libsemigroups
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Template class for transformations. More...
#include <elements.h>
Public Member Functions | |
Element * | really_copy (size_t increase_deg_by=0) const override |
Returns a pointer to a copy of this . More... | |
void | redefine (Element const *x, Element const *y) override |
Multiply x and y and stores the result in this . More... | |
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size_t | complexity () const override |
Returns the approximate time complexity of multiplying two partial transformations. More... | |
size_t | crank () const |
Returns the rank of a partial transformation. More... | |
size_t | degree () const override |
Returns the degree of a partial transformation. More... | |
Element * | identity () const override |
Returns the identity transformation with degrees of this . More... | |
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ElementWithVectorData () | |
A constructor. More... | |
ElementWithVectorData (std::vector< T > *vector) | |
A constructor. More... | |
ElementWithVectorData (std::vector< T > const &vector) | |
A constructor. More... | |
T | at (size_t pos) const |
Returns the pos entry in the vector containing the defining data. More... | |
std::vector< T >::iterator | begin () const |
Returns an iterator. More... | |
std::vector< T >::iterator | cbegin () const |
Returns a const iterator. More... | |
std::vector< T >::iterator | cend () const |
Returns a const iterator. More... | |
void | copy (Element const *x) override |
Copy another Element into this . More... | |
std::vector< T >::iterator | end () const |
Returns an iterator. More... | |
bool | operator< (Element const &that) const override |
Returns true if this is less than that . More... | |
bool | operator== (Element const &that) const override |
Returns true if this equals that . More... | |
T | operator[] (size_t pos) const |
Returns the pos entry in the vector containing the defining data. More... | |
Element * | really_copy (size_t increase_deg_by=0) const override |
Returns a pointer to a copy of this . More... | |
void | really_delete () override |
Deletes the defining data of an ElementWithVectorData. More... | |
void | swap (Element *x) override |
Swap another Element with this . More... | |
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Element (elm_t type=Element::elm_t::NOT_RWSE) | |
A constructor. More... | |
virtual | ~Element () |
A default destructor. More... | |
elm_t | get_type () const |
Returns the type libsemigroups::Element::elm_t of an Element object. More... | |
size_t | hash_value () const |
Return the hash value of an Element. More... | |
virtual void | redefine (Element const *x, Element const *y, size_t const &thread_id) |
Multiplies x and y and stores the result in this . More... | |
Protected Member Functions | |
void | cache_hash_value () const override |
This method is included because it seems to give superior performance in some benchmarks. More... | |
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void | cache_hash_value () const override |
This method implements the default hash function for an ElementWithVectorData, which uses ElementWithVectorData::vector_hash. Derive from this class if you are defining a class derived from ElementWithVectorData and there is a specialization of std::hash for the template parameter TValueType , and you do not want to define a hash function explicitly in your derived class. More... | |
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void | reset_hash_value () const |
Reset the cached value used by Element::hash_value. More... | |
Additional Inherited Members | |
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enum | elm_t { RWSE = 0, NOT_RWSE = 1 } |
This enum contains some different types of Element. More... | |
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static T const | UNDEFINED |
Undefined image value. More... | |
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static size_t | vector_hash (std::vector< T > const *vec) |
Returns a hash value for a vector provided there is a specialization of std::hash for the template type T . More... | |
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std::vector< T > * | _vector |
The vector containing the defining data of this . More... | |
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static size_t const | UNDEFINED = std::numeric_limits<size_t>::max() |
UNDEFINED value. More... | |
Template class for transformations.
The value of the template parameter T
can be used to reduce the amount of memory required by instances of this class; see PartialTransformation and ElementWithVectorData for more details.
A transformation \(f\) is just a function defined on the whole of \(\{0, 1, \ldots, n - 1\}\) for some integer \(n\) called the degree of \(f\). A transformation is stored as a vector of the images of \(\{0, 1, \ldots, n - 1\}\), i.e. \(\{(0)f, (1)f, \ldots, (n - 1)f\}\).
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inlineoverrideprotectedvirtual |
This method is included because it seems to give superior performance in some benchmarks.
Implements libsemigroups::Element.
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inlineoverridevirtual |
Returns a pointer to a copy of this
.
See Element::really_copy for more details about this method.
The copy returned by this method fixes all the values between the Transformation::degree of this
and increase_deg_by
.
Implements libsemigroups::Element.
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inlineoverridevirtual |
Multiply x
and y
and stores the result in this
.
See Element::redefine for more details about this method.
This method asserts that the degrees of x
, y
, and this
, are all equal, and that neither x
nor y
equals this
.
Reimplemented from libsemigroups::Element.