dk.brics.string.flow.operations
Class Simplifier

java.lang.Object
  dk.brics.string.flow.operations.Simplifier

public class Simplifier
extends Object

Flow graph simplifier.

Method Summary

static void	normalize(FlowGraph g) Normalizes the given graph.
static Map<Node,Node>	simplify(FlowGraph g) Simplifies the given graph.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

normalize

public static void normalize(FlowGraph g)

Normalizes the given graph. In a normalized graph, only assignment nodes may have multiple incoming edges. (Concat nodes and binary operation nodes have at most one edge for each argument.)

simplify

public static Map<Node,Node> simplify(FlowGraph g)

Simplifies the given graph. Performs the following optimizations:

• Nodes that are of same type and have ingoing edges from the same nodes are merged.
• Sequences of assignments with only one ingoing edge are compressed.
• Concatenation nodes are bypassed if the first argument has exactly one edge and it comes from an initialization node with the empty string.
• Self-loops on assignments are removed.

Returns:

a map from the original nodes to the corresponding node in the simplified graph