Package com.singularsys.jep.walkers

Expression tree traversal classes.

See:
Description

Interface Summary

SerializableExpression.Element

interface used in internal representation of expression

Class Summary

DeepCopyVisitor	A Visitor which returns an exact copy of the tree.
DoNothingVisitor	A Visitor which visits each node of a expression tree and does nothing.
PostfixEvaluator	Evaluation component that avoids excessive use of the stack for large expressions.
PostfixTreeWalker	Base class for routines which use a non recursive tree walker strategy.
PrefixTreeDumper	Dumps the contents of a tree to a specified stream, or to standard output.
PrefixTreeWalker	Base class for routines which use a non recursive tree walker strategy.
SerializableExpression	A serializable representation of an expression.
SerializableExpression.Constant
SerializableExpression.Function
SerializableExpression.Operator
SerializableExpression.Variable
SubstitutionVisitor	Allows substitution of a given variable with an expression tree.
TreeAnalyzer	Analyze an expression, counting the number of nodes of each type, and recording which variables, functions and operators occurred in the expression.

Package com.singularsys.jep.walkers Description

Expression tree traversal classes.

These classes implement various methods of transversing trees representing equations. For very large equations with 10,000+ nodes the standard ParserVisitor class can encounter problems with stack overflows due to recursions. The PostfixTreeWalker offers a base class for a transversal strategy which minimises the number of stack frames used and the PostfixEvaluator is an evaluator which uses this strategy. These methods visit each node in postfix fashion hence for 1+cos(x) the nodes are visited in the order 1, x, cos, +.

PrefixTreeWalker is similar but visits nodes in a prefix fashion for 1+cos(x) the nodes are visited in the order +, 1, cos, x.

DoNothingVisitor and DeepCopyVisitor are two base classes for classes which manipulate expressions using a standard recursive transversal. DoNothingVisitor visits each node in turn performing no action and returning the node. DeepCopyVisitor visits each node returning a copy of that node.