hfst Namespace Reference

A namespace for HFST functions and datatypes. More...

Namespaces
	implementations
	A namespace for all code that forms a bridge between backend libraries and HFST.
	rules
	A namespace for functions that create two-level, replace, restriction and coercion rule transducers.
	xeroxRules
	A namespace for HFST xeroxRules functions and data types.

Classes
class	HfstInputStream
	A stream for reading HFST binary transducers. More...
class	HfstOutputStream
	A stream for writing binary transducers. More...
class	HfstTokenizer
	A tokenizer for creating transducers from UTF-8 strings. More...
class	HfstTransducer
	A synchronous finite-state transducer. More...

Typedefs
typedef std::pair< float, StringVector >	HfstOneLevelPath
	A path of one level of arcs with collected weight. More...
typedef std::set < HfstOneLevelPath >	HfstOneLevelPaths
	A set of simple paths. More...
typedef std::map< StringPair, StringPair >	HfstSymbolPairSubstitutions
	A map of substitutions used when performing multiple symbol pair-to-symbol pair substitutions. More...
typedef std::map< String, String >	HfstSymbolSubstitutions
	A map of substitutions used when performing multiple symbol-to-symbol substitutions. More...
typedef std::pair < HfstTransducer, HfstTransducer >	HfstTransducerPair
	A pair of transducers. More...
typedef std::vector < HfstTransducerPair >	HfstTransducerPairVector
	A vector of transducer pairs. More...
typedef std::vector < HfstTransducer >	HfstTransducerVector
	a vector of transducers for methods applying a cascade of automata More...
typedef std::pair< float, StringPairVector >	HfstTwoLevelPath
	A path of two level of arcs with collected weight. More...
typedef std::set < HfstTwoLevelPath >	HfstTwoLevelPaths
	A set of two-level weighted paths. More...
typedef std::string	String
	A UTF-8 symbol in a transition. More...
typedef std::pair< String, String >	StringPair
	A symbol pair in a transition. More...
typedef std::set< StringPair >	StringPairSet
	A set of symbol pairs used in substituting symbol pairs and in rule functions. More...
typedef std::vector< std::pair < std::string, std::string > >	StringPairVector
	A vector of string pairs. More...
typedef std::vector< std::string >	StringVector
	A vector of strings. More...

Enumerations
enum	ImplementationType {   SFST_TYPE,   TROPICAL_OPENFST_TYPE,   LOG_OPENFST_TYPE,   FOMA_TYPE,   XFSM_TYPE,   HFST_OL_TYPE,   HFST_OLW_TYPE,   HFST2_TYPE,   UNSPECIFIED_TYPE,   ERROR_TYPE }
	The type of an HfstTransducer. More...
enum	PushType {   TO_INITIAL_STATE,   TO_FINAL_STATE }
	The type of a push operation. More...

Functions
std::ostream &	operator<< (std::ostream &out, const HfstTransducer &t)
	Write transducer t in AT&T format to ostream out. More...

Detailed Description

A namespace for HFST functions and datatypes.

Typedef Documentation

typedef std::pair< float, StringVector > HfstOneLevelPath

A path of one level of arcs with collected weight.

Used as the source and result data type for lookups and downs. In the first case, the float is ignored. In the latter case, the float represents the weight of the path.

See also

HfstTokenizer::lookup_tokenize

HfstTransducer::lookup

typedef std::set<HfstOneLevelPath> HfstOneLevelPaths

A set of simple paths.

Used as return type of lookup with multiple, unique results.

typedef std::map<StringPair, StringPair> HfstSymbolPairSubstitutions

A map of substitutions used when performing multiple symbol pair-to-symbol pair substitutions.

See also

HfstTransducer::substitute(const HfstSymbolPairSubstitutions&)

typedef std::map<String, String> HfstSymbolSubstitutions

A map of substitutions used when performing multiple symbol-to-symbol substitutions.

See also

HfstTransducer::substitute(const HfstSymbolSubstitutions&)

typedef std::pair<HfstTransducer,HfstTransducer> HfstTransducerPair

A pair of transducers.

Used by functions in namespace rules

typedef std::vector<HfstTransducerPair> HfstTransducerPairVector

A vector of transducer pairs.

Used by functions in namespace rules

typedef std::vector< HfstTransducer > HfstTransducerVector

a vector of transducers for methods applying a cascade of automata

A vector of transducers.

Used by compose_intersect.

typedef std::pair< float, StringPairVector > HfstTwoLevelPath

A path of two level of arcs with collected weight.

typedef std::set< HfstTwoLevelPath > HfstTwoLevelPaths

A set of two-level weighted paths.

typedef std::string String

A UTF-8 symbol in a transition.

Strings "@_EPSILON_SYMBOL_@", "@_UNKNOWN_SYMBOL_@" and "@_IDENTITY_SYMBOL_@" are reserved.

• "@_EPSILON_SYMBOL_@" denotes the epsilon (in AT&T formalism [0]).
• "@_UNKNOWN_SYMBOL_@" denotes an unknown symbol, i.e. any symbol that does not occur or has not occurred in the transducer (in AT&T formalism [?], [?:x], [x:?]).

• "@_IDENTITY_SYMBOL_@" denotes any unknown symbol that is the same on the input and output side of a transition (in AT&T formalism [?:?]).

  For an example of special symbols, see HFST transducer documentation.

Strings of form @[PNDRCU][.][A-Z]+([.][A-Z]+)?@ are reserved for flag diacritics. For an example of flag diacritics, see hfst::HfstTransducer::extract_paths_fd(hfst::HfstTwoLevelPaths&, int, int, bool) const. For more information on flag diacritics, see Finite State Morphology (Beesley & Karttunen, 2003).

typedef std::pair<String, String> StringPair

A symbol pair in a transition.

See also

HfstTransducer::substitute(const StringPair&, const StringPair&) and other substitute functions

typedef std::set<StringPair> StringPairSet

A set of symbol pairs used in substituting symbol pairs and in rule functions.

See also

HfstTransducer::substitute(const StringPair&, const StringPairSet &) hfst::rules

typedef std::vector< StringPair > StringPairVector

A vector of string pairs.

A vector of transitions that represents a path in a transducer.

Used by typedef HfstTwoLevelPath.

See also

HfstTokenizer

typedef std::vector< std::string > StringVector

A vector of strings.

Used by typedef HfstOneLevelPath.

Enumeration Type Documentation

enum ImplementationType

The type of an HfstTransducer.

Enumerator
SFST_TYPE	An SFST transducer, unweighted.
TROPICAL_OPENFST_TYPE	An OpenFst transducer with tropical weights.
LOG_OPENFST_TYPE	An OpenFst transducer with logarithmic weights.
FOMA_TYPE	A foma transducer, unweighted.
XFSM_TYPE	An xfsm transducer, unweighted (mostly for testing purposes).
HFST_OL_TYPE	An HFST optimized lookup transducer, unweighted
HFST_OLW_TYPE	An HFST optimized lookup transducer with weights
HFST2_TYPE	HFST2 header present, conversion required
UNSPECIFIED_TYPE	Format left open by e.g. default constructor
ERROR_TYPE	Type not recognised. This type might be returned by a function if an error occurs.

enum PushType

The type of a push operation.

See also

HfstTransducer::push_weights

Enumerator
TO_INITIAL_STATE	Push weights towards initial state.
TO_FINAL_STATE	Push weights towards final state(s).

Function Documentation

HFSTDLL std::ostream & operator<<	(	std::ostream &	out,
		const HfstTransducer &	t
	)

Write transducer t in AT&T format to ostream out.

The same as hfst::HfstTransducer::write_in_att_format(FILE*, bool) const with ostreams. Weights are written if the type of t is weighted.