com.goldencode.p2j.pattern

Interface PatternWorker

All Known Implementing Classes:

AbstractConversionWorker, AbstractPatternWorker, BufferScopeWorker, CallGraphWorker, CommonAstSupport, ConverterHelper, DatabaseReferenceWorker, DataModelWorker, DDLGeneratorWorker, DictionaryWorker, DmoAsmWorker, ExpressionConversionWorker, FileOperationsWorker, I18nWorker, ImportWorker, IndexSelectionWorker, JavaPatternWorker, NameConverterWorker, NameMappingWorker, P2OAccessWorker, PreprocessorHintsWorker, ProgressPatternWorker, PropsWorker, ReportWorker, SchemaWorker, ServiceSupport, StatisticsHelper, TemplateWorker, UastHintsWorker, UnreachableCodeWorker, XmlPatternWorker

public interface PatternWorker

Each pattern engine worker class which provides variable and/or user function resolution support must implement this interface to perform initialization and termination processing, and to receive notifications from the pattern engine of processing events, such as a new AST being processed, or a new level of a call tree being processed. The worker is also given a chance to resolve expression constant values to literal values.

Method Summary

Modifier and Type	Method and Description
default void	finish() This method is called once (and only once) per invocation of the pattern engine's PatternEngine.run() method, after all rulesets are processed, and after the pattern engine's own global post-rules are processed.
java.lang.Object	getLibrary() This method should return a worker library to be registered with the expression engine's symbol resolver, if the implementation wishes to expose bean-like properties or user functions to user expressions.
default void	initialize() This method is called once (and only once) per invocation of the pattern engine's PatternEngine.run() method, immediately after the worker object is constructed.
default void	leaveAst(Aast ast) This method is called each time an AST walk is complete, to permit cleanup scoped to that AST walk.
java.lang.Object	resolveConstant(java.lang.String constant) This method is called each time the pattern engine needs to resolve a string constant into a numeric, boolean, or string literal value.
default void	visitAst(Aast ast) This method is called each time a new AST is visited, just before the pattern engine processes that AST.

Method Detail

initialize

default void initialize()

This method is called once (and only once) per invocation of the pattern engine's PatternEngine.run() method, immediately after the worker object is constructed. This hook is provided to give the worker implementation an opportunity to register symbol resolution libraries with the pattern engine's symbol resolver, as well as to perform any internal initialization.

finish

default void finish()

This method is called once (and only once) per invocation of the pattern engine's PatternEngine.run() method, after all rulesets are processed, and after the pattern engine's own global post-rules are processed. This hook is provided to allow the worker implementation to perform any necessary resource cleanup or other post-processing. It is safe to assume that no rule will be executed after this method completes.

getLibrary

java.lang.Object getLibrary()

This method should return a worker library to be registered with the expression engine's symbol resolver, if the implementation wishes to expose bean-like properties or user functions to user expressions.

It is invoked by a RuleContainer when it registers the pattern worker implementation.

Returns:

A worker library object, or null if the pattern worker implementation does not need to register a library.

resolveConstant

java.lang.Object resolveConstant(java.lang.String constant)

This method is called each time the pattern engine needs to resolve a string constant into a numeric, boolean, or string literal value.

It must return an object of the following type (or null):

• Integer
• Long
• Float
• Double
• Boolean
• String

Parameters:

constant - A string representing a constant to be resolved.

Returns:

A numeric, boolean, or string literal, or null if constant was not recognized as a placeholder for a literal.

visitAst

default void visitAst(Aast ast)

This method is called each time a new AST is visited, just before the pattern engine processes that AST. At the time this method is invoked, the resolver is not yet configured with the any source or target AST node, so the source AST is passed as a parameter, in case the worker needs to extract information.

Parameters:

ast - The root node of the source AST about to be processed by the pattern engine By convention, the worker should not modify this AST now or during the walk.

leaveAst

default void leaveAst(Aast ast)

This method is called each time an AST walk is complete, to permit cleanup scoped to that AST walk.

Parameters:

ast - The root node of the copy AST just processed by the pattern engine. This is not the same AST instance passed to visitAst(Aast) at the beginning of the walk; this AST may have been annotated and otherwise modified during the walk.