formatting of a bespoke error message.

Vanilla-Specific Components

These methods control the Vanilla-specific error components, namely how expected error items should be combined, how to format the unexpected line, and how to format reasons generated from explain.

Error Items

These methods control how error items within Vanilla errors are formatted. These are either the end of input, a named label generated by the label combinator, or a raw piece of input intrinsically associated with a combinator.

Ungrouped