Macker Guide

Regular Expressions

• Macker's Regex Syntax
• Using an Alternate Syntax

Macker's Regex Syntax

Part of Macker's power is its ability to apply rules to a whole categories of classes which have certain roles or characteristics. Macker relies on you to use naming and packaging conventions to make these roles and layers well-defined -- the programmer still has to think a bit about what they're doing! (Macker will is also able to look at some attributes other than name; see filters. Strong AI which intuits the role of a particular class, however, is not currently in scope.)

At the heart of class categorization is a simple regular expression syntax, governed by just a few rules:

• Macker always matches fully qualified class names (e.g. "java.lang.String").
• Names separate into parts (e.g. "java", "lang", "String"). The wildcard * matches zero or more characters within a part, while ** matches across part boundaries.
• A dot matches a part boundry. There is an implicit boundary at the beginning of the class name (but not at the end).
• A Macker expression always matches the entire name. (To match on substrings, add a ** prefix and suffix.)
• Expressions are case-sensitive.

Here are a few examples to give you the idea:

This regex...	...will match these classes...	...but not these.
java.lang.*	java.lang.String	java.lang.reflect.Method java.language.MadeUpClass
java.lang.**	java.lang.String java.lang.reflect.Method	java.language.MadeUpClass
java.lang**	java.lang.String java.lang.reflect.Method java.language.MadeUpClass
String	String (a hypothetical class named "String" not in a package)	java.lang.String (the actual Java language String class)
java.lang.String	java.lang.String	String
*String*	String	java.lang.String java.lang.StringBuffer java.text.AttributedString
**String*	String java.lang.String java.lang.StringBuffer java.text.AttributedString
**String	String java.lang.String java.text.AttributedString	java.lang.StringBuffer
**.String*	String java.lang.String java.lang.StringBuffer	java.text.AttributedString

Note that the Macker regex syntax currently does not support any sort of "OR" construct. This is because one can accomplish the same thing using composite patterns (explained in the next section). I might consider adding this functionality to the actual regex syntax if there is demand for it.

Using an Alternate Syntax

Macker does not currently support any alternate regex syntaxes. In the future, it will include support for Java regex and/or Apache regexp. (Although Macker currently uses Apache regexp internally, I'm holding off on exposing its syntax as part of Macker's published API.)