eu.bandm.tools.ramus.runtime2

Class Action<R,M,O>

java.lang.Object

eu.bandm.tools.ramus.runtime2.Action<R,M,O>

Type Parameters:

R - the type of parsing results attached to leaves

M - the type of diagnostic messages attached to stems

O - the type of obstructions to continuation

Direct Known Subclasses:

Blockage, Choice, Diagnosis, Success

public abstract class Action<R,M,O>
extends Object

Base class of the parsing search-tree monad.

Search trees must not share nodes internally or externally. Some operations on search trees are transitions that may induce sharing between the input and output tree. If such a method is invoked and the output is used, then the input may not be used simultaneously anymore.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	Action.BiContinuation<R,S,T,M,O> Functional interface for binary continuations.
static interface	Action.Continuation<R,S,M,O> Functional interface for continuations.
static class	Action.Trampoline<R,S,M,O>
static class	Action.Visitor<R,M,O>

Constructor Summary

Constructors

Constructor and Description
Action()

Method Summary

Modifier and Type	Method and Description
abstract <S> Action<S,M,O>	bind(Action.Continuation<? super R,S,M,O> cont) Applies a monadic continuation to all leaves of this search tree (transition operation).
static <R,M,O> Action<R,M,O>	choice(Action<R,M,O>... alts) Creates a search tree from a choice of alternative subtrees
static <R,M,O> Action<R,M,O>	diagnosis(Action<R,M,O> body, List<? extends M> msgs) Creates a search tree with diagnostic message attached to the root.
static <R,M,O> Action<R,M,O>	diagnosis(Action<R,M,O> body, M... msgs) Creates a search tree with diagnostic message attached to the root.
static <R,M,O> Action<R,M,O>	fail() Creates a search tree with no alternatives.
static <R,M,O> Action<R,M,O>	fail(O obstruction) Creates a search tree with no alternatives but an obstruction.
static <R,M,O> Action.Visitor<R,M,O>	forEachObstruction(BiConsumer<O,ReverseList<M>> op)
static <R,M,O> Action.Visitor<R,M,O>	forEachResult(BiConsumer<R,ReverseList<M>> op)
protected abstract int	getLeafCount()
abstract void	host(Action.Visitor<? super R,M,O> v) Performs a double dispatch to the appropriate method of a visitor.
abstract boolean	isEmpty() Checks whether this search tree is empty.
<S> Action<S,M,O>	map(Function<? super R,? extends S> fun) Applies a function to all leaves of this search tree (transition operation).
static <R,M,O> Action<R,M,O>	optional(Optional<? extends R> opt)
static <R,S,M,O> Action<R,M,O>	optional(Optional<S> opt, Function<? super S,? extends R> convert)
abstract <Q> Action<? extends R,M,Q>	prune() Simplifies this search tree by removing redundant choice nodes and all obstructions (transition operation).
protected <Q> boolean	pruneTo(List<? super Action<? extends R,M,Q>> alts) Adds a pruned variant of this search subtree to a list of choice alternatives.
static <R,M,O> Action<R,M,O>	succeed(R result) Creates a search tree with a single leaf.
static <R,M,O> Action<R,M,O>	succeed(R result, Success<?,M,O> recyclable) Creates a search tree with a single leaf, possibly using a recyclable leaf node.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Action

public Action()

Method Detail

getLeafCount

protected abstract int getLeafCount()

bind

public abstract <S> Action<S,M,O> bind(Action.Continuation<? super R,S,M,O> cont)

Applies a monadic continuation to all leaves of this search tree (transition operation).

Type Parameters:

S - the output parsing result type of the continuation

Parameters:

cont - the continuation to apply

Returns:

an updated search tree

map

public final <S> Action<S,M,O> map(Function<? super R,? extends S> fun)

Applies a function to all leaves of this search tree (transition operation).

Type Parameters:

S - the output parsing result type of the continuation

Parameters:

fun - the function to apply

Returns:

an updated search tree

isEmpty

public abstract boolean isEmpty()

Checks whether this search tree is empty.

Returns:

true iff this tree has no leaves

prune

public abstract <Q> Action<? extends R,M,Q> prune()

Simplifies this search tree by removing redundant choice nodes and all obstructions (transition operation).

Type Parameters:

Q - the new type of obstructions

Returns:

a simplified search tree without nested or unary choice nodes

pruneTo

protected <Q> boolean pruneTo(List<? super Action<? extends R,M,Q>> alts)

Adds a pruned variant of this search subtree to a list of choice alternatives.

Type Parameters:

Q - the new type of obstructions

Parameters:

alts - the list to add to

Returns:

true iff this subtree has been simplified by recursive pruning

fail

public static <R,M,O> Action<R,M,O> fail()

Creates a search tree with no alternatives.

Type Parameters:

R - the type of parsing results attached to leaves

M - the type of diagnostic messages attached to stems

O - the type of obstructions to continuation

Returns:

a search tree with no alternatives

fail

public static <R,M,O> Action<R,M,O> fail(O obstruction)

Creates a search tree with no alternatives but an obstruction.

Type Parameters:

R - the type of parsing results attached to leaves

M - the type of diagnostic messages attached to stems

O - the type of obstructions to continuation

Parameters:

obstruction - the obstruction to fail with

Returns:

a search tree with no alternatives

succeed

public static <R,M,O> Action<R,M,O> succeed(R result)

Creates a search tree with a single leaf.

Type Parameters:

R - the type of parsing results attached to leaves

M - the type of diagnostic messages attached to stems

O - the type of obstructions to continuation

Parameters:

result - the parsing result

Returns:

a tree with a single leaf holding the given result

succeed

public static <R,M,O> Action<R,M,O> succeed(R result,
                                            Success<?,M,O> recyclable)

Creates a search tree with a single leaf, possibly using a recyclable leaf node.

Type Parameters:

R - the type of parsing results attached to leaves

M - the type of diagnostic messages attached to stems

O - the type of obstructions to continuation

Parameters:

result - the parsing result

recyclable - a recyclable leaf node, or null if not available

Returns:

a leaf node with a newly computed parsing result; either recyclable if available or new.

diagnosis

@SafeVarargs
public static <R,M,O> Action<R,M,O> diagnosis(Action<R,M,O> body,
                                                           M... msgs)

Creates a search tree with diagnostic message attached to the root.

Type Parameters:

R - the type of parsing results attached to leaves

M - the type of diagnostic messages attached to stems

O - the type of obstructions to continuation

Parameters:

body - the search tree to attach messages to

msgs - an array of messages to attach

Returns:

a search tree with the messages attached to the body

Throws:

IllegalArgumentException - if body == null or msgs == null

diagnosis

public static <R,M,O> Action<R,M,O> diagnosis(Action<R,M,O> body,
                                              List<? extends M> msgs)

Creates a search tree with diagnostic message attached to the root.

Type Parameters:

R - the type of parsing results attached to leaves

M - the type of diagnostic messages attached to stems

O - the type of obstructions to continuation

Parameters:

body - the search tree to attach messages to

msgs - a list of messages to attach

Returns:

a search tree with the messages attached to the body

Throws:

IllegalArgumentException - if body == null or msgs == null

choice

@SafeVarargs
public static <R,M,O> Action<R,M,O> choice(Action<R,M,O>... alts)

Creates a search tree from a choice of alternative subtrees

Type Parameters:

R - the type of parsing results attached to leaves

M - the type of diagnostic messages attached to stems

O - the type of obstructions to continuation

Parameters:

alts - an array of alternative subtrees

Returns:

a search tree with a choice root and the given alternatives

Throws:

IllegalArgumentException - if alts == null

optional

public static <R,M,O> Action<R,M,O> optional(Optional<? extends R> opt)

optional

public static <R,S,M,O> Action<R,M,O> optional(Optional<S> opt,
                                               Function<? super S,? extends R> convert)

host

public abstract void host(Action.Visitor<? super R,M,O> v)

Performs a double dispatch to the appropriate method of a visitor.

Parameters:

v - the visitor

forEachResult

public static <R,M,O> Action.Visitor<R,M,O> forEachResult(BiConsumer<R,ReverseList<M>> op)

forEachObstruction

public static <R,M,O> Action.Visitor<R,M,O> forEachObstruction(BiConsumer<O,ReverseList<M>> op)