Packages

  • package root
    Definition Classes
    root
  • package io
    Definition Classes
    root
  • package dylemma
    Definition Classes
    io
  • package spac

    SPaC (short for "Streaming Parser Combinators") is a library for building stream consumers in a declarative style, specialized for tree-like data types like XML and JSON.

    SPaC (short for "Streaming Parser Combinators") is a library for building stream consumers in a declarative style, specialized for tree-like data types like XML and JSON.

    Many utilities for handling XML and JSON data involve parsing the entire "document" to some DOM model, then inspecting and transforming that model to extract information. The downside to these utilities is that when the document is very large, the DOM may not fit in memory. The workaround for this type of problem is to treat the document as a stream of "events", e.g. "StartElement" and "EndElement" for XML, or "StartObject" and "EndObject" for JSON. The downside to this workaround is that writing code to handle these streams can be complicated and error-prone, especially when the DOM is complicated.

    SPaC's goal is to drastically simplify the process of creating code to handle these streams.

    This package contains the "core" SPaC traits; Parser, Transformer, Splitter, and ContextMatcher.

    See the xml and json subpackages (provided by the xml-spac and json-spac libraries respectively) for specific utilities related to handling XML and JSON event streams.

    Definition Classes
    dylemma
  • package interop
    Definition Classes
    spac
  • package json

    This package provides extensions to the core "spac" library which allow for the handling of JSON data.

    This package provides extensions to the core "spac" library which allow for the handling of JSON data.

    Rather than creating explicit classes that extend Parser, Transformer, and Splitter, this package provides type aliases and implicit extensions. For example, JsonParser[A] is just a type alias for Parser[JsonEvent, A], and JsonParser is just a call to Parser[JsonEvent].

    Implicit JsonParsers are available for each of the JSON primitive types:

    • string
    • number (expressed as Int, Long, Float, or Double)
    • boolean
    • null (expressed as None.type)

    Helpers are available for parsing JSON arrays and objects:

    • JsonParser.listOf[A] to parse an array where each value is an A
    • JsonParser.objectOf[A] to parse an object where the value for each field an A
    • JsonParser.objectOfNullable[A] to parse an object where the value for each field is either null or an A, filtering out the nulls
    • JsonParser.fieldOf[A](fieldName) to parse a specific field from an object

    A DSL for creating json-specific ContextMatchers is provided to make it more convenient to call Splitter.json. For example:

    Splitter.json("foo" \ "bar").as[String].parseFirst

    Can be used to capture rootJson.foo.bar as a String in

    {
      "foo": {
        "bar": "hello"
      }
    }

    To "split" values inside arrays, index-related context matchers are available, e.g.

    Splitter.json("foo" \ anyIndex).as[Int].parseToList

    Can be used to capture each of the numbers in the "foo" array in

    {
      "foo": [1, 2, 3]
    }

    A note about JsonEvents in spac: JSON doesn't have any explicit markers for when a field ends, or when an array index starts or ends; those context changes are essentially inferred by the presence of some other event. For example, instead of a "field end" event, typically there will be either a new "field start" or a token representing the end of the current object. With spac, splitters and context matchers generally operate under the assumption that a "stack push" event (like a field start) will eventually be followed by a corresponding "stack pop" event (i.e. field end).

    To allow for this, these "inferred" events (FieldEnd, IndexStart, IndexEnd) are explicitly represented as JsonEvents in the stream being parsed. Keep this in mind when creating JSON ContextMatchers:

    • field-related matchers will match a stack like case ObjectStart :: FieldStart(_) :: _
    • index-related matchers will match a stack like case ArrayStart :: IndexStart(_) :: _
    Definition Classes
    spac
  • package xml

    This package provides extensions to the core "spac" library which allow for the handling of XML data.

    This package provides extensions to the core "spac" library which allow for the handling of XML data.

    Rather than creating explicit classes that extend Parser, Transformer, and Splitter, this package provides type aliases and implicit extensions. For example, XmlParser[A] is just a type alias for Parser[XmlEvent, A], and XmlParser is just a call to Parser[XmlEvent].

    Three main Parser methods are added to Parser[XmlEvent] via the XmlParserApplyOps implicit class:

    • XmlParser.forText - for capturing raw text
    • XmlParser.attr - for capturing mandatory attributes from elements
    • XmlParser.attrOpt - for capturing optional attributes from elements

    One main Splitter constructor method is added to Splitter via the XmlSplitterApplyOps implicit class:

    • Splitter.xml - for creating splitters based on an inspection of an "element stack"

    Three main Splitter member methods are added to Splitter[XmlEvent, C] via the XmlSplitterOps implicit class:

    • .attr - alias for .joinBy(XmlParser.attr(...))
    • .attrOpt - alias for .joinBy(XmlParser.attrOpt(...))
    • .text - alias for .joinBy(XmlParser.forText)

    A DSL for creating xml-specific ContextMatchers is provided to make it more convenient to call Splitter.xml. For example:

    Splitter.xml("things" \ "thing").attr("foo").parseToList

    Can be used to capture a list of the "foo" attributes in the <thing> elements in

    <things>
       <thing foo="hello" />
       <thing foo="Goodbye">
          <extra>junk</extra>
       </thing>
    </thing>
    Definition Classes
    spac
  • CallerPos
  • ContextChange
  • ContextLocation
  • ContextMatcher
  • ContextPop
  • ContextPush
  • ContextTrace
  • HasLocation
  • LowPriorityTypeReduceImplicits
  • Parser
  • ParserApplyWithBoundInput
  • Signal
  • SingleItemContextMatcher
  • Source
  • SpacException
  • SpacTraceElement
  • Splitter
  • SplitterApplyWithBoundInput
  • StackInterpretation
  • StackLike
  • Transformer
  • TransformerApplyWithBoundInput
  • TypeReduce
  • Unconsable

object ContextMatcher

Source
ContextMatcher.scala
Linear Supertypes
AnyRef, Any
Ordering
  1. Alphabetic
  2. By Inheritance
Inherited
  1. ContextMatcher
  2. AnyRef
  3. Any
  1. Hide All
  2. Show All
Visibility
  1. Public
  2. Protected

Type Members

  1. case class Chained[Elem, H, T, F](headM: ContextMatcher[Elem, H], tailM: ContextMatcher[Elem, T])(implicit reduce: Aux[H, T, F]) extends ContextMatcher[Elem, F] with Product with Serializable

    Matcher implementation for headM \ tailM

    Matcher implementation for headM \ tailM

    H

    The head result type

    T

    The tail result type

    F

    The combined result type

    headM

    The first matcher in the chain

    tailM

    The next matcher in the chain

    reduce

    The TypeReduce rule to combine the head and tail result types

  2. case class Mapped[Elem, A, B](inner: ContextMatcher[Elem, A], op: String = "map")(f: (A) => Option[B]) extends ContextMatcher[Elem, B] with Product with Serializable

    Matcher implementation for the map, flatMap, and filter operations.

    Matcher implementation for the map, flatMap, and filter operations.

    A

    The type of the matched context.

    B

    The transformed context type

    inner

    The transformed mapper

    op

    The name of the operation, used by toString

    f

    The transform operation

  3. case class Or[Elem, A](left: ContextMatcher[Elem, A], right: ContextMatcher[Elem, A]) extends ContextMatcher[Elem, A] with Product with Serializable

    Matcher implementation for left | right.

    Matcher implementation for left | right.

    A

    The type of the matched context.

    left

    The left matcher (i.e. the first choice)

    right

    The right matcher (i.e. the fallback)

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(classOf[java.lang.CloneNotSupportedException]) @native()
  6. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  7. def equals(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef → Any
  8. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.Throwable])
  9. final def getClass(): Class[_ <: AnyRef]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  10. def greedy[Elem, A](f: (IndexedSeq[Elem], Int, Int) => Option[(A, Int)]): ContextMatcher[Elem, A]

    A matcher that uses a custom function f to consume the first N elements from the input before passing the remainder to the next matcher in the chain.

    A matcher that uses a custom function f to consume the first N elements from the input before passing the remainder to the next matcher in the chain.

    For example:

    Matcher.greedy { (stack, offset, avail) =>
      if(avail >= 2 && stack(offset) == "foo" && stack(offset + 1) == "bar"){
        Some("yes!" -> 2)
      } else {
        None
      }
    }
    A

    The matcher function's result type

    f

    The matching function. Given a reference to the stack elements, an offset position, and the number of elements available starting from the offset, f should return an option containing a pair of the matched value and the unconsumed portion of the stack.

    returns

    A new matcher which uses f to determine how (and how much of) the stack is matched

  11. def hashCode(): Int
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  12. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  13. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  14. def noopFailure[Elem]: ContextMatcher[Elem, Unit]

    A matcher that quickly rejects any input

  15. def noopSuccess[Elem]: ContextMatcher[Elem, Unit]

    A matcher that quickly matches any input as () without consuming any stack.

  16. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  17. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  18. final def synchronized[T0](arg0: => T0): T0
    Definition Classes
    AnyRef
  19. def toString(): String
    Definition Classes
    AnyRef → Any
  20. def variableLength[Elem]: ContextMatcher[Elem, Unit]

    A matcher that matches any input as long as the next matcher in the chain will match some segment of that input.

  21. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  22. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  23. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException]) @native()

Inherited from AnyRef

Inherited from Any

Ungrouped