class Automaton

Declaration

template <typename ActionT>
class Automaton { /* full declaration omitted */ };

Description

A deterministic finite-state automaton. The automaton is defined in TableGen; this object drives an automaton defined by tblgen-emitted tables. An automaton accepts a sequence of input tokens ("actions"). This class is templated on the type of these actions.

Declared at: llvm/include/llvm/Support/Automaton.h:162

Templates

ActionT

Method Overview

• public Automaton<ActionT>(const Automaton<ActionT> & Other)
• public template <typename InfoT> Automaton<ActionT>(ArrayRef<InfoT> Transitions, ArrayRef<llvm::NfaStatePair> TranscriptionTable = {})
• public bool add(const ActionT & A)
• public bool canAdd(const ActionT & A)
• public void enableTranscription(bool Enable = true)
• public ArrayRef<llvm::NfaPath> getNfaPaths()
• public void reset()

Methods

¶Automaton<ActionT>(
    const Automaton<ActionT>& Other)

Declared at: llvm/include/llvm/Support/Automaton.h:205

Parameters

const Automaton<ActionT>& Other

¶template <typename InfoT>
Automaton<ActionT>(ArrayRef<InfoT> Transitions,
                   ArrayRef<llvm::NfaStatePair>
                       TranscriptionTable = {})

Description

Create an automaton. Providing the TranscriptionTable argument as non-empty will enable the use of transcription, which analyzes the possible paths in the original NFA taken by the DFA. NOTE: This is substantially more work than simply driving the DFA, so unless you require the getPaths() method leave this empty.

Declared at: llvm/include/llvm/Support/Automaton.h:193

Templates

InfoT

Parameters

ArrayRef<InfoT> Transitions

The Transitions table as created by TableGen. Note that because the action type differs per automaton, the table type is templated as ArrayRef <InfoT >.

ArrayRef<llvm::NfaStatePair> TranscriptionTable = {}

The TransitionInfo table as created by TableGen.

¶bool add(const ActionT& A)

Description

Transition the automaton based on input symbol A. Return true if the automaton transitioned to a valid state, false if the automaton transitioned to an invalid state. If this function returns false, all methods are undefined until reset() is called.

Declared at: llvm/include/llvm/Support/Automaton.h:235

Parameters

const ActionT& A

¶bool canAdd(const ActionT& A)

Description

Return true if the automaton can be transitioned based on input symbol A.

Declared at: llvm/include/llvm/Support/Automaton.h:246

Parameters

const ActionT& A

¶void enableTranscription(bool Enable = true)

Description

Enable or disable transcription. Transcription is only available if TranscriptionTable was provided to the constructor.

Declared at: llvm/include/llvm/Support/Automaton.h:222

Parameters

bool Enable = true

¶ArrayRef<llvm::NfaPath> getNfaPaths()

Description

Obtain a set of possible paths through the input nondeterministic automaton that could be obtained from the sequence of input actions presented to this deterministic automaton.

Declared at: llvm/include/llvm/Support/Automaton.h:254

¶void reset()

Description

Reset the automaton to its initial state.

Declared at: llvm/include/llvm/Support/Automaton.h:214