pulsatrix::datalog::Term Class Reference

A Datalog term: either a constant (e.g. a) or a variable (e.g. X) – never a compound/function-symbol term. More...

#include <datalog_term.hpp>

Public Member Functions
TermKind	kind () const
	Whether this term is a constant or a variable.
bool	is_constant () const
	True iff this term is a constant.
bool	is_variable () const
	True iff this term is a variable.
const std::string &	value () const
	The constant's value, or the variable's name – whichever this term is.
bool	operator== (const Term &other) const
bool	operator!= (const Term &other) const

Static Public Member Functions
static Term	make_constant (std::string value)
	Constructs a constant term with the given value (e.g. "a").
static Term	make_variable (std::string name)
	Constructs a variable term with the given name (e.g. "X").

Detailed Description

A Datalog term: either a constant (e.g. a) or a variable (e.g. X) – never a compound/function-symbol term.

Note

Enforced structurally, not just documented: the only state this class stores is a TermKind tag plus a single std::string payload (the constant's value or the variable's name). There is no member, constructor, or accessor through which a Term could ever hold another Term or a list of Terms – the decidable-fragment restriction (campaign doc Risk Register: "no function symbols, no unbounded recursion over complex/nested terms") is a property of this type's shape, not a runtime check that could be bypassed.

Representation choice (mission Stage 3 design question 2): interned as plain std::strings, compared/hashed via std::string's own operator==/std::hash, not small integer IDs. Rationale: this mission's stated scope is the boolean semiring on toy-scale knowledge bases (campaign Risk Register: "keep Phase 3's exit-gate knowledge base deliberately small ... until proven") – correctness and readability of hand-verified fixpoint traces matter far more than string-comparison performance at this stage. An integer-interning table is a legitimate future optimization if Mission 1/2's real-valued semiring work hits an actual bottleneck, but building it now would be optimizing ahead of a need this mission doesn't have.

Member Function Documentation

is_constant()

bool pulsatrix::datalog::Term::is_constant ( ) const

inline

True iff this term is a constant.

is_variable()

bool pulsatrix::datalog::Term::is_variable ( ) const

inline

True iff this term is a variable.

kind()

TermKind pulsatrix::datalog::Term::kind ( ) const

inline

Whether this term is a constant or a variable.

make_constant()

static Term pulsatrix::datalog::Term::make_constant ( std::string  value )

inlinestatic

Constructs a constant term with the given value (e.g. "a").

make_variable()

static Term pulsatrix::datalog::Term::make_variable ( std::string  name )

inlinestatic

Constructs a variable term with the given name (e.g. "X").

operator!=()

bool pulsatrix::datalog::Term::operator!= ( const Term &  other ) const

inline

operator==()

bool pulsatrix::datalog::Term::operator== ( const Term &  other ) const

inline

value()

const std::string & pulsatrix::datalog::Term::value ( ) const

inline

The constant's value, or the variable's name – whichever this term is.

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The documentation for this class was generated from the following file:

• include/pulsatrix/datalog_term.hpp