Package com.singularsys.extensions.rewrite

Allow expression rewriting to be created and applied. Rules must implement RewriteRuleI providing methods boolean test(ASTFunNode node,Node children[]) and Node apply(ASTFunNode node,Node children[]). The set of rewriting rules can be applied using the RewriteVisitor.

For example

Jep jep = new Jep();
jep.setComponent(new DeepCopyVisitor());
jep.setComponent(new TreeUtils());
jep.setComponent(new SimplificationVisitor());
RewriteVisitor ev = new RewriteVisitor();
jep.setComponent(ev);
RewriteRuleI expand = new ExpandBrackets();
ev.add(expand);                 // Add the rule
jep.reinitializeComponents();   // reinitialize Jep
    
Node node = jep.parse("(a+b)*(c+d)");
Node expanded = ev.rewrite(node,false); // perform the rewriting
jep.println(expanded);

Since:

Jep 3.5 / Extensions 2.0

See Also:

Rewrite documentation

Interface Summary

Interface	Description
RewriteRuleI	Defines a rule for symbolic rewriting of an expression
RewriteVisitor.ConstantRuleI
RewriteVisitor.VariableRuleI	Define a rule which may modify a variable node.

Class Summary

Class	Description
AbstractRewrite	Basic implementation for a RewriteRule.
CollectPowers	Collect powers together so that x*x -> x^2 and x^n*x -> x^(n+1).
ExpandBrackets	A rule which expands brackets (a+b)*(c+d) -> a*c+a*d+b*c+b*d
ExpandPower	Expands powers (a+b)^2 -> a^2+2*a*b+b^2
RewriteVisitor	A visitor which allows rewrite rules to be added and applied.
SmallNumberRule	A rule where numbers very close to zero are replaces by zero.
VariableShifter	Replaces a variable "x" by "x + d" where d is a double value.