Rules ( Rule )

Definition

An instance r of the data type Rule is a rule p₁ $\wedge$...$\wedge$ p_k $\rightarrow$ q, where p₁,...p_k, q are properties (of type AgdKey). The interpretation of such a rule is, that property q holds if all properties p₁,..., p_k are satisfied, e.g., forest $\wedge$ singlesource $\rightarrow$ tree means that a graph which represents a forest with a single source is a tree.

If a rule is stored in a rule administrator admin, it is assigned a unique index, which, e.g., can be used for realizing arrays indexed by rules in admin.

We use the following abbreviations: p $\rightarrow$ q₁ $\wedge$...$\wedge$ q_k stands for the k rules p $\rightarrow$ q₁,..., p $\rightarrow$ q_k, and q $\leftrightarrow$ p₁ $\wedge$...$\wedge$ p_k stands for the k + 1 rules p₁ $\wedge$...$\wedge$ p_k $\rightarrow$ q and q $\rightarrow$ p₁,..., q $\rightarrow$ p_k.

#include < AGD/Rule.h >

Creation

Rule	r	creates an instances r of type Rule initialized to $\rightarrow$ nil.
Rule	r(AgdKey q)	creates an instances r of type Rule initialized to $\rightarrow$ q.
Rule	r(AgdKey p1, AgdKey q)	creates an instances r of type Rule initialized to p1 $\rightarrow$ q.
Rule	r(AgdKey p1, AgdKey p2, AgdKey q)
		creates an instances r of type Rule initialized to p1 $\wedge$ p2 $\rightarrow$ q.
Rule	r(AgdKey p1, AgdKey p2, AgdKey p3, AgdKey q)
		creates an instances r of type Rule initialized to p1 $\wedge$ p2 $\wedge$ p3 $\rightarrow$ q.
Rule	r(const Rule& r)	creates an instances r of type Rule identical to r.

Operations

const leda_list<AgdKey>&	r.left()	returns the left side of r, i.e., p1 $\wedge$...$\wedge$ pk.
AgdKey	r.right()	returns the right side of r, i.e., q.
int	r.length()	returns the number k of properties on the left side of r.
int	r.index()	returns the index of r.
Rule&	r.And(AgdKey p)	extends r to p1 $\wedge$...$\wedge$ pk $\wedge$ p $\rightarrow$ q and returns r.
Rule&	r.implies(AgdKey q)	sets the right side of r to q and returns r.
Rule&	r.index(int id)	sets the index of r to id and returns r.
ostream&	ostream& os << const Rule& r
		writes rule r to output stream os.