trait Parser[-In, +Out] extends AnyRef
Primary "spac" abstraction which represents a sink for data events.
Parsers are responsible for interpreting a stream of In
events as a single result of type Out
.
The actual interpretation is performed by a Parser.Handler
which the Parser is responsible for constructing.
Handlers may be internally-mutable, and so they are generally only constructed by the parse
helper methods or by other handlers.
Parsers themselves are immutable, acting as "handler factories", and so they may be freely reused.
A parser differs from typical "fold" operations in that it may choose to abort early with a result, leaving the remainder of the data stream untouched.
- In
event/input type
- Out
result type
- Self Type
- Parser[In, Out]
- Source
- Parser.scala
- Grouped
- Alphabetic
- By Inheritance
- Parser
- AnyRef
- Any
- by ParserFollowedByOps
- by InvariantOps
- by any2stringadd
- by StringFormat
- by Ensuring
- by ArrowAssoc
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- Public
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Abstract Value Members
Concrete Value Members
- final def !=(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
- final def ##: Int
- Definition Classes
- AnyRef → Any
- def +(other: String): String
- def ->[B](y: B): (Parser[In, Out], B)
- final def ==(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
- final def asInstanceOf[T0]: T0
- Definition Classes
- Any
- def asTransformer: Transformer[In, Out]
Represent this parser as a
Transformer
which emits this parser's result - def attempt: Parser[In, Either[Throwable, Out]]
Like
wrapSafe
, but represents exceptions asLeft
and successful results asRight
- def beforeContext[I2 <: In, StackElem](matcher: ContextMatcher[StackElem, Any])(implicit stackable: StackLike[I2, StackElem], pos: CallerPos): Parser[I2, Out]
Specialization of
interruptedBy
for stack-like input types, such that an interruption will occur upon entering a stack context that can be matched by the givenmatcher
.Specialization of
interruptedBy
for stack-like input types, such that an interruption will occur upon entering a stack context that can be matched by the givenmatcher
.Example:
val preludeContext = * \ "prelude" val dataContext = * \ "data" for { prelude <- Splitter(preludeContext).firstOption[Prelude].beforeContext(dataContext).followedByStream data <- Splitter(dataContext).as[Data] } yield data
- I2
Subtype of
In
, or justIn
(to satisfy contravariance of Parser'sIn
type)- StackElem
Specialization of the
In
type for when it represents a stack push or pop- matcher
A matching function that operates on a context stack
- stackable
Interprets the inputs as stack push/pop events to accumulate a context stack
- returns
A parser which will perform an early
finish()
when a matching context is encountered
- def clone(): AnyRef
- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.CloneNotSupportedException]) @native()
- def ensuring(cond: (Parser[In, Out]) => Boolean, msg: => Any): Parser[In, Out]
- def ensuring(cond: (Parser[In, Out]) => Boolean): Parser[In, Out]
- def ensuring(cond: Boolean, msg: => Any): Parser[In, Out]
- def ensuring(cond: Boolean): Parser[In, Out]
- final def eq(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
- def equals(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef → Any
- def expectInputs[I2 <: In](expectations: List[(String, (I2) => Boolean)]): Parser[I2, Out]
Impose expectations on the sequence of inputs to be received by handlers created by this parser.
Impose expectations on the sequence of inputs to be received by handlers created by this parser. As this parser's handler receives an input, the input will be tested against the head of the expectations list. If the test returns
false
, the expectation is failed and the handler will throw an exception. If the test returnstrue
, the expectation is satisfied, and the handler will advance to the next expectation. If there are no more expectations left in the list (i.e. N inputs have satisfied the corresponding N expectations), then all expectations have been met and inputs will be treated as normal by the handler. If the handler receives an EOF before all expectations are met, it will throw an exception.- expectations
A sequence of
label -> test
expectations imposed on inputs to this parser- returns
A copy of this parser with expectations imposed on its inputs
- def finalize(): Unit
- Attributes
- protected[lang]
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.Throwable])
- def followedBy: FollowedBy[In, Out, Parser]
Intermediate object for creating a sequenced parser in which the result of this parser will be used to initialize a second parser as soon as it is available.
Intermediate object for creating a sequenced parser in which the result of this parser will be used to initialize a second parser as soon as it is available.
In other words, the source (series of
In
values) will be fed into this Parser until this parser's handler returns a result of typeOut
. At that point, the second parser (as specified by using theapply
orflatMap
methods on theFollowedBy
returned by this method) will be instantiated. Any relevant "stack events" (seeStackable
) will be replayed so the second parser has the right context, and from that point on, allIn
values will be sent to the second parser. When that second parser returns a result, that result becomes the output of the combined parser created bythis.followedBy(out => makeSecondParser(out))
Examples:
val p1: Parser[A] = /* ... */ def getP2(p1Result: A): Parser[B] = /* ... */ val combined: Parser[B] = p1.followedBy(getP2) // alternative `flatMap` syntax val combined: Parser[B] = for { p1Result <- p1.followedBy p2Result <- getP2(p1Result) } yield p2Result
See Parser's
interruptedBy
, which is useful when atransformer.parseFirstOption
must befollowedBy
some other parser.- Implicit
- This member is added by an implicit conversion from Parser[In, Out] toParserFollowedByOps[In, Out] performed by method ParserFollowedByOps in io.dylemma.spac.Parser.
- Definition Classes
- ParserFollowedByOps
- def followedByParser: FollowedBy[In, Out, Parser]
Alias for
followedBy
, for use when Cat'sApplyOps
gets in the way with its own uselessfollowedBy
method.Alias for
followedBy
, for use when Cat'sApplyOps
gets in the way with its own uselessfollowedBy
method.- Implicit
- This member is added by an implicit conversion from Parser[In, Out] toParserFollowedByOps[In, Out] performed by method ParserFollowedByOps in io.dylemma.spac.Parser.
- Definition Classes
- ParserFollowedByOps
- def followedByStream: FollowedBy[In, Out, Transformer]
Intermediate object creating a transformer that depends on this parser.
Intermediate object creating a transformer that depends on this parser. Particularly useful in cases where one or more specific "info" elements precede a stream of other elements which require that "info" to be parsed.
Examples:
val p1: Parser[In, A] = /* ... */ def getP2Stream(p1Result: A): Transformer[In, B] = /* ... */ val combined: Transformer[In, B] = p1.andThenStream(getP2Stream) // alternative `flatMap` syntax val combined: Transformer[In, B] = for { p1Result <- p1.andThenStream p2Result <- getP2Stream(p1Result) } yield p2Result
See
followedBy
for a general explanation of how the combination works.See also,
interruptedBy
, which is useful when atransformer.parseFirstOption
must befollowedBy
some other transformer.- Implicit
- This member is added by an implicit conversion from Parser[In, Out] toParserFollowedByOps[In, Out] performed by method ParserFollowedByOps in io.dylemma.spac.Parser.
- Definition Classes
- ParserFollowedByOps
- def formatted(fmtstr: String): String
- final def getClass(): Class[_ <: AnyRef]
- Definition Classes
- AnyRef → Any
- Annotations
- @native()
- def hashCode(): Int
- Definition Classes
- AnyRef → Any
- Annotations
- @native()
- def interruptedBy[I2 <: In](interrupter: Parser[I2, Any]): Parser[I2, Out]
Create a copy of this parser that will treat a result from the
interrupter
as an early EOF.Create a copy of this parser that will treat a result from the
interrupter
as an early EOF. This is especially useful for creatingfollowedBy
chains involving optional elements.Normally, a parser for an optional item in some context will not finish until that context ends, or until the item is encountered. So if the item is not present,
followedBy
logic won't work since thefollowUp
parser/transformer will not see any events.To make sure the leading parser can "fail fast", you can "interrupt" it, typically by creating a parser that immediately returns a result upon entering a particular context, i.e. the context in which the "following" parser will start.
Parser#beforeContext
provides a convenience for doing so.Note that if the
interrupter
throws an exception, that exception will not be caught. If your interrupter might throw, passinterrupter.wrapSafe
instead to swallow the exception.- I2
Subtype of
In
, or justIn
(to satisfy contravariance of Parser'sIn
type)- interrupter
A parser which will be run in parallel with this parser, and whose result will be treated as an early EOF for this parser, forcing an early call to
finish()
.- returns
A parser which will perform an early
finish()
call when theinterrupter
produces a result.
- final def isInstanceOf[T0]: Boolean
- Definition Classes
- Any
- def map[Out2](f: (Out) => Out2): Parser[In, Out2]
Create a copy of this Parser whose result is transformed by the given function
f
.Create a copy of this Parser whose result is transformed by the given function
f
.- Out2
The new parser's result type
- f
Result transformation function
- final def ne(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
- final def notify(): Unit
- Definition Classes
- AnyRef
- Annotations
- @native()
- final def notifyAll(): Unit
- Definition Classes
- AnyRef
- Annotations
- @native()
- def orElse[In2 <: In, Out2 >: Out](fallback: Parser[In2, Out2]): Parser[In2, Out2]
Combine this parser with the
fallback
such that failures from the underlying parsers will be ignored as long as at least one succeeds.Combine this parser with the
fallback
such that failures from the underlying parsers will be ignored as long as at least one succeeds. The result will be the result of whichever underlying parser succeeds first. If all of the underlying parsers fail, aSpacException.FallbackChainFailure
will be thrown by the returned parser's handler.- In2
Subtype of
In
, or justIn
(to satisfy Parser's contravariance on theIn
type)- Out2
Supertype of
Out
, or justOut
(to satisfy Parser's covariance on theOut
type)- fallback
another parser of the same(ish) type as this one
- returns
A new parser that will succeed if either this parser or the fallback succeed
- def parse[S](source: S)(implicit S: Parsable[Id, S, In], pos: CallerPos): Out
Interpret the given
source
as a data stream of typeIn
, using this parser to produce a result of typeOut
.Interpret the given
source
as a data stream of typeIn
, using this parser to produce a result of typeOut
. Exceptions thrown by the underlying parser logic will bubble up and be thrown by this method.- S
The source type. Will typically be a
File
or aList[In]
.- source
The source of a data stream
- S
Typeclass instance that provides the logic for feeding values from
source
into this parser- pos
Captures the caller filename and line number, used to fill in the 'spac trace' if the parser throws an exception
- Annotations
- @throws(scala.this.throws.<init>$default$1[io.dylemma.spac.SpacException[_]])
- def parseF[F[_], S](source: S)(implicit S: Parsable[F, S, In], pos: CallerPos): F[Out]
Interpret the given
source
as a data stream of typeIn
, using this parser to produce a result of typeOut
.Interpret the given
source
as a data stream of typeIn
, using this parser to produce a result of typeOut
. In this version of theparse
method, the data-pull and handler logic is run in theF
context. Exceptions thrown by the underlying parser logic will be raised in the F context instead of thrown.- F
An effect type in which the data-pull and handler logic will be run
- S
The source type. Will typically be a
File
or aList[In]
.- source
The source of a data stream
- S
Typeclass instance that provides the logic for feeding values from
source
into this parser- pos
Captures the caller filename and line number, used to fill in the 'spac trace' if the parser throws an exception
- returns
An effect which, when evaluated, will consume data events from the
source
using this parser to produce a result. Note that if theF
type isn't "lazy", the actual evaluation of the stream may happen as part of the *construction* of theF[Out]
, rather than during the *evaluation*.
- Implicit
- This member is added by an implicit conversion from Parser[In, Out] toInvariantOps[In, Out] performed by method InvariantOps in io.dylemma.spac.Parser.
- Definition Classes
- InvariantOps
- def rethrow[T](implicit ev: <:<[Out, Either[Throwable, T]]): Parser[In, T]
Like
unwrapSafe
, but rethrows exceptions fromLeft
or returns results fromRight
.Like
unwrapSafe
, but rethrows exceptions fromLeft
or returns results fromRight
. This operation is the opposite ofattempt
. - final def synchronized[T0](arg0: => T0): T0
- Definition Classes
- AnyRef
- def toPipe[F[_]](implicit pos: CallerPos): Pipe[F, In, Out]
Convert this parser to a FS2 "Pipe".
Convert this parser to a FS2 "Pipe". The resulting pipe will forward inputs from the upstream into this parser, emitting a single value to the downstream when this parser finishes. Since a
Parser
may abort early (e.g. withParser.first
), the pipe may not pull the entire input stream. - def toString(): String
- Definition Classes
- AnyRef → Any
- def unwrapSafe[T](implicit ev: <:<[Out, Try[T]]): Parser[In, T]
Creates a copy of this parser which unwraps the resulting
Try
, throwing an exception if the result was aFailure
.Creates a copy of this parser which unwraps the resulting
Try
, throwing an exception if the result was aFailure
. This operation is the opposite ofwrapSafe
. - def upcast[Out2](implicit ev: <:<[Out, Out2]): Parser[In, Out2]
Returns this parser, with the output type widened to
Out2
, which is some supertype ofOut
.Returns this parser, with the output type widened to
Out2
, which is some supertype ofOut
. UsesasInstanceOf
rather than creating a new parser. - final def wait(): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
- final def wait(arg0: Long, arg1: Int): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException])
- final def wait(arg0: Long): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws(classOf[java.lang.InterruptedException]) @native()
- def withName(name: String): Parser[In, Out]
Creates a copy of this parser, but with a different
toString
Creates a copy of this parser, but with a different
toString
- name
The new "name" (i.e.
toString
) for this parser- returns
A copy of this parser whose
toString
returns the givenname
- def wrapSafe: Parser[In, Try[Out]]
Create a copy of this Parser whose handler will catch NonFatal exceptions thrown by the underlying logic.
Create a copy of this Parser whose handler will catch NonFatal exceptions thrown by the underlying logic. Caught exceptions will be yielded as a
Failure
output. Normal results will be wrapped inSuccess
.- returns
A copy of this parser that will return a
Failure
instead of throwing exceptions
Deprecated Value Members
- def →[B](y: B): (Parser[In, Out], B)
- Implicit
- This member is added by an implicit conversion from Parser[In, Out] toArrowAssoc[Parser[In, Out]] performed by method ArrowAssoc in scala.Predef.
- Definition Classes
- ArrowAssoc
- Annotations
- @deprecated
- Deprecated
(Since version 2.13.0) Use
->
instead. If you still wish to display it as one character, consider using a font with programming ligatures such as Fira Code.